Testing And Adjusting

Usage:

Introduction

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When servicing or repairing electric power generation equipment, do the following:

a. Make sure the unit is off-line (disconnected from utility power service and/or other generators) and either locked out or tagged DO NOT OPERATE.
b. Make sure the generator engine is stopped.
c. Make sure all batteries are disconnected.
d. Make sure all capacitors are discharged.

When power generation equipment is in operation to make tests and/or adjustments, high voltage and current are present. Make sure the testing equipment is designed for and correctly operated for the high voltage and current tests. Failure of improper test equipment presents a high voltage shock hazard to its user.

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When the engine-generator, or any source to which the engine-generator is synchronized to, is operating, voltages up to 600V are present in the control panel.

Do NOT short these terminals with line voltage to ground with any part of the body or any conductive material. Loss of life or injury could result from electrical shock or injury from molten metal.

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Do NOT connect generator to a utility electrical distribution system, unless it is isolated from the system. Personal injury or death is possible by electrical feedback into the distribution system.

Open and secure main distribution system switch or, if the connection is permanent, install a double throw transfer switch to prevent electrical feedback. Some generators are specifically approved by a utility to run in parallel with the distribution system and isolation is NOT required. Always check with the utility as to the applicable circumstances.

Service Tools

Fault Identification

GSC Display Area With Service Mode Descriptions Of Keypad
(1) Dedicated shutdown indicators. (2) Fault shutdown indicator. (3) Fault alarm indicator. (4) Upper display. (5) "DIAG" indicator. (6) Lower display.

Faults that are detected and diagnosed by the genset control (GSC) are shown to service personnel in the display area of the GSC. The GSC uses dedicated shutdown indicators (1), fault shutdown indicator (2), fault alarm indicator (3), "DIAG" indicator (5), upper display (4) and lower display (6) to tell service personnel about a fault. Perform the following procedure to identify the fault detected by the GSC.

NOTE: "DIAG" indicator (5) functions (either FLASHING or ON CONTINUOUSLY) whenever diagnostic information is available from the GSC.

1. Note which of the indicators are functioning on the left side of the GSC.

2. View the fault code on upper display (4) of the GSC. If the fault alarm indicator is FLASHING and no fault code is present, press the alarm codes key to see the fault code.

3. Note whether or not "DIAG" indicator (5) is FLASHING, ON CONTINUOUSLY, or ABSENT.

4. On the Fault Identification chart, look at the first column and locate the fault indicator that is functioning.

5. Go across to the second column in the chart and find the fault code that is presently shown on upper display (4).

6. Go across to the third column in the chart which describes the status of "DIAG" indicator (5).

7. Read the last two columns to find the type of fault and the corresponding topic within this module.

Diagnostic Fault Troubleshooting

Diagnostic fault codes are associated with failed electrical components or circuits, that provide information to or receive information from the GSC. The diagnostic fault code closely identifies the cause of the fault.

Each diagnostic fault code consists of a component identifier (CID) and a failure mode indicator (FMI) and an active/inactive status indicator ("DIAG") that are shown on the upper display. The CID tells which component in the system is faulty and the FMI describes the nature of the fault. When the "DIAG" indicator is FLASHING, the fault is active (present now). When the "DIAG" indicator is ON CONTINUOUSLY, the fault is inactive and the CID FMI is recorded in the fault log. To view the fault log, see Fault Log Viewing - OP1 within the topic Service Mode. When the "DIAG" indicator is absent (not showing), there are NO diagnostic fault codes detected or recorded. Service personnel interpret the identifiers to assist with troubleshooting.

When a diagnostic fault occurs (is active), the GSC FLASHES the "DIAG" indicator. The GSC determines the type of fault (alarm or shutdown) and FLASHES the corresponding fault alarm indicator or fault shutdown indicator. For a shutdown type of diagnostic fault, the CID FMI is immediately shown on the upper display. For an alarm type of diagnostic fault, the alarm codes key is pressed first and then the CID FMI is shown on the upper display.

The GSC has a fault log to help with troubleshooting of diagnostic faults. Inactive diagnostic fault codes (CID FMI) are recorded in the fault log for viewing at a later time. Also, the number of occurrences are totalled and shown on the upper display with the CID and FMI. An active diagnostic alarm fault ("DIAG" indicator is FLASHING) becomes inactive ("DIAG" indicator is ON CONTINUOUSLY) when the fault is no longer occurring and also for diagnostic shutdown faults the ECS must be turned to OFF/RESET. See Fault Log Viewing - OP1 within the topic Service Mode.

During troubleshooting, it is necessary to disconnect the harness connector (40 contact) from the GSC and faults are created. Because of internal circuitry, the GSC recognizes this condition (connector removed) as a FMI 03 (signal too high) fault for certain components. This fact is also used as a troubleshooting aid. Clear these created faults after the particular fault is corrected and cleared. In a properly operating system when the harness connector is removed from the GSC, the following diagnostic fault codes are recorded:

CID 100 FMI 3 Engine Oil Pressure SensorCID 110 FMI 3 Engine Coolant Temperature SensorCID 111 FMI 3 Engine Coolant Loss Sensor (if equipped)CID 190 FMI 3 Engine Magnetic PickupCID 336 FMI 2 Engine Control Switch

After a diagnostic fault is investigated and/or corrected, clearing it from the fault log will avoid confusion during a future service call. The "DIAG" indicator is OFF (absent) when all diagnostic faults are cleared from the fault log and no active diagnostic faults exist. See Fault Log Clearing OP4 within the topic Service Mode.

Diagnostic Faults

Upper Display With Diagnostic Fault Code "CID 190 FMI 3" Showing

CID 100 Engine Oil Pressure Sensor (EOPS)

System Schematic For Engine Oil Pressure Sensor (EOPS)

System Operation

The EMCP II system monitors engine oil pressure to protect the engine in case of an oil pressure problem. The oil pressure sensor is mounted on an oil gallery of the engine. The exact location of the engine oil pressure sensor varies depending on the engine model.

The sensor is powered by an 8 volt sensor supply from the GSC. The oil pressure signal is a pulse-width-modulated (PWM) signal. The base frequency of the signal is 500 ± 150 Hz. As pressure changes, the duty cycle of the signal varies from 10 to 95 percent.

0 kPa (0 psi) is approximately 13% duty cycle (approximately 1.0 DCV).

690 kPa (100 psi) is approximately 85% duty cycle.

NOTE: The GSC is usually programmed to treat an oil pressure sensor fault as an alarm fault (P04 = 0). If the GSC is programmed to shutdown (P04 = 1) for an oil pressure sensor fault, then it is not necessary to press the alarm codes key to see the CID FMI. The CID FMI are automatically shown on the upper display.

NOTE: Faults are created when the harness connector (40 contact) is disconnected from the GSC during these troubleshooting procedures. Clear these created faults after the particular fault is corrected and cleared. In a properly operating system when the harness connector is removed from the GSC, the following diagnostic fault codes are recorded:

FMI 2 (Signal Out Of Range)

The possible cause of a CID 100 FMI 2 fault is the base frequency or the duty cycle of the sensor signal is beyond accepted limits. Clear the fault from the fault log after troubleshooting is complete.

Begin performing these procedures only when CID 100 FMI 2 is showing and the "DIAG" indicator is FLASHING (fault is active) on the upper display. The GSC treats a CID 100 FMI 2 fault as an alarm fault. Active alarm faults are shown on the display when the alarm codes key is pressed and the ECS switch is in any position except the OFF/RESET position. For an inactive fault, the problem may be intermittent. To troubleshoot an inactive fault, use the preceding system schematic and see the topic Electrical Connector Inspection.

NOTE: If desired, this procedure can be replaced by troubleshooting the sensor signal with a meter capable of measuring frequency and duty cycle. See the topic PWM Sensor Test.

NOTE: If a sensor supply fault (CID 269) is active, correct it prior to proceeding with this CID 110 fault.

1. CHECK GSC AND HARNESS - Make sure that CID 100 FMI 2 is showing on the display. Turn the ECS to the OFF/RESET position. Disconnect the sensor from the engine harness (the sensor remains fastened to the engine). Turn the ECS to the STOP position. Press the alarm codes key (not required for shutdown faults). Monitor the display to see if CID 100 FMI 2 is no longer showing (became inactive) and CID 100 FMI 3 is now showing (active).

* OK; a 100 03 fault is showing and the 100 02 fault is not showing. The GSC and the harness function properly. Therefore, the sensor is faulty. Replace the sensor. (If desired, more sensor testing is available; see the topic PWM Sensor Test.) STOP.

* NOT OK; the 100 02 fault remains showing. The harness or the GSC is faulty. Go to Step 2.

2. CHECK GSC - Turn the ECS to the OFF/RESET position. Disconnect the harness connector from the GSC. Turn the ECS to the STOP position. Press the alarm codes key. Monitor the display to see if CID 100 FMI 2 is no longer showing (inactive) and CID 100 FMI 3 is now showing (active).

* OK; a 100 03 fault is showing and the 100 02 fault is not showing. The GSC functions properly. Therefore, the signal wire is faulty in the harness. Troubleshoot the signal wire in the harness between the sensor connector and the GSC connector. Also check the electrical connectors and terminals; see the topic Electrical Connector Inspection. STOP.

* NOT OK; the 100 02 fault remains showing. The GSC is faulty. Replace the GSC; see the topic Generator Set Control Replacement. STOP.

FMI 3 (Signal Too High)

The possible cause of a CID 100 FMI 3 fault is a short to battery positive (B+) or an open circuit of the sensor signal. Clear the fault from the fault log after troubleshooting is complete.

Begin performing these procedures only when CID 100 FMI 3 is showing and the "DIAG" indicator is FLASHING (fault is active) on the upper display. The GSC treats a CID 100 FMI 3 fault as an alarm fault. Active alarm faults are shown on the display when the alarm codes key is pressed and the ECS switch is in any position except the OFF/RESET position. For an inactive fault, the problem may be intermittent. To troubleshoot an inactive fault, use the preceding system schematic and see the topic Electrical Connector Inspection.

NOTE: If a sensor supply fault (CID 269) is active, correct it prior to proceeding with the CID 100 fault.

1. CHECK SUPPLY CIRCUIT - Turn the ECS to OFF/RESET and then to the STOP position. Disconnect the sensor from the engine harness (the sensor remains fastened to the engine). At the engine harness side of the sensor connector, measure the voltage (DCV) between contact A (supply) and contact B (sensor ground). The voltage should measure 8.0 ± 0.5 DCV.

* OK; voltage is 8.0 ± 0.5 DCV. The supply circuit functions properly. Go to Step 2.

* NOT OK; voltage is NOT 8.0 ± 0.5 DCV. The supply circuit is faulty. Check the upper display for a sensor supply fault (CID 269) and correct it. If a sensor supply fault (CID 269) is not showing on the upper display, then the engine harness has an open circuit. Go to Step 4.

2. CHECK SIGNAL CIRCUIT - The ECS remains in the STOP position and the sensor remains disconnected from the engine harness. At the engine harness side of the sensor connector, measure the voltage (DCV) between contact C (signal) and contact B (sensor ground). The voltage should measure 7.0 ± 0.5 DCV.

* OK; voltage is 7.0 ± 0.5 DCV. The signal circuit functions properly. Verify this result by checking to see if the fault remains present. Reconnect the sensor. Turn the ECS to OFF/RESET and then to STOP. If the CID 100 FMI 3 fault is still showing on the upper display, the sensor is faulty. Replace the sensor. STOP.

* NOT OK; voltage is equal to battery positive (B+). The engine harness is faulty. The signal circuit within the engine harness is shorted to battery positive (B+). Troubleshoot and repair the engine harness. STOP.

* NOT OK; voltage is NOT 7.0 ± 0.5 DCV and is NOT equal to battery positive (B+). The GSC or the harness is faulty. Go to Step 3.

3. CHECK FOR SHORTED HARNESS - When performing this Step, see the preceding System Schematic. The sensor remains disconnected from the engine harness. Turn the ECS to OFF/RESET. Disconnect the harness connector from the GSC. At the GSC harness connector, measure the resistance from signal contact 8 to all other contacts of the connector. The resistance should measure 5k ohms or greater.

* OK; all resistance measurements are correct. The harness functions properly. Go to Step 4.

* NOT OK; one or more of the resistance measurements are NOT correct. The harness wiring with the incorrect resistance is shorted in the harness. Troubleshoot and repair the faulty harness wiring between the sensor connector and the GSC connector. STOP.

4. CHECK FOR OPEN HARNESS - When performing this Step, see the preceding System Schematic. The ECS remains in the OFF/RESET position. The sensor remains disconnected from the engine harness and the GSC remains disconnected from the harness connector. The resistance of a single harness wire should measure 5 ohms or less. Measure the resistance of the following circuits in the harness:

a. Ground circuit, from contact B of the sensor harness connector to contact 31 of the GSC harness connector.

b. Signal circuit, from contact C of the sensor harness connector to contact 8 of the GSC harness connector.

c. Sensor supply circuit, from contact A of the sensor harness connector to contact 9 of the GSC harness connector.

* OK; all harness resistance measurements are 5 ohms or less. The harness functions properly. Go to Step 5.

* NOT OK; one or more of the resistance measurements are greater than 5 ohms. The harness wiring with the incorrect resistance measurement is open (faulty). Troubleshoot and repair the faulty harness wiring between the sensor connector and the GSC connector. STOP.

5. CHECK ELECTRICAL CONNECTORS - Check the electrical connectors, terminals and wiring; see the topic Electrical Connector Inspection.

* OK; all connectors, terminals and wiring function properly. Connect all harness connectors that were previously disconnected. Start the engine. If the 100 03 fault is still showing, replace the GSC. See the topic Generator Set Control Replacement. STOP.

* NOT OK; Repair the faulty area. STOP.

FMI 4 (Signal Too Low)

The possible cause of a CID 100 FMI 4 fault is a short to battery negative (B-) of the sensor signal. Clear the fault from the fault log after troubleshooting is complete.

Begin performing these procedures only when CID 100 FMI 4 is showing and the "DIAG" indicator is FLASHING (fault is active) on the upper display. The GSC treats a CID 100 FMI 4 fault as an alarm fault. Active alarm faults are shown on the display when the alarm codes key is pressed and the ECS switch is in any position except the OFF/RESET position. For an inactive fault, the problem may be intermittent. To troubleshoot an inactive fault, use the preceding system schematic and see the topic Electrical Connector Inspection.

NOTE: If a sensor supply fault (CID 269) is active, correct it prior to proceeding with the CID 100 fault.

1. CHECK GSC AND HARNESS - Make sure that CID 100 FMI 4 is showing on the display. Turn the ECS to the OFF/RESET position. Disconnect the sensor from the engine harness (the sensor remains fastened to the engine). Turn the ECS to the STOP position. Press the alarm codes key. Monitor the display to see if CID 100 FMI 4 is no longer showing (inactive) and CID 100 FMI 3 is now showing (active).

* OK; a 100 03 fault is showing and the 100 04 fault is not showing. The GSC and the harness function properly. Therefore the sensor is faulty. Replace the sensor. (If desired, more sensor testing is available, see the topic PWM Sensor Test.) STOP.

* NOT OK; the 100 04 fault remains showing. The harness or the GSC is faulty. Go to Step 2.

2. CHECK GSC - Turn the ECS to the OFF/RESET position. Disconnect the harness connector from the GSC. Turn the ECS to the STOP position. Press the alarm codes key. Monitor the display to see if CID 100 FMI 4 is no longer showing (inactive) and CID 100 FMI 3 is now showing (active).

* OK; a 100 03 fault is showing and the 100 04 fault is not showing. The GSC functions properly. Therefore, the signal wire is shorted to battery negative (B-) in the harness. Troubleshoot the signal wire in the harness between the sensor connector and the GSC connector. Also check the electrical connectors and terminals; see the topic Electrical Connector Inspection. STOP.

* NOT OK; the 100 04 fault remains showing. The GSC is faulty. Replace the GSC; see the topic Generator Set Control Replacement. STOP.

CID 110 Engine Coolant Temperature Sensor (ECTS)

System Schematic For Engine Coolant Temperature Sensor (ECTS)

System Operation

The EMCP II system monitors engine coolant temperature to protect the engine in case of a coolant temperature problem. The coolant temperature sensor is mounted in the water jacket, towards the front of the engine. The exact location of the engine coolant temperature sensor varies depending on the engine model.

The sensor is powered by an 8 volt sensor supply from the GSC. The coolant temperature signal is a pulse-width-modulated (PWM) signal. The base frequency of the signal is 455 Hz (370 to 550 Hz). As temperature changes, the duty cycle of the signal varies from 10 to 95 percent.

-40°C (-40°F) is approximately 10% duty cycle (approximately 1.0 DCV).

135°C (275°F) is approximately 93% duty cycle.

NOTE: The GSC is usually programmed to treat a fault with the coolant temperature sensor as an alarm fault (P04 = 0). If the GSC is programmed to shutdown (P04 = 1) for a fault with the coolant temperature sensor, then it is not necessary to press the alarm codes key to see the CID FMI. The CID FMI are automatically shown on the upper display.

FMI 2 (Signal Out Of Range)

The possible cause of a CID 110 FMI 2 fault is the base frequency or the duty cycle of the sensor signal is beyond accepted limits. Clear the fault from the fault log after troubleshooting is complete.

Begin performing these procedures only when CID 110 FMI 2 is showing and the "DIAG" indicator is FLASHING (fault is active) on the upper display. The GSC treats a CID 110 FMI 2 fault as an alarm fault. Active alarm faults are shown on the display when the alarm codes key is pressed and the ECS switch is in any position except the OFF/RESET position. For an inactive fault, the problem may be intermittent. To troubleshoot an inactive fault, use the preceding system schematic and see the topic Electrical Connector Inspection.

NOTE: If desired, this procedure can be replaced by troubleshooting the sensor signal with a meter capable of measuring frequency and duty cycle. See the topic PWM Sensor Test.

NOTE: If a sensor supply fault (CID 269) is active, correct it prior to proceeding with this CID 110 fault.

1. CHECK GSC AND HARNESS - Make sure that CID 110 FMI 2 is showing on the display. Turn the ECS to the OFF/RESET position. Disconnect the sensor from the engine harness (the sensor remains fastened to the engine). Turn the ECS to the STOP position. Press the alarm codes key. Monitor the display to see if CID 110 FMI 2 is no longer showing (inactive) and CID 110 FMI 3 is now showing (active).

* OK; a 110 03 fault is showing and the 110 02 fault is not showing. The GSC and the harness function properly. Therefore, the sensor is faulty. Replace the sensor. (If desired, more sensor testing is available, see the topic PWM Sensor Test.) STOP.

* NOT OK; the 110 02 fault remains showing. The harness or the GSC is faulty. Go to Step 2.

2. CHECK GSC - Turn the ECS to the OFF/RESET position. Disconnect the harness connector from the GSC. Turn the ECS to the STOP position. Press the alarm codes key. Monitor the display to see if CID 110 FMI 2 is no longer showing (inactive) and CID 110 FMI 3 is now showing (active).

* OK; a 110 03 fault is showing and the 110 02 fault is not showing. The GSC functions properly. Therefore, the signal wire is faulty in the harness. Troubleshoot the signal wire in the harness between the sensor connector and the GSC connector. Also check the electrical connectors and terminals; see the topic Electrical Connector Inspection. STOP.

* NOT OK; the 110 02 fault remains showing. The GSC is faulty. Replace the GSC; see the topic Generator Set Control Replacement. STOP.

FMI 3 (Signal Too High)

The possible cause of a CID 110 FMI 3 fault is a short to battery positive (B+) or an open circuit of the sensor signal. Clear the fault from the fault log after troubleshooting is complete.

Begin performing these procedures only when CID 110 FMI 3 is showing and the "DIAG" indicator is FLASHING (fault is active) on the upper display. The GSC treats a CID 110 FMI 3 fault as an alarm fault. Active alarm faults are shown on the display when the alarm codes key is pressed and the ECS switch is in any position except the OFF/RESET position. For an inactive fault, the problem may be intermittent. To troubleshoot an inactive fault, use the preceding system schematic and see the topic Electrical Connector Inspection.

NOTE: If a sensor supply fault (CID 269) is active, correct it prior to proceeding with the CID 110 fault.

* OK; voltage is 8.0 ± 0.5 DCV. The supply circuit functions properly. Go to Step 2.

* OK; voltage is 7.0 ± 0.5 DCV. The signal circuit functions properly. Verify this result by checking to see if the fault remains present. Reconnect the sensor. Turn the ECS to OFF/RESET and then to STOP. If the CID 110 FMI 3 fault is still showing on the upper display, the sensor is faulty. Replace the sensor. STOP.

* NOT OK; voltage is NOT 7.0 ± 0.5 DCV and is NOT equal to battery positive (B+). The GSC or the harness is faulty. Go to Step 3.

3. CHECK FOR SHORTED HARNESS - When performing this Step, see the preceding System Schematic. The sensor remains disconnected from the engine harness. Turn the ECS to OFF/RESET. Disconnect the harness connector from the GSC. At the GSC harness connector, measure the resistance from signal contact 7 to all other contacts of the connector. The resistance should measure 5k ohms or greater.

* OK; all resistance measurements are correct. The harness functions properly. Go to Step 4.

a. Ground circuit, from contact B of the sensor harness connector to contact 31 of the GSC harness connector.

b. Signal circuit, from contact C of the sensor harness connector to contact 7 of the GSC harness connector.

c. Sensor supply circuit, from contact A of the sensor harness connector to contact 9 of the GSC harness connector.

* OK; all harness resistance measurements are 5 ohms or less. The harness functions properly. Go to Step 5.

5. CHECK ELECTRICAL CONNECTORS - Check the electrical connectors, terminals and wiring; see the topic Electrical Connector Inspection.

* OK; all connectors, terminals and wiring function properly. Connect all harness connectors that were previously disconnected. Start the engine. If the 110 03 fault is still showing, replace the GSC. See the topic Generator Set Control Replacement. STOP.

* NOT OK; Repair the faulty area. STOP.

FMI 4 (Signal Too Low)

The possible cause of a CID 110 FMI 4 fault is a short to battery negative (B-) of the sensor signal. Clear the fault from the fault log after troubleshooting is complete.

Begin performing these procedures only when CID 110 FMI 4 is showing and the "DIAG" indicator is FLASHING (fault is active) on the upper display. The GSC treats a CID 110 FMI 4 fault as an alarm fault. Active alarm faults are shown on the display when the alarm codes key is pressed and the ECS switch is in any position except the OFF/RESET position. For an inactive fault, the problem may be intermittent. To troubleshoot an inactive fault, use the preceding system schematic and see the topic Electrical Connector Inspection.

NOTE: If a sensor supply fault (CID 269) is active, correct it prior to proceeding with the CID 110 fault.

1. CHECK GSC AND HARNESS - Make sure that CID 110 FMI 4 is showing on the display. Turn the ECS to the OFF/RESET position. Disconnect the sensor from the engine harness (the sensor remains fastened to the engine). Turn the ECS to the STOP position. Press the alarm codes key. Monitor the display to see if CID 110 FMI 4 is no longer showing (inactive) and CID 110 FMI 3 is now showing (active).

* OK; a 110 03 fault is showing and the 110 04 fault is not showing. The GSC and the harness function properly. Therefore the sensor is faulty. Replace the sensor. (If desired, more sensor testing is available, see the topic PWM Sensor Test.) STOP.

* NOT OK; the 110 04 fault remains showing. The harness or the GSC is faulty. Go to Step 2.

2. CHECK GSC - Turn the ECS to the OFF/RESET position. Disconnect the harness connector from the GSC. Turn the ECS to the STOP position. Press the alarm codes key. Monitor the display to see if CID 110 FMI 4 is no longer showing (inactive) and CID 110 FMI 3 is now showing (active).

* OK; a 110 03 fault is showing and the 110 04 fault is not showing. The GSC functions properly. Therefore, the signal wire is shorted to battery negative (B-) in the harness. Troubleshoot the signal wire in the harness between the sensor connector and the GSC connector. Also check the electrical connectors and terminals; see the topic Electrical Connector Inspection. STOP.

* NOT OK; the 110 04 fault remains showing. The GSC is faulty. Replace the GSC; see the topic Generator Set Control Replacement. STOP.

CID 111 Engine Coolant Loss Sensor (ECLS)

System Schematic For Engine Coolant Loss Sensor (ECLS)

System Operation

The EMCP II system monitors engine coolant for loss of coolant to protect the engine in case of a coolant temperature problem. The engine coolant loss function is an option and requires the presence of the optional coolant loss sensor. The coolant loss sensor is usually mounted near the top of the radiator.

The sensor is powered by an 8 volt sensor supply from the GSC. When coolant is NOT present at the sensor, a high signal (+5 DCV) is sent to the GSC. When coolant is present at the sensor, a low signal (B-) is sent to the GSC.

NOTE: The GSC is usually programmed to treat a coolant loss sensor fault as an alarm fault (P04 = 0). If the GSC is programmed to shutdown (P04 = 1) for a coolant loss sensor fault, then it is not necessary to press the alarm codes key to see the CID FMI. The CID FMI are automatically shown on the upper display.

FMI 3 (Signal Too High)

The possible cause of a CID 111 FMI 3 fault is a short to battery positive (B+) or an open circuit of the sensor signal. Clear the fault from the fault log after troubleshooting is complete.

Begin performing these procedures only when CID 111 FMI 3 is showing and the "DIAG" indicator is FLASHING (fault is active) on the upper display. The GSC treats a CID 111 FMI 3 fault as an alarm fault. Active alarm faults are shown on the display when the alarm codes key is pressed and the ECS switch is in any position except the OFF/RESET position. For an inactive fault, the problem may be intermittent. To troubleshoot an inactive fault, use the preceding system schematic and see the topic Electrical Connector Inspection.

NOTE: If a sensor supply fault (CID 269) is active, correct it prior to proceeding with the CID 111 fault.

* OK; voltage is 8.0 ± 0.5 DCV. The supply circuit functions properly. Go to Step 2.

* OK; voltage is 2.5 ± 0.5 DCV. The signal circuit functions properly. Verify this result by checking to see if the fault remains present. Reconnect the sensor. Turn the ECS to OFF/RESET and then to STOP. If the CID 111 FMI 3 fault is still showing on the upper display, the sensor is faulty. Replace the sensor. STOP.

* NOT OK; voltage is NOT 2.5 ± 0.5 DCV and is NOT equal to battery positive (B+). The GSC or the harness is faulty. Go to Step 3.

3. CHECK FOR SHORTED HARNESS - When performing this Step, see the preceding System Schematic. The sensor remains disconnected from the engine harness. Turn the ECS to OFF/RESET. Disconnect the harness connector from the GSC. At the GSC harness connector, measure the resistance from signal contact 13 to all other contacts of the connector. The resistance should measure 5k ohms or greater.

* OK; all resistance measurements are correct. The harness functions properly. Go to Step 4.

a. Ground circuit, from contact B of the sensor harness connector to contact 31 of the GSC harness connector.

b. Signal circuit, from contact C of the sensor harness connector to contact 13 of the GSC harness connector.

c. Sensor supply circuit, from contact A of the sensor harness connector to contact 9 of the GSC harness connector.

* OK; all harness resistance measurements are 5 ohms or less. The harness functions properly. Go to Step 5.

5. CHECK ELECTRICAL CONNECTORS - Check the electrical connectors, terminals and wiring; see the topic Electrical Connector Inspection.

* OK; all connectors, terminals and wiring function properly. Connect all harness connectors that were previously disconnected. Start the engine. If the 111 03 fault is still showing, replace the GSC. See the topic Generator Set Control Replacement. STOP.

* NOT OK; Repair the faulty area. STOP.

CID 168 Battery Voltage

System Schematic For Battery Voltage

System Operation

The EMCP II system monitors battery voltage to protect the EMCP II system in case of a battery or charging problem. The EMCP II system operates on either 24 or 32 DCV battery systems. The GSC measures the battery voltage it is receiving at terminal RM-1 of the relay module terminal strip on the rear of the GSC. The GSC receives battery power whenever circuit breaker 1 (CB1) is closed.

The GSC treats a CID 168 fault as an alarm fault.

FMI 3 (Voltage Too High), FMI 4 (Voltage Too Low)

Use this procedure for either a FMI 3 or FMI 4 fault. The possible cause of a CID 168 FMI 3 fault is the battery voltage is greater than 32 DCV for 24 volt systems or greater than 45 DCV for 32 volt systems. The possible cause of a CID 168 FMI 4 fault is the battery voltage is less than 18 DCV. The setpoint for system voltage (P07) specifies the genset battery voltage; 0 for 24 volts, 1 for 32 volts. Clear the fault from the fault log after troubleshooting is complete.

This procedure is used for troubleshooting an active or inactive fault. Active alarm faults are shown on the upper display when the alarm codes key is pressed and the ECS switch is in any position except the OFF/RESET position. Inactive alarm faults are viewed in the fault log while in service mode; see Fault Log Viewing OP1 within the topic Service Mode.

1. VERIFY FAULT - View the upper display and check for active battery voltage diagnostic faults (168 03 or 168 04). Also enter service mode and check the fault log for inactive battery voltage diagnostic faults (168 03 or 168 04).

* OK; battery voltage diagnostic faults (168 03 or 168 04), active or inactive, DO NOT EXIST. STOP.

* NOT OK; battery voltage diagnostic faults (168 03 or 168 04), active or inactive, DO EXIST. Go to Step 2.

2. CHECK VOLTAGE - Turn the ECS to the STOP position. Measure the three following voltages. The three voltages should measure within 2.0 volt of each other.

a. Note the battery voltage that is showing on the lower display.

b. Measure the voltage (DCV) between the terminals of the battery.

c. Measure the voltage (DCV) between terminals RM-1 (B+) and RM-28 (B-) of the relay module terminal strip on the rear of the GSC.

* OK; all voltages agree (less than 2.0 DCV difference). Go to Step 4.

* NOT OK; voltage measured at the batteries does not agree (greater than 2.0 DCV difference) with voltage measured at relay module terminal strip. Go to Step 3.

* NOT OK; voltage showing on the lower display does not agree (greater than 2.0 DCV difference) with voltage measured at relay module terminal strip. Replace the GSC; see the topic Generator Set Control Replacement. STOP.

3. CHECK HARNESS - Disconnect the B+ and B- cables from the battery. Disconnect the B+ wire from the RM-1 terminal and the B- wire from the RM-28 terminal of the relay module terminal strip on the rear of the GSC. Measure the resistance of each wire from the battery end to the terminal strip end. The resistance of a single harness wire should measure 5 ohms or less.

* OK; both resistance measurements are 5 ohms or less. An intermittent harness problem is likely. To further check the harness, go to the topic Electrical Connector Inspection. STOP.

* NOT OK; a resistance measurement is greater than 5 ohms. The harness wiring with the incorrect resistance measurement is faulty. Troubleshoot and repair the faulty harness wiring between the battery and the relay module terminal strip.

4. CHECK SYSTEM VOLTAGE - With the engine off, measure the system voltage at the battery. For 24 volt systems, the battery voltage should measure from 24.8 to 29.5 DCV. For 32 volt systems, the battery voltage should measure from 33.1 to 39.3 DCV.

* OK; battery voltage is correct. This procedure did not find the cause of the fault. The GSC is an unlikely cause of this fault. If the batteries or charging system is suspect, perform the charging system test, see the topic Charging System Test. If an intermittent harness or terminal problem is suspected, go to the topic Electrical Connector Inspection. If the fault is not discovered, clear the fault log and check for another occurrence of a CID 168 fault code. If a CID 168 fault code persists, replace the GSC. See the topic Generator Set Control Replacement. STOP.

* NOT OK; battery voltage is NOT correct. The charging system and/or the batteries are faulty. Perform the charging system test, see the topic Charging System Test.

CID 190 Engine Magnetic Pickup (MPU)

System Schematic For Engine Magnetic Pickup (MPU)

System Operation

The EMCP II system monitors engine speed to use the information when needed for other tasks. Tasks such as: activating an engine overspeed shutdown, terminating engine cranking, determining the oil step speed and causing the air shut off solenoid to engage during some fault shutdowns. The EMCP II does not control engine speed. The engine magnetic pickup is mounted on the flywheel housing of the engine.

The sensor creates a sine wave signal from passing ring gear teeth at the rate of one pulse per tooth. The sensor sends the GSC the sine wave signal in which the frequency is in direct proportion to the speed of the engine.

The GSC treats a CID 190 fault as a shutdown fault. The engine is not allowed to crank or run when either a CID 190 FMI 2 or CID 190 FMI 3 diagnostic fault is active.

NOTE: Engines equipped with an electronic governor have a separate magnetic pickup with the cable marked 973-458, 458-873, 973-407 or 873-507. The cable of the magnetic pickup used by the GSC is marked 838-873 or 838-973.

FMI 2 (Signal Out Of Range), FMI 3 (Signal Too High)

The possible cause of a CID 190 FMI 2 fault is that the frequency of the signal is beyond accepted limits (short to B-) or the air gap of the magnetic pickup is too large. The possible cause of a CID 190 FMI 3 fault is an open circuit of the signal. Clear the fault from the fault log after troubleshooting is complete.

The GSC treats a magnetic pickup fault as a shutdown fault. The engine is shut down and will not start when a CID 190 FMI 2 or a CID 190 FMI 3 fault is active.

This troubleshooting procedure is for a FMI 2 or a FMI 3 fault that is active or inactive.

1. CHECK HARNESS AND MPU - Turn the ECS to OFF/RESET. Disconnect the harness connector from the GSC. At the GSC harness connector, measure the resistance from contact 1 to contact 2. The resistance should measure 100 to 350 ohm.

* OK; resistance measurement is correct. The fault is most likely intermittent. Reconnect the harness connector to the GSC. Turn the ECS to OFF/RESET and then to STOP. Check to see if a CID 190 fault remains showing (active) on the upper display.

a. If a CID 190 fault is showing, continue with this procedure. Go to Step 2.

b. If a CID 190 fault is NOT showing, this Step has corrected the fault. STOP. (If desired, continue with this procedure. Go to Step 2.)

* NOT OK; the resistance measurement is NOT correct. The harness wiring or the MPU is faulty. Go to Step 2.

2. CHECK MPU RESISTANCE - Disconnect the MPU from the engine harness (the MPU remains fastened to the engine). At the connector of the MPU, measure the resistance between contact 1 and contact 2. The resistance should measure 100 to 350 ohm.

* OK; resistance measurement is correct. The resistance of the MPU is correct. Go to Step 3.

* NOT OK; the resistance measurement is NOT correct. Replace the MPU. Also, see the topic Magnetic Pickup (MPU) Adjustment. STOP.

3. CHECK HARNESS FOR OPEN AND SHORT - The ECS remains in the OFF/RESET position. The MPU and the GSC remain disconnected from the harness. Measure the resistance of the following circuits in the harness:

a. Check for open circuit, from contact 2 of the MPU harness connector to contact 2 of the GSC harness connector. The resistance should measure 5 ohms or less.

b. Check for open circuit, from contact 1 of the MPU harness connector to contact 1 of the GSC harness connector. The resistance should measure 5 ohms or less.

c. Check for short circuit, from contact 1 to contact 2, both of the GSC harness connector. The resistance should measure greater than 5K ohms.

* OK; all harness resistance measurements are correct. The harness functions properly. Go to Step 4.

* NOT OK; one or more of the resistance measurements are NOT correct. The harness wiring with the incorrect resistance measurement is faulty. Replace the faulty harness from the MPU to the GSC connector. STOP.

4. CHECK SHIELD AND CONNECTORS - The ECS remains in the OFF/RESET position. The MPU and the GSC remain disconnected from the harness. The harness has a shield (bare wire) which protects the MPU signal wire from electrical interference. It is important that this shield is securely fastened and makes good electrical connection to the inside enclosure of EMCP II. Do the following checks and measurements:

a. Within the EMCP II, check that the shield is securely fastened.

b. Within the EMCP II, measure the resistance from the shield to the B- terminal on the relay module terminal strip. The resistance should measure 5 ohms or less.

c. Check the connector of the MPU and the mating harness connector. Go to the topic Electrical Connector Inspection.

* OK; the shield is securely fastened, the resistance measurement is 5 ohms or less, and the connectors are proper. The shield and connectors are correct. Go to Step 5.

* NOT OK; one of the items is NOT correct. Repair or replace the harness. STOP.

5. INSPECT AND ADJUST MPU - Remove the MPU from the engine flywheel housing. Inspect for damage and remove any debris from the tip.

* OK; no damage is evident. Reinstall and adjust the MPU; see the topic Magnetic Pickup (MPU) Adjustment. Go to Step 6.

* NOT OK; the MPU is damaged. Replace the MPU. Also, see the topic Magnetic Pickup (MPU) Adjustment. STOP.

6. CHECK FAULT STATUS - Reconnect the harness connector to the GSC and the MPU. Turn the ECS to OFF/RESET and then to STOP. Check the upper display to see if a CID 190 fault remains showing (active).

* OK; If a CID 190 fault is NOT showing, these procedures have corrected the fault. STOP. (If desired, continue with this procedure. Go to Step 7.)

* NOT OK; If a CID 190 fault is showing, the fault is still active and the engine will not start. Use the process of elimination to find the faulty component. Stop when the fault is no longer showing. First, replace and adjust the MPU. Second, replace the harness. Third (last), replace the GSC.

7. CHECK SIGNAL VOLTAGE - As an additional check of the circuit, measure the signal voltage of the MPU. Make sure all harness connectors are connected. Setup a multimeter with 7X-1710 Cable Probes to measure the AC signal voltage from contact 1 to contact 2 of the GSC connector. Start and run the engine at rated speed. Measure the ACV. The voltage should measure 10 ACV or greater.

* OK; signal voltage is 10 ACV or greater. The MPU circuit checks correctly. STOP.

* NOT OK; signal voltage is less than 10 ACV. The most likely cause is improper air gap of the pickup. Repeat Step 5. STOP.

CID 248 CAT Data Link

System Schematic For CAT Data Link

NOTE: CID 248 FMI 9 replaces the former CID 560 FMI 11 for a CAT data link fault. Former CID 560 FMI 11 was mistakenly assigned to the CAT data link. These procedures apply to both CID's for the CAT data link: CID 248 FMI 9 and CID 560 FMI 11. When using these procedures for troubleshooting a former CID 560 fault, replace the number 248 with the number 560.

System Operation

On gensets so equipped, the GSC uses the CAT data link to communicate with other electronic controls such as an electronic engine control or a customer electronic control. The CAT data link consists of two wires that connect the GSC to at least one other electronic control.

FMI 9 (Abnormal Update)

The possible cause of a CID 248 FMI 9 fault is a short to battery positive (B+) or battery negative (B-) of either of the two CAT data link wires. The GSC cannot detect an open in the circuit of the CAT data link. Troubleshoot and repair the wiring, see the Generator Set Wiring Diagram in the Schematic & Wiring Diagrams section.

Clear the fault from the fault log after troubleshooting is complete. The GSC treats a CID 248 fault as an alarm fault. Active alarm faults are shown on the display when the alarm codes key is pressed and the ECS switch is in any position except the OFF/RESET position.

CID 268 GSC Internal Memory

System Operation

A portion of memory within the GSC stores the setpoints of important genset conditions including engine setpoint programming (OP5), spare input/output programming (OP6) and voltmeter/ammeter programming (OP8). The GSC detects a CID 268 fault when the setpoint data is invalid or out of range. After detecting a CID 268 fault, the GSC sets all the setpoints to the default value. The setpoints and the default values are:

P01 - Fuel Solenoid Type. Default value is 1 (ETS).P02 - Units Shown. Default value is 0 (English).P03 - Shutdown Override For Engine Fault. Default value is 0 (shutdown).P04 - Shutdown Override For Sensor Fault. Default value is 0 (override).P05 - Coolant Loss Sensor. Default value is 0 (not installed).P06 - Shutdown Override For Coolant Loss Fault. Default value is 0 (shutdown).P07 - System Voltage. Default value is 0 (24V).P08 - Upper Display Enable/Disable. Default value is 0 (enable).P09 - Ring Gear Teeth. Default value is 136 teeth.P10 - Engine Overspeed. Default value is 2120 rpm.P11 - Crank Terminate Speed. Default value is 400 rpm.P12 - Oil Step Speed. Default value is 1350 rpm.P13 - Low Oil Pressure Shutdown At Rated Speed. Default value is 205 kPa (30 psi).P14 - Low Oil Pressure Shutdown At Idle Speed. Default value is 70 kPa (10 psi).P15 - High Water Temperature Shutdown. Default value is 107°C (225°F).P16 - Low Water Temperature Alarm. Default value is 21°C (70°F).P17 - Total Cycle Crank Time. Default value is 90 seconds.P18 - Cycle Crank Time. Default value is 10 seconds.P19 - Cooldown Time. Default value is five minutes.P20 - AC Voltage Full Scale. Default value is 700 volts.P21 - AC Current Full Scale. Default value is 600 amps.P22 - GSC Engine Number. Default value is 01.P23 - Engine Type. Default value is 0 (MUI diesel).P24 - Crank Time Delay. Default value is 5 seconds.

NOTE: Some changes have occurred to the identity and the quantity of setpoints:

P08 is engine type (0 = diesel, 1 = spark ignited) on former 103-6177, 113-4500 and 117-6200 GSC's.

P22, P23 and P24 are not present on former 103-6177, 113-4500 and 117-6200 GSC's.

SP01 - Spare Fault 1 Active State. Default value is 0 (active low).SP02 - Spare Fault 1 Response. Default value is 0 (shutdown).SP03 - Spare Fault 2 Active State. Default value is 0 (active low).SP04 - Spare Fault 2 Response. Default value is 0 (shutdown).SP05 - Spare Fault 3 Active State. Default value is 0 (active low).SP06 - Spare Fault 3 Response. Default value is 0 (shutdown).SP07 - Spare Output Active State. Default value is 0 (active low).SP08 - Spare Fault 1 Delay Time. Default value is 0 seconds.SP09 - Spare Fault 2 Delay Time. Default value is 0 seconds.SP10 - Spare Fault 3 Delay Time. Default value is 0 seconds.SP11 - Spare Output Response. Default value is 7 (cooldown).

AC01 - A-B Voltage Calibration. Default value is random.AC02 - B-C Voltage Calibration. Default value is random.AC03 - C-A Voltage Calibration. Default value is random.AC04 - A Current Calibration. Default value is random.AC05 - B Current Calibration. Default value is random.AC06 - C Current Calibration. Default value is random.

For more information on setpoints, see Setpoint Programming OP5, Spare Input/Output Programming OP6 and Voltmeter/Ammeter Programming OP8 within the topic Service Mode in the Systems Operation section.

FMI 2 (Signal Out Of Range)

The possible cause of a CID 268 FMI 2 fault is electrical interference. Clear the fault from the fault log after troubleshooting is complete. This procedure is for an active or inactive CID 268 fault.

The GSC treats a CID 268 fault as an alarm fault or a shutdown fault, depending upon the particular setpoint with corrupt data. The ring gear teeth (P09) setpoint and the engine overspeed (P10) setpoint are treated as shutdown faults when the particular data is corrupted. All other setpoints are treated as alarm faults when the particular data is corrupted.

NOTE: If the fault shutdown indicator is FLASHING and the 6 to 9 jumper is NOT installed on the ECS, then the jumper must be temporarily installed. The GSC setpoints must be programmed in OFF/RESET when a fault shutdown is active. If the fault alarm indicator is FLASHING the GSC can be programmed with the ECS in any position.

1. CHECK HOURMETER - Place the ECS in any position other than OFF/RESET. Select and view the hourmeter on the display. The hourmeter should show a reasonable numeric value.

* OK; the hourmeter shows a reasonable numeric value. Go to Step 2.

* NOT OK; the hourmeter shows "- -". Reset the hourmeter to the original value; see Hourmeter Programming OP7 within the topic Service Mode in the Systems Operation section. Go to Step 2.

NOTE: Electrical interference can also cause the hourmeter to show "- -", but it does not cause a CID 268 FMI 2 fault.

2. CHECK SETPOINTS - View the setpoints that are stored in the memory of the GSC; see Setpoint Viewing OP2 within the topic Service Mode in the Systems Operation section. Also check the spare input/output programming (OP6) and the voltmeter/ammeter programming (OP8). Compare the stored setpoints to the specified setpoints of 103-1582 Control Panel Chart (packaged within the control panel). The stored setpoints and specified setpoints should match.

* OK; all the setpoints match. Start the engine and check to see if the CID 268 FMI 02 fault is active. If the fault remains active, replace the GSC. See the topic Generator Set Control Replacement. If the fault was inactive prior to performing this procedure, then these steps should have corrected the fault. STOP.

* NOT OK; one or more of the setpoints do not match. Program the setpoints; see Setpoint Programming OP5, Spare Input/Output Programming OP6 and Voltmeter/Ammeter Programming OP8 within the topic Service Mode in the Systems Operation section. STOP.

CID 269 Sensor Power Supply

System Schematic For Sensor Power Supply

System Operation

The EMCP II system has an 8 volt DC sensor supply from the GSC that powers the three engine sensors: oil pressure, coolant temperature and the optional coolant loss sensor. The sensor power supply functions whenever power is applied to the GSC.

NOTE: The GSC is usually programmed to treat a fault with the sensor power supply (CID 269) as an alarm fault (P04 = 0). If the GSC is programmed to shutdown (P04 = 1) for a fault with the sensor power supply, then it is not necessary to press the alarm codes key to see the CID FMI. The CID FMI are automatically shown on the upper display.

FMI 3 (Voltage Too High)

The possible cause of a CID 269 FMI 3 fault is that the voltage of the sensor power supply is greater than 8.5 DCV. Clear the fault from the fault log after troubleshooting is complete.

Begin performing these procedures only when CID 269 FMI 3 is showing and the "DIAG" indicator is FLASHING (fault is active) on the upper display. The GSC treats a CID 269 FMI 3 fault as an alarm fault. Active alarm faults are shown on the display when the alarm codes key is pressed and the ECS switch is in any position except the OFF/RESET position. For an inactive fault, the problem may be intermittent. To troubleshoot an inactive fault, use the preceding system schematic and see the topic Electrical Connector Inspection.

1. CHECK THE GSC - Disconnect the harness connector from the GSC. Turn the ECS to OFF/RESET and then to the STOP position. Press the alarm codes key. Observe the upper display to see if the 269 03 fault is showing (is active).

* OK; the 269 03 fault is not showing (is inactive). The GSC is functioning properly. Therefore, the engine harness has a short to B+. Repair the engine harness. STOP.

* NOT OK; the 269 03 fault is still showing (is active). The GSC is faulty, replace the GSC. See the topic Generator Set Control Replacement. STOP.

FMI 4 (Voltage Too Low)

The possible cause of a CID 269 FMI 4 fault is that the voltage of the sensor power supply is less than 7.5 DCV. Clear the fault from the fault log after troubleshooting is complete.

Begin performing these procedures only when CID 269 FMI 4 is showing and the "DIAG" indicator is FLASHING (fault is active) on the upper display. The GSC treats a CID 269 FMI 4 fault as an alarm fault. Active alarm faults are shown on the display when the alarm codes key is pressed and the ECS switch is in any position except the OFF/RESET position. For an inactive fault, the problem may be intermittent. To troubleshoot an inactive fault, use the preceding system schematic and see the topic Electrical Connector Inspection.

1. CHECK THE GSC - Turn the ECS to OFF/RESET. Disconnect the harness connector from the GSC. Turn the ECS to STOP. Press the alarm codes key. Observe the upper display to see if the 269 04 fault is showing (is active).

* OK; the 269 04 fault is not showing (is inactive). The GSC is functioning properly. Therefore, the engine harness or a sensor is faulty. Go to Step 2.

* NOT OK; the 269 04 fault is still showing (is active). The GSC is faulty, replace the GSC. See the topic Generator Set Control Replacement. STOP.

2. CHECK SENSORS AND HARNESS - Turn the ECS to OFF/RESET. Reconnect the harness connector to the GSC. Disconnect the engine harness from the oil pressure sensor. Turn the ECS to STOP. Press the alarm codes key. Observe the upper display to see if the 269 04 fault is showing (is active).

* OK; the 269 04 fault is not showing (is inactive). The oil pressure sensor is faulty. Replace the sensor. STOP.

* NOT OK; the 269 04 fault is still showing (is active). Repeat Step 2 for the coolant temperature sensor and the optional coolant loss sensor. If the 269 04 fault becomes inactive (not showing) after one of the sensors is disconnected, replace that sensor. If the 269 04 fault remains showing after all three sensors are disconnected, then the engine harness has a short to battery negative (B-). Repair the engine harness. STOP.

CID 330 Unexpected Shutdown

NOTE: CID 566 FMI 7 replaces the former CID 330 FMI 7 for an unexpected shutdown fault. Former CID 330 FMI 7 was mistakenly assigned as an unexpected shutdown fault. The troubleshooting procedure for a CID 330 FMI 7 fault is the same as the procedure for CID 566 FMI 7 fault. Go to the CID 566 procedure.

CID 331 Engine Control Switch (ECS)

NOTE: CID 336 FMI 2 replaces the former CID 331 FMI 2 for an ECS fault. Former CID 331 FMI 2 was mistakenly assigned as an ECS fault. The troubleshooting procedure for a CID 331 FMI 2 fault is the same as the procedure for CID 336 FMI 2 fault. Go to the CID 336 procedure.

CID 333 Alarm Module (ALM)

System Operation

A National Fire Protection Association (NFPA) 99 alarm module (ALM) standard with other configurations available as an option. It is used to satisfy customer or National Fire Protection Association (NFPA) requirements by annunciating the presence of a fault.

The ALM communicates with the GSC by a serial data link with a baud rate of 244 bits per second. When the data link malfunctions, all of the indicators on the ALM that are controlled by the data link, flash at a rate of .5 Hz.

NOTE: The maximum number of modules, ALM or CIM, connected to the serial data link is three. The maximum distance between a module and the GSC is 305 m (1000 ft). If these specifications are not met, it is possible for the ALM indicators to flash and for the GSC to declare a CID 333 fault. If not in compliance with the specifications, reduce the number of modules and/or shorten the distance to them.

FMI 3 (Signal Too High), FMI 4 (Signal Too Low)

The possible cause of a CID 333 FMI 3 fault is a short to B+ of the data signal. The possible cause of a CID 333 FMI 4 fault is a short circuit to B- of the data signal. Clear the fault from the fault log after troubleshooting is complete. The GSC treats a CID 333 FMI 3 fault or CID 333 FMI 4 fault as an alarm fault.

This troubleshooting procedure is for a FMI 3 or a FMI 4 fault that is active or inactive.

NOTE: If a CID 333 FMI 3 fault or a CID 333 FMI 4 fault is showing on the upper display and no alarm module is installed, then check for a short to B+ or B- between the auxiliary terminal strip and the GSC.

1. CHECK FAULT STATUS (ACTIVE/INACTIVE) - Turn the ECS to RESET and then to STOP. Press the alarm codes key. Observe the upper display to see if the 333 03 or 333 04 fault is showing (is active). If the fault is not showing, enter service mode and view the fault log (OP1) to see if the faults are showing (is inactive).

* OK; a 333 03 or 333 04 fault has not occurred (is NOT active and is NOT inactive). STOP.

* NOT OK; a 333 03 or 333 04 fault is active. Go to Step 2.

* NOT OK; a 333 03 or 333 04 fault is inactive. Go to Step 4.

2. CHECK VOLTAGE OF DATA SIGNAL - Turn the ECS to STOP. At the ALM, measure the DC voltage from terminal 2 (positive meter lead) to terminal 7 (negative meter lead). The measured voltage should change constantly, within the range of 0 to 10 DCV.

* OK; voltage measurement is correct. Go to Step 4.

* NOT OK; voltage measurement is NOT correct. Go to Step 3.

3. CHECK VOLTAGE OF ALM AND GSC - Turn the ECS to STOP. At the ALM, remove wire #18 from terminal 2. Disconnect the harness connector from the GSC.

a. At the ALM, measure the DC voltage from terminal 2 (positive meter lead) to terminal 7 (negative meter lead). The voltage should measure 11.6 ± 0.5 DCV.

b. Measure the DC voltage from contact 35 of the GSC, to the battery negative (B-) terminal of the relay module. The measured voltage should change constantly, within the range of 0 to 5.5 DCV.

* OK; both voltage measurements are correct. Go to Step 4.

* NOT OK; voltage measured at the ALM is NOT correct. Replace the ALM. STOP.

* NOT OK; voltage measured at the GSC is NOT correct. Replace the GSC. STOP.

4. CHECK FOR B+ SHORT IN HARNESS - Turn the ECS to OFF. Disconnect the harness connector from the GSC. At the ALM, remove wire #18 from terminal 2. Measure the resistance from wire #18 at the ALM to battery positive (B+) at the relay module. Also, measure the resistance from wire #18 at the ALM to battery negative (B-) at the relay module. The resistance should measure 20k ohms or greater.

* OK; both resistance measurements are correct. Check the electrical connectors, terminals and wiring; see the topic Electrical Connector Inspection. If the indicators on the ALM still flash after the inspection, replace the ALM. STOP.

* NOT OK; one or both of the resistance measurements are less than 20k ohms. The harness wiring with the incorrect resistance measurement is shorted (faulty). Troubleshoot and repair the faulty harness wiring between the ALM and the GSC. See the Alarm Module System Schematic.

CID 334 Spare Output

System Schematic For Spare Output

System Operation

The spare output on the GSC is strictly for customer use. The spare output is programmable to activate under a variety of conditions. The default is for the output to activate when the engine is in cooldown. For more information, see Spare Input/Output Programming OP6 within the topic Service Mode in the Systems Operation section. It is the customer's and/or the dealer's responsibility to document and troubleshoot any connections to this output.

With no connections and when not active, the voltage on the spare output is approximately 3.0 volts DC. When active, the voltage on the spare output is approximately 0 volts. The spare output is capable of drawing approximately 60 mA.

FMI 3 (Signal Too High), FMI 4 (Signal Too Low)

The possible cause of a CID 334 FMI 3 fault is a short to battery positive (B+) of the spare output signal. The possible cause of a CID 334 FMI 4 fault is a short to battery negative (B-) of the spare output signal. The GSC treats a CID 334 FMI 3 fault and a CID 334 FMI 4 fault as alarm faults.

Troubleshooting of a spare output fault is straightforward. The FMI defines the fault; FMI 3 = short to B+, FMI 4 = short to B-. Use the FMI information, spare output system schematic and the customer/dealer documentation to find the exact cause of the fault.

CID 336 Engine Control Switch (ECS)

System Schematic For Engine Control Switch (ECS)

NOTE: CID 336 FMI 2 replaces the former CID 331 FMI 2 for an ECS fault. Former CID 331 FMI 2 was mistakenly assigned to the ECS. These procedures apply to both CID's for the ECS: CID 336 FMI 2 and CID 331 FMI 2. When using these procedures for troubleshooting a former CID 331 fault, replace the number 336 with the number 331.

System Operation

The Engine Control Switch (ECS) is used by the operator for manually controlling the engine. The ECS has four positions and each position connects to a corresponding input of the GSC. The selected position of the ECS connects the corresponding input of the GSC to battery negative (B-). At any time, only one of these four positions (inputs) is connected to battery negative (B-).

Each position of the ECS places the engine in a different mode. The four positions and the corresponding engine modes are:

1. OFF/RESET - The engine is shut down and the GSC is reset (upper display and fault indicators on the left side are temporarily cleared).

2. AUTO - The engine starts and runs only when the customer's remote initiate contact closes the start input on the GSC to battery negative (B-). At this time, the GSC starts the engine and it runs normally until the remote initiate contact opens. The engine then enters a cooldown time after which the engine is shut down. The GSC shows faults on the upper display and on the fault indicators as they occur. The GSC is turned on continuously with the ECS in this position.

3. MAN/START - The engine starts and runs until the operator turns the ECS to OFF/RESET, to COOLDOWN/STOP or until the GSC detects a fault shutdown. The GSC shows faults on the upper display and on the fault indicators as they occur. The GSC is turned on continuously with the ECS in this position.

4. COOLDOWN/STOP - The engine maintains rated speed for the cooldown period (programmable 0 to 30 minutes). After the cooldown period elapses, the engine is shut down. The GSC shows faults on the upper display and on the fault indicators as they occur. The GSC is turned on continuously with the ECS in this position.

5. The EFCR (Electrical Fault Cooldown Relay) is used to bypass the ECS when an optional protective relay detects a fault. This relay disconnects the ECS and places the GSC in the cooldown mode. The fault condition is annunciated by an indicating lamp and sounding of the alarm horn. The ECS must be placed in OFF/RESET prior to restarting the engine.

FMI 2 (Undefined State)

The possible causes of a CID 336 FMI 2 fault are:

a. More than one GSC input from the ECS is connected to battery negative (B-) at the same time. The one exception is the start input. The start input of the GSC is also connected to the remote initiate contact and is controlled by the customer. The GSC accepts a battery negative (B-) state from the start input and at the same time from any other ECS input.

b. None of the GSC inputs from the ECS are connected to ground.

The CID 336 FMI 2 fault is the only ECS fault detected by the GSC. Clear the fault from the fault log after troubleshooting is complete. The GSC treats a CID 336 FMI 2 fault as a shutdown fault. Use these procedures for an active or an inactive fault.

1. CHECK FOR OPEN CIRCUIT - When performing this Step, see the preceding System Schematic. If equipped, disconnect the remote initiate contacts and reconnect after troubleshooting is complete. Disconnect the harness connector from the GSC. (If equipped, disconnect the remote start contacts by removing the wires from terminal 14 of TS1.) Check that for each position of the ECS, the corresponding contact of the GSC harness connector is the only one connected to battery negative (B-). For each position of the ECS, measure the resistance from each contact (32, 33, 39 and 40) of the harness connector to battery negative (B-) of the relay module.

a. OFF/RESET position, from contact 39 to the B- terminal should measure 5 ohms or less. Contacts 32, 33 and 40 to the B- terminal should measure greater than 5k ohms.

b. AUTO position, from contact 40 to the B- terminal should measure 5 ohms or less. Contacts 32, 33 and 39 to the B- terminal should measure greater than 5k ohms.

c. MAN/START position, from contact 33 to the B- terminal should measure 5 ohms or less. Contacts 32, 39 and 40 to the B- terminal should measure greater than 5k ohms.

d. COOLDOWN/STOP position, from contact 32 to the B- terminal should measure 5 ohms or less. Contacts 33, 39 and 40 to the B- terminal should measure greater than 5k ohms.

* OK; all resistance measurements are correct. The circuits in the harness are NOT open. To further check the harness, go to the topic Electrical Connector Inspection. STOP.

* NOT OK; one or more of the resistance measurements are NOT correct. The ECS is faulty or the harness wiring with the incorrect resistance measurement is open (faulty). Troubleshoot the ECS and/or repair the faulty harness wiring between battery negative (B-) and the GSC connector. STOP.

CID 441 Electronic Governor (EG) Relay

System Operation

The GSC uses the electronic governor relay (EGR) to activate the close-for-rated speed contacts of the electronic governor. When this occurs, the electronic governor increases the engine speed from idle to rated. The electronic governor relay output is rated at 1 amp. The EGR is located within the relay module.

When engine oil pressure is greater than the setpoint for low oil pressure shutdown at idle speed (P14), the GSC activates the EGR. (Also, K1 is now shown on the lower display.) This closes the relay contacts of the EGR and tells the electronic governor to go to rated engine speed.

When engine oil pressure is less than the setpoint for low oil pressure shutdown at idle speed (P14), the GSC does not activate the EGR. (Also, K1 is not showing on the lower display.) This opens the relay contacts of the EGR and tells the electronic governor to go to idle engine speed.

NOTE: Whenever the GSC activates or attempts to activate the EGR, K1 is shown on the lower display. When the EGR is not activated, K1 is not shown.

FMI 12 (Faulty Component)

The possible cause of a CID 441 FMI 12 fault is an open or shorted coil of the EGR. The system response to this fault is:

a. If a CID 441 fault occurs while the EGR is activated, then the engine speed drops from rated to idle speed (if equipped with an electronic governor).

b. If a CID 441 fault occurs while the EGR is not activated, then the engine is able to start and run, but can not reach rated speed (if equipped with an electronic governor).

Clear the fault from the fault log after troubleshooting is complete. The GSC treats a CID 441 fault as an alarm fault. Active alarm faults are shown on the display when the alarm codes key is pressed and the ECS switch is in any position except the OFF/RESET position.

This troubleshooting procedure is for an active or inactive CID 441 fault.

1. CHECK FAULT STATUS (ACTIVE/INACTIVE) - Turn the ECS to OFF/RESET and then to STOP. Press the alarm codes key. Observe the upper display to see if the CID 441 fault is showing (is active). If the fault is not showing, enter service mode and view the fault log (OP1) to see if the fault is showing (is inactive).

* OK; a CID 441 fault has not occurred (is NOT active and is NOT inactive). STOP.

* NOT OK; a CID 441 fault is active or inactive. Go to Step 2.

2. CHECK INTERNAL CABLE OF RELAY MODULE -

NOTE: Only open the relay module in a dry environment. If the inspection and repair takes more than approximately 20 minutes, replace the desiccant bag in the GSC housing. See the topic Relay Module Replacement.

Turn the ECS to OFF/RESET. Temporarily, remove the relay module from the GSC, see the topic Relay Module Replacement. Check the cable that attaches the relay module to the GSC. The cable should be firmly seated in the connector with the clamp in place. The cable should not be damaged.

* OK; cable is correct. Reassemble the relay module to the GSC. Proceed to Step 3.

* NOT OK; Cable or clamp are NOT correct. Replace the connector clamp if it is missing. If the cable is damaged, replace the GSC. STOP.

3. EGR FUNCTIONAL CHECK - Turn the ECS to OFF/RESET. Disconnect all wires from terminals 13 and 14 of the relay module. At the relay module, measure the resistance from terminal 13 to terminal 14. Resistance should measure greater than 5k ohms.

Start and run the engine. Make sure the engine oil pressure is greater than the setpoint for low oil pressure shutdown at idle speed (P14). At the relay module, measure the resistance from terminal 13 to terminal 14. Resistance should measure less than 5 ohms.

* OK; both resistance measurements are correct. It is likely that a temporary bad electrical connection existed and this troubleshooting procedure corrected it. Check the electrical connectors, terminals and wiring; see the topic Electrical Connector Inspection. STOP.

* NOT OK; either one of the resistance measurements are NOT correct. The relay module is faulty. Replace the relay module; see the topic Relay Module Replacement. STOP.

CID 442 Generator Fault Relay (GFR)

System Schematic For Generator Fault Relay (GFR)

System Operation

The GSC uses the generator fault relay (GFR) to activate the shunt trip coil of the optional circuit breaker during a shutdown fault. This takes the generator off-line during a shutdown fault. The GFR is located within the relay module. The optional circuit breaker is located in the generator housing.

NOTE: Whenever the GSC activates or attempts to activate the GFR, K2 is shown on the lower display. When the GFR is not activated, K2 is not shown.

FMI 12 (Faulty Component)

The possible cause of a CID 442 FMI 12 fault is an open or shorted coil of the GFR. The system response to this fault is:

a. If a CID 442 fault occurs while the GFR is activated, then there is no effect on the system because the optional circuit breaker is already open and shutdown mode is functioning. The generator is already off-line.

b. If a CID 442 fault occurs while the GFR is not activated and a shutdown fault occurs, then the GFR cannot activate the shunt trip coil of the optional circuit breaker. The generator remains on-line.

Clear the fault from the fault log after troubleshooting is complete. The GSC treats a CID 442 fault as an alarm fault. Active alarm faults are shown on the display when the alarm codes key is pressed and the ECS switch is in any position except the OFF/RESET position.

This troubleshooting procedure is for an active or inactive CID 442 fault.

1. CHECK FAULT STATUS (ACTIVE/INACTIVE) - Turn the ECS to OFF/RESET and then to STOP. Press the alarm codes key. Observe the upper display to see if the CID 442 fault is showing (is active). If the fault is not showing, enter service mode and view the fault log (OP1) to see if the faults are showing (is inactive).

* OK; a CID 442 fault has not occurred (is NOT active and is NOT inactive). STOP.

* NOT OK; a CID 442 fault is active or inactive. Go to Step 2.

2. CHECK INTERNAL CABLE OF RELAY MODULE -

NOTE: Only open the relay module in a dry environment. If the inspection and repair takes more than 20 minutes, replace the desiccant bag in the GSC housing. See the topic Relay Module Replacement.

* OK; cable is correct. Reassemble the relay module to the GSC. Proceed to Step 3.

* NOT OK; Cable or clamp are NOT correct. Replace the connector clamp if it is missing. If the cable is damaged, replace the GSC. STOP.

3. GFR FUNCTIONAL CHECK - Turn the ECS to OFF/RESET. Disconnect all wires from terminal 22 of the relay module. At the relay module, measure the resistance from terminal 22 to terminal 7. Resistance should measure greater than 5k ohms.

Turn the ECS to STOP and push in the emergency stop button. At the relay module, measure the resistance from terminal 22 to terminal 7. Resistance should measure less than 5 ohms.

* NOT OK; either one of the resistance measurements are NOT correct. The relay module is faulty. Replace the relay module; see the Topic Relay Module Replacement. STOP.

CID 443 Crank Termination Relay (CTR)

System Schematic For Crank Termination Relay (CTR)

System Operation

The GSC uses the crank termination relay (CTR) to activate optional components: the auxiliary relay (AUXREL), the governor switch (GS) and the start aid switch (SAS). The CTR is located within the relay module. The AUXREL is located on the sub-panel within the control panel. The GS and SAS are located on the instrument panel.

The CTR is used to indicate that the engine is beginning to run without cranking. The GSC activates the CTR when engine speed is greater than the crank terminate setpoint (400 RPM, setpoint P11) and the starting motor relay has been deactivated. The CTR deactivates when the engine RPM reaches 0.

NOTE: Whenever the GSC activates or attempts to activate the CTR, K3 is shown on the lower display. When the CTR is not activated, K3 is not shown.

FMI 12 (Faulty Component)

The possible cause of a CID 443 fault is an open or shorted coil of the CTR. The system response to this fault is:

a. If a CID 443 fault occurs while the CTR is activated, then the engine continues to run, but the AUX and GS are deactivated. The SAS continues to function.

b. If a CID 443 fault occurs while the CTR is not activated, then the engine is able to start and run, but the AUX and the GS are not activated. The SAS continues to function.

Clear the fault from the fault log after troubleshooting is complete. The GSC treats a CID 443 fault as an alarm fault. Active alarm faults are shown on the display when the alarm codes key is pressed and the ECS switch is in any position except the OFF/RESET position.

This troubleshooting procedure is for an active or inactive CID 443 fault.

1. CHECK FAULT STATUS (ACTIVE/INACTIVE) - Turn the ECS to OFF/RESET and then to STOP. Press the alarm codes key. Observe the upper display to see if the CID 443 fault is showing (is active). If the fault is not showing, enter service mode and view the fault log (OP1) to see if the faults are showing (is inactive).

* OK; a CID 443 has not occurred (is NOT active and is NOT inactive). STOP.

* NOT OK; a CID 443 is active or inactive. Go to Step 2.

2. CHECK INTERNAL CABLE OF RELAY MODULE -

* OK; cable is correct. Reassemble the relay module to the GSC. Proceed to Step 3.

* NOT OK; Cable or clamp are NOT correct. Replace the connector clamp if it is missing. If the cable is damaged, replace the GSC. STOP.

3. CTR FUNCTIONAL CHECK - Turn the ECS to OFF/RESET. Disconnect all wires from terminal 16 of the relay module. At the relay module, measure the resistance from terminal 16 to terminal 3. Resistance should measure greater than 5k ohms.

Start and run the engine. Make sure the engine speed is greater than the setpoint for crank terminate (P11). At the relay module, measure the resistance from terminal 16 to terminal 3. Resistance should measure less than 5 ohms.

* NOT OK; either one of the resistance measurements are NOT correct. The relay module is faulty. Replace the relay module; see the Topic Relay Module Replacement. STOP.

CID 444 Starting Motor Relay (SMR)

System Schematic For Starting Motor Relay (SMR)

System Operation

The GSC uses the starting motor relay (SMR) to activate the starting motor magnetic switch (SMMS), start aid switch (SAS) (3500 product only), the prelube pump and the battery charger. The SMR is located within the relay module and the SAS (3500 product only) is located on the instrument door of the control panel. The prelube pump and the battery charger are located external to the control panel.

NOTE: Whenever the GSC activates or attempts to activate the SMR, K4 is shown on the lower display. When the SMR is not activated, K4 is not shown.

FMI 12 (Faulty Component)

The possible cause of a CID 444 FMI 12 fault is an open or shorted coil of the SMR. The system response to this fault is:

a. If a CID 444 fault occurs while the SMR is activated, then the engine stops cranking, the prelube pump is disabled and the AUTO position of the start aid switch is disabled. The battery charger continues to function.

b. If a CID 444 fault occurs while the SMR is not activated, then the engine can not crank or start, the prelube pump is disabled and the AUTO position of the start aid switch is disabled. The battery charger continues to function. If the engine is already running, then it continues to run.

Clear the fault from the fault log after troubleshooting is complete. The GSC treats a CID 444 fault as an alarm fault. Active alarm faults are shown on the display when the alarm codes key is pressed and the ECS switch is in any position except the OFF/RESET position.

This troubleshooting procedure is for an active or inactive CID 444 fault.

1. CHECK FAULT STATUS (ACTIVE/INACTIVE) - Turn the ECS to OFF/RESET and then to STOP. Press the alarm codes key. Observe the upper display to see if the CID 444 fault is showing (is active). If the fault is not showing, enter service mode and view the fault log (OP1) to see if the faults are showing (is inactive).

* OK; a CID 444 fault has not occurred (is NOT active and is NOT inactive). STOP.

* NOT OK; a CID 444 fault is active or inactive. Go to Step 2.

2. CHECK INTERNAL CABLE OF RELAY MODULE -

* OK; cable is correct. Reassemble the relay module to the GSC. Proceed to Step 3.

* NOT OK; Cable or clamp are NOT correct. Replace the connector clamp if it is missing. If the cable is damaged, replace the GSC. STOP.

3. SMR FUNCTIONAL CHECK - Turn the ECS to OFF/RESET. Disconnect all wires from terminal 18 of the relay module. Remove fuse F4 from the relay module.

a. At the relay module, measure the resistance from terminal 18 to terminal 6. Resistance should measure greater than 5k ohms.

b. Prepare to measure the resistance from terminal 18 to terminal 6 of the relay module. Resistance should measure less than 5 ohms. Turn the ECS to START and quickly measure the resistance before the starting motor relay drops out because of the cycle crank time.

* NOT OK; either one of the resistance measurements are NOT correct. The relay module is faulty. Replace the relay module; see the Topic Relay Module Replacement. STOP.

CID 445 Run Relay (RR)

System Schematic For Run Relay (RR)

System Operation

The GSC uses the run relay (RR) to activate the electronic governor (EG) and the separate switchgear logic. The RR is located within the relay module. The electronic governor (EG) is usually mounted on the subpanel within the control panel. The SAS is mounted on the instrument panel.

The GSC activates the run relay (RR) during engine cranking and running.

NOTE: Whenever the GSC activates or attempts to activate the RR, K5 is shown on the lower display. When the RR is not activated, K5 is not shown.

FMI 12 (Faulty Component)

The possible cause of a CID 445 FMI 12 fault is an open or shorted coil of the RR. The system response to this fault is:

a. If a CID 445 fault occurs while the RR is activated, then:

On gensets with an electronic governor, the engine shuts down and does not start.

On gensets with a mechanical governor, the engine continues to run and is able to start.

And any customer equipment on terminal 23 of the relay module is activated.

b. If a CID 445 fault occurs while the RR is not activated, the:

On gensets with an electronic governor, the engine can not start.

On gensets with a mechanical governor, the engine is able to start and run.

And any customer equipment on terminal 23 of the relay module remains activated.

Clear the fault from the fault log after troubleshooting is complete. The GSC treats a CID 445 fault as an alarm fault. Active alarm faults are shown on the display when the alarm codes key is pressed and the ECS switch is in any position except the OFF/RESET position.

This troubleshooting procedure is for an active or inactive CID 445 fault.

1. CHECK FAULT STATUS (ACTIVE/INACTIVE) - Turn the ECS to OFF/RESET and then to STOP. Press the alarm codes key. Observe the upper display to see if the CID 445 fault is showing (is active). If the fault is not showing, enter service mode and view the fault log (OP1) to see if the faults are showing (is inactive).

* OK; a CID 445 fault has not occurred (is NOT active and is NOT inactive). STOP.

* NOT OK; a CID 445 fault is active or inactive. Go to Step 2.

2. CHECK INTERNAL CABLE OF RELAY MODULE -

* OK; cable is correct. Reassemble the relay module to the GSC. Proceed to Step 3.

* NOT OK; Cable or clamp are NOT correct. Replace the connector clamp if it is missing. If the cable is damaged, replace the GSC. STOP.

3. RR FUNCTIONAL CHECK - Turn the ECS to OFF/RESET. Disconnect all wires from terminal 24 of the relay module. Remove fuse F4 from the relay module.

a. At the relay module, measure the resistance from terminal 24 to terminal 8. Resistance should measure greater than 5k ohms.

b. Turn the ECS to START. At the relay module, measure the resistance from terminal 24 to terminal 8. Resistance should measure less than 5 ohms.

* NOT OK; either one of the resistance measurements are NOT correct. The relay module is faulty. Replace the relay module; see the Topic Relay Module Replacement. STOP.

CID 446 Air Shutoff Relay (ASR)

System Schematic For Air Shutoff Relay (ASR)

System Operation

The GSC uses the air shutoff relay (ASR) to activate the air shutoff solenoid during a shutdown fault. The ASR is located within the relay module. The air shutoff solenoid is located within the air inlet system of the engine.

The GSC activates the air shutoff relay (ASR) for some active shutdown faults.

NOTE: Whenever the GSC activates or attempts to activate the ASR, K6 is shown on the lower display. When the ASR is not activated, K6 is not shown.

FMI 12 (Faulty Component)

The possible cause of a CID 446 FMI 12 fault is an open or shorted coil of the ASR. The system response to this fault is:

a. If a CID 446 fault occurs while the ASR is activated, then there is no effect on the system because the air shutoff is already operating and shutdown mode is functioning.

b. If a CID 446 fault occurs while the ASR is not activated, then there is no immediate effect on the system; the engine is able to start and run.

c. If a CID 446 fault occurs while the ASR is not activated and a shutdown fault occurs, then the ASR cannot energize the air shutoff solenoid.

Clear the fault from the fault log after troubleshooting is complete. The GSC treats a CID 446 fault as an alarm fault. Active alarm faults are shown on the display when the alarm codes key is pressed and the ECS switch is in any position except the OFF/RESET position.

This troubleshooting procedure is for an active or inactive CID 446 fault.

1. CHECK FAULT STATUS (ACTIVE/INACTIVE) - Turn the ECS to OFF/RESET and then to STOP. Press the alarm codes key. Observe the upper display to see if the CID 446 fault is showing (is active). If the fault is not showing, enter service mode and view the fault log (OP1) to see if the faults are showing (is inactive).

* OK; a CID 446 has not occurred (is NOT active and is NOT inactive). STOP.

* NOT OK; a CID 446 fault is active or inactive. Go to Step 2.

2. CHECK INTERNAL CABLE OF RELAY MODULE -

* OK; cable is correct. Reassemble the relay module to the GSC. Proceed to Step 3.

* NOT OK; Cable or clamp are NOT correct. Replace the connector clamp if it is missing. If the cable is damaged, replace the GSC. STOP.

3. ASR FUNCTIONAL CHECK - Turn the ECS to OFF/RESET. Disconnect all wires from terminal 19 of the relay module.

a. At the relay module, measure the resistance from terminal 19 to terminal 5. Resistance should measure greater than 5k ohms.

b. Turn the ECS to STOP. Push in the emergency stop push button (ESPB). At the relay module, measure the resistance from terminal 19 to terminal 5. Resistance should measure less than 5 ohms.

* NOT OK; either one of the resistance measurements are NOT correct. The relay module is faulty. Replace the relay module; see the Topic Relay Module Replacement. STOP.

CID 447 Fuel Control Relay (FCR)

System Operation

The GSC uses the fuel control relay (FCR) to activate the fuel solenoid (FS). The FCR is located within the relay module. The fuel solenoid is located in the fuel system of the engine.

There are two types of fuel system solenoids: energized to run (ETR) and energized to shutdown (ETS).

For ETR systems, the GSC activates the FCR which energizes the fuel solenoid to run the engine.

For ETS systems, the GSC activates the FCR which energizes the fuel solenoid to shutdown the engine.

NOTE: Whenever the GSC activates or attempts to activate the FCR, K7 is shown on the lower display. When the FCR is not activated, K7 is not shown. Also, setpoint P01 selects the fuel solenoid type: 0 = ETR or 1 = ETS.

FMI 12 (Faulty Component)

The possible cause of a CID 447 FMI 12 fault is an open or shorted coil of the FCR. The system response to this fault is:

a. For ETR systems with the FCR activated - If a CID 447 fault occurs while the engine is running, then a CID 566 (unexpected shutdown) fault is declared and shutdown mode is functioning (the engine stops).

b. For ETR systems with the FCR not activated - If a CID 447 fault occurs, then the engine can not start or run.

c. For ETS systems with the FCR activated - If a CID 447 fault occurs, then the engine is able to run and start but the fuel solenoid will not shutdown the engine.

d. For ETS systems with the FCR not activated - If a CID 447 fault occurs, then the engine is able to run and start but the fuel solenoid will not shutdown the engine.

NOTE: On 3500 engines equipped with an electronic governor, the status of the FCR has no effect on starting or running the engine.

Clear the fault from the fault log after troubleshooting is complete. The GSC treats a CID 447 fault as an alarm fault. Active alarm faults are shown on the display when the alarm codes key is pressed and the ECS switch is in any position except the OFF/RESET position.

This troubleshooting procedure is for an active or inactive CID 447 fault.

1. CHECK FAULT STATUS (ACTIVE/INACTIVE) - Turn the ECS to OFF/RESET and then to STOP. Press the alarm codes key. Observe the upper display to see if the CID 447 fault is showing (is active). If the fault is not showing, enter service mode and view the fault log (OP1) to see if the faults are showing (is inactive).

* OK; a CID 447 fault has not occurred (is NOT active and is NOT inactive). STOP.

* NOT OK; a CID 447 fault is active or inactive. Go to Step 2.

2. CHECK INTERNAL CABLE OF RELAY MODULE -

* OK; cable is correct. Reassemble the relay module to the GSC. Proceed to Step 3.

* NOT OK; Cable or clamp are NOT correct. Replace the connector clamp if it is missing. If the cable is damaged, replace the GSC. STOP.

3. FCR FUNCTIONAL CHECK - Turn the ECS to OFF/RESET. Disconnect all wires from terminal 15 of the relay module. Remove fuse F4 to prevent engine starting.

a. At the relay module, measure the resistance from terminal 15 to terminal 4. Resistance should measure greater than 5k ohms.

b. For ETR systems, turn the ECS to START. For ETS systems, turn the ECS to START and then to OFF/RESET. Make sure that K7 is showing on the lower display. At the relay module, measure the resistance from terminal 15 to terminal 4. Resistance should measure less than 5 ohms.

* NOT OK; either one of the resistance measurements are NOT correct. The relay module is faulty. Replace the relay module; see the Topic Relay Module Replacement. STOP.

CID 500 Generator Set Control (GSC)

System Operation

A CID 500 FMI 12 fault means that the GSC is no longer able to accurately measure AC voltage and current. The engine remains able to run or start.

FMI 12 (Faulty Component)

If a CID 500 FMI 12 fault occurs, replace the GSC. See the topic Generator Set Control Replacement.

Show/hide table

NOTICE

If a CID 500 FMI 12 fault occurs and the engine is running, the generator output may be at full voltage potential even if the GSC display is showing 0 AC volts and 0 AC current for all three phases.

CID 560 CAT Data Link

NOTE: CID 248 FMI 9 replaces the former CID 560 FMI 11 for a CAT data link fault. Former CID 560 FMI 11 was mistakenly assigned to the CAT data link. The troubleshooting procedure for a CID 560 FMI 11 fault is the same as the procedure for CID 248 FMI 9 fault. Go to the CID 248 procedure.

CID 566 Unexpected Shutdown

System Schematic For Unexpected Shutdown

NOTE: CID 566 FMI 7 replaces the former CID 330 FMI 7 for an unexpected shutdown fault. Former CID 330 FMI 7 was mistakenly assigned to the unexpected shutdown fault. These procedures apply to both CID's for an unexpected shutdown fault: CID 566 FMI 7 and CID 330 FMI 7. When using these procedures for troubleshooting a former CID 330 fault, replace the number 566 with the number 330.

System Operation

The purpose of the CID 566 diagnostic code is to alert the operator that the GSC did not control the engine shutdown. The GSC usually controls all engine shutdowns. If an outside influence causes engine shutdown, the GSC declares a CID 566 fault. There is only one failure mode for a CID 566 fault and it is FMI 7 (faulty mechanical response).

The sequence of events for this fault are:

1. On a running engine, the GSC detects that engine speed has dropped from rated to 0 rpm when the GSC has not called for a shutdown.

2. The GSC determines that no engine speed sensor fault is present that explains the drop in speed signal.

3. The GSC declares a CID 566 FMI 7 fault and disables the engine from running or starting.

FMI 7 (Faulty Mechanical Response)

The possible cause of a CID 566 FMI 7 fault is a mechanical portion of a component that is not responding properly. The CID 566 FMI 7 fault is the only ECS fault detected by the GSC. Clear the fault from the fault log after troubleshooting is complete. The GSC treats a CID 566 FMI 7 fault as a shutdown fault.

NOTE: This procedure requires many voltage measurements during simulated engine cranking. Starting motor fuse F4 on the relay module is removed to prevent activating the starting motor and actual engine cranking does not occur. Voltage measurements must be made quickly before the total cycle crank time (setpoint P17) elapses. The total cycle crank time is usually 90 seconds; see the topic P17 within Setpoint Programming. If a voltage measurement takes too long (more than 90 seconds) the GSC declares an overcrank fault and the overcrank shutdown indicator will FLASH. To continue with a voltage measurement, the overcrank fault must be reset by turning the ECS to OFF/RESET and then to START.

PRELIMINARY STEP. INITIAL CHECK - Before proceeding with the troubleshooting procedures, do the following:

a. Make sure that there are NO OTHER ACTIVE FAULTS (no fault codes showing on upper display, no shutdown or alarm indicators are flashing). Failure to do so may result in erroneous troubleshooting and needless replacement of parts. The operator will make many voltage measurements while the GSC is attempting to crank the engine. If the GSC detects other faults, it will prevent starting by shutting off the fuel and air to the engine. The resulting voltage measurements would then be the exact opposite of what is expected in the procedures.

b. Check the fuel level and quality.

c. Check for a plugged fuel filter.

d. Check for a plugged air filter.

e. Refer to the Engine Service Manual if there is an obvious engine or fuel system fault.

f. Check the air shutoff solenoid (if present) for activation. If the air shutoff solenoid is activated and cannot be deactivated, begin troubleshooting with Step 15. Otherwise begin troubleshooting with Step 1.

NOTE: If genset is equipped with an electronic governor, also check it's magnetic pickup.

1. VERIFY FAULT - Check the GSC for an active CID 566 FMI 7 fault. (If other faults are active, correct the other faults before proceeding).

* OK; a CID 566 FMI 7 fault is NOT showing. No active CID 566 FMI 7 fault exists. STOP.

* NOT OK; only a CID 566 FMI 7 fault is showing. Go to Step 2. If desired and if an inactive CID 566 FMI 7 fault is showing in the fault log, check the fuel/engine problem history of the genset and proceed to Step 2.

2. CHECK SYSTEM VOLTAGE - With the engine off, measure the system voltage at the battery. For 24 volt systems, the system voltage should measure from 24.8 to 29.5 DCV. For 32 volt systems, the system voltage should measure from 33.1 to 39.3 DCV. Make a note of this measurement. The system voltage measurement is used for comparison in future Steps of this procedure.

* OK; system voltage is correct. Go to Step 3.

* NOT OK; system voltage is NOT correct. For troubleshooting see the CID 168 procedure. STOP.

3. CHECK GOVERNOR AND RACK - Remove fuse F4 from the relay module. Prepare to monitor the movement of the governor linkage and the fuel rack. Turn the ECS to OFF/RESET and then to START. Observe the governor and the fuel rack.

* OK; governor linkage and fuel rack move in the "fuel on" direction. The fault is in the engine or fuel system. Refer to the corresponding Engine Service Manual. STOP.

* NOT OK; cannot see the governor linkage and fuel rack move in the "fuel on" direction. Go to Step 4.

4. IDENTIFY FUEL SYSTEM - Determine the type of fuel solenoid used on the genset: ETR (energize to run) or ETS (energize to shutoff). Check setpoint P01 for proper programming (0=ETR, 1=ETS); see Setpoint Viewing OP2 within the topic Service Mode in the Systems Operation section.

NOTE: For 3500 product only, if an electronic governor is present and a fuel solenoid is not present, go directly to Step 12.

* OK; setpoint P01 is programmed correctly (0 for ETR, 1 for ETS). Go to Step 5.

* NOT OK; setpoint P01 is NOT programmed correctly. Reprogram setpoint P01, see Setpoint Programming - OP5 within the topic Service Mode in the Systems Operation section.

5. CHECK VOLTAGE AT FUEL SOLENOID - Fuse F4 remains removed from the relay module. Prepare to measure the voltage across the terminals of the fuel solenoid on the engine. Turn the ECS to OFF/RESET and then to START. Measure the voltage.

For ETR fuel solenoids, the voltage should measure ± 2.0 DCV of the system voltage measured in Step 2.

For ETS fuel solenoids, the voltage should measure from 0 to 2.0 DCV.

* OK; voltage is correct. The fault is with the governor or fuel rack. If an electronic governor is present, go to Step 12. Refer to the appropriate Service Manual. STOP.

* NOT OK (ETR type); voltage is low. Go to Step 6.

* NOT OK (ETS type); voltage is high. Go to Step 10.

6. CHECK FUSES - Turn the ECS to OFF/RESET. Check fuses F2 and F10 on the relay module. Also, if the engine is a 3408 or 3412 and has the auxiliary fuel control relay (AFCR) installed, check F16.

* OK; none of these fuses are blown. Go to Step 7.

* NOT OK; one or more of the fuses are blown. Go to Step 8.

7 (ETR). CHECK VOLTAGE AT RELAY MODULE - Fuse F4 remains removed from the relay module. Prepare to measure the voltage from terminal 15 to the B- terminal of the relay module. The voltage should measure ± 2.0 DCV of the system voltage measured in Step 2. Turn the ECS to OFF/RESET and then to START. Measure the voltage.

* OK; voltage is correct. There is an open circuit between terminal 15 of the relay module and the fuel solenoid. Repair the circuit. See the preceding System Schematic. STOP.

* NOT OK; voltage is low. Go to Step 9.

8. TROUBLESHOOTING BLOWN FUSE - This Step continues troubleshooting from Step 6. For reference, see the preceding System Schematics and the Main Chassis Wiring Diagram in the Schematics & Wiring Diagrams section. The ECS remains in the OFF/RESET position. Remove the fuse that is blown.

If the blown fuse is F2, measure the resistance from terminal 15 of the relay module to battery negative (B-).

If the blown fuse is F10, measure the resistance from terminal 39 of the relay module to battery negative (B-).

If the blown fuse is F16 (on the sub-panel), measure the resistance from terminal 2 (load side) of the fuse holder to battery negative (B-).

For a fuse that is blowing, the circuit resistance should measure less than 3 ohms.

* If resistance is less than 3 ohms, there is a short to battery negative (B-). (NOTE: On some ETR fuel systems with a dual coil fuel solenoid, the correct normal resistance can measure less than 1 ohm.) Remove one component or wire at a time that is in series with the load side of the fuse terminal until the faulty component or wire is isolated. Repair or replace faulty component or wiring. STOP.

* If resistance is greater than 3 ohms and the fuse still blows when all wires are removed from the appropriate terminal, replace the relay module. See the topic Relay Module Replacement. STOP.

9. CHECK LOW VOLTAGE CONDITION - This Step continues troubleshooting from Step 7. Fuse F4 remains removed from the relay module. For reference, see the Main Chassis Wiring Diagram in the Schematics & Wiring Diagrams section. Prepare to make voltage measurements at the relay module. Turn the ECS to OFF/RESET and then to START.

a. At the relay module, measure the voltage from terminal 4 to the B- terminal and from terminal 31 to the B- terminal. The voltage should measure ± 2.0 DCV of the system voltage measured in Step 2.

* If voltage is NOT correct, check the wiring and recheck the fuse F2. STOP.

* If voltage is correct, go to Step b.

b. Make sure that no other faults are active. Check the GSC display for any active faults.

* If no faults are active, go to Step c.

* If a fault other than CID 566 FMI 7 is active, correct the fault. Go to the corresponding troubleshooting procedure. STOP.

c. Recheck the voltage on terminal 15 of the relay module. See Step 7.

* If the voltage is correct. There is an open circuit between terminal 15 of the relay module and the fuel solenoid. Repair the wiring. See the Main Chassis Wiring Diagram in the Schematics & Wiring Diagrams section. STOP.

* If the voltage remains low, replace the relay module. See the topic Relay Module Replacement. STOP.

10 (ETS). CHECK VOLTAGE AT RELAY MODULE - This Step continues troubleshooting from Step 5. Fuse F4 remains removed from the relay module. Prepare to measure the voltage from terminal 15 to the B- terminal of the relay module. The voltage should measure from 0 to 2.0 DCV. Turn the ECS to OFF/RESET and then to START. Measure the voltage.

* OK; voltage is correct. A wire or a component between terminal 15 of the relay module and the fuel solenoid is shorted to battery positive (B+). Repair the circuit. See the Main Chassis Wiring Diagram in the Schematics & Wiring Diagrams section. STOP.

* NOT OK; voltage is high. Go to Step 11.

11. CHECK FCR - Fuse F4 remains removed from the relay module. Remove fuse F2 from the relay module. Turn the ECS to OFF/RESET and then to START. Make sure that K7 is not shown on the lower GSC display. (If K7 is showing, make sure that no other faults are active.)

a. At the relay module, measure the resistance from terminal 4 to terminal 15. A measurement of less than 100 ohms indicates there is a faulty component shorting terminal 15 to terminal 4.

b. Disconnect the wire from terminal 4 of the relay module and watch for a change in resistance.

* OK; resistance is greater than 10k ohms. Check for a short from battery positive (B+) to terminal 15 of the relay module. Repair the shorted wiring. If the short is internal to the relay module, replace the relay module. See the topic Relay Module Replacement. STOP.

* NOT OK; resistance increases to greater than 10k ohms as the wire on terminal 4 of the relay module is removed. Repair the shorted wiring to the emergency fuel control relay (EFCR) or replace the EFCR as necessary. STOP.

* NOT OK; resistance remains less than 100 ohms. The short is internal to the relay module. Replace the relay module, see the topic Relay Module Replacement. STOP.

12. CHECK SUPPLY VOLTAGE OF ELECTRONIC GOVERNOR - This Step continues troubleshooting from Step 4. Fuse F4 remains removed from the relay module. Prepare to measure the voltage from the positive supply terminal of the electronic governor to the B- terminal of the relay module. The voltage should measure ± 2.0 DCV of the system voltage measured in Step 2. Turn the ECS to OFF/RESET and then to START. Measure the voltage.

* OK; supply voltage is correct. The fault is in the electronic governor or actuator system. For the 2301A governor, see module SENR4676. For the 2301A load sharing governor, see module SENR3585. For 524 and 1724 electrically powered governor systems, see module SENR6430. STOP.

* NOT OK; supply voltage is low. Check fuses F6 and F11 on the relay module. If blown, go to Step 8. If fuse is OK, go to Step 13.

13. CHECK VOLTAGE AT RELAY MODULE - Fuse F4 remains removed from the relay module. Prepare to measure the voltage from terminal 24 to the B- terminal of the relay module. The voltage should measure ± 2.0 DCV of the system voltage measured in Step 2. Turn the ECS to OFF/RESET and then to START. Measure the voltage.

* OK; voltage is correct. There is an open between terminal 24 of the relay module and the electronic governor. Check the wiring. See the Main Chassis Wiring Diagram in the Schematics & Wiring Diagrams section. STOP.

* NOT OK; voltage is low. Go to Step 14.

14. CHECK LOW VOLTAGE CONDITION - Fuse F4 remains removed from the relay module. For reference, see the preceding System Schematic and the Main Chassis Wiring Diagram in the Schematics & Wiring Diagrams section. Prepare to make voltage measurements at the relay module. Turn the ECS to OFF/RESET and then to START.

a. At the relay module, measure the voltage from terminal 8 to the B- terminal and from terminal 35 to the B- terminal. The voltage should measure ± 2.0 DCV of the system voltage measured in Step 2.

* If voltage is NOT correct, check the wiring and recheck the fuse F6. STOP.

* If voltage is correct, go to Step b.

b. Make sure that no other faults are active. Check the GSC display for any active faults.

* If only the CID 566 FMI 7 is active, go to Step c.

* If a fault other than CID 566 FMI 7 is active, correct the fault. Go to the corresponding troubleshooting procedure. STOP.

c. Recheck the voltage on terminal 24 of the relay module. See Step 13.

* If the supply voltage is correct. There is an open between terminal 24 of the relay module and the electronic governor. Check the wiring. See the Main Chassis Wiring Diagram in the Schematics & Wiring Diagrams section. STOP.

* If the supply voltage remains low, replace the relay module. See the topic Relay Module Replacement. STOP.

15. CHECK VOLTAGE AT AIR SHUTOFF SOLENOID - Remove fuse F4 from the relay module. Prepare to measure the voltage across the terminals of the air shutoff solenoid (air solenoid may activate for as little as 15 seconds). The voltage should measure from 0 to 2.0 DCV. Turn the ECS to OFF/RESET and then to START. Measure the voltage.

* OK; voltage is correct. If the air shutoff remains tripped or cannot be reset, the fault is in the air shutoff. Refer to the Engine Service Manual. STOP.

* NOT OK; voltage is high. Go to Step 16.

16. CHECK VOLTAGE AT RELAY MODULE - Fuse F4 remains removed from the relay module. Prepare to measure the voltage from terminal 19 to the B- terminal of the relay module. The voltage should measure 0 to 2.0 DCV when the ECS is turned to START. Turn the ECS to OFF/RESET and then to START. Measure the voltage.

* OK; voltage is correct. A wire or a component between terminal 19 of the relay module and the air shutoff solenoid is shorted to battery positive (B+). Repair the circuit. See the Main Chassis Wiring Diagram in the Schematics & Wiring Diagrams section. STOP.

* NOT OK; voltage is high. Go to Step 17.

17. CHECK ASR - Fuse F4 remains removed from the relay module. Remove fuse F3 from the relay module. Turn the ECS to OFF/RESET. Make sure that K6 is not shown on the lower GSC display. (If K6 is showing, make sure that no other faults are active.)

At the relay module, measure the resistance from terminal 5 to terminal 19. A measurement of less than 100 ohms indicates the air shutoff relay is shorted.

* OK; resistance is greater than 10k ohms. Check for a short from battery positive (B+) to terminal 19 of the relay module. Repair the shorted wiring. If the short is internal to the relay module, replace the relay module. See the topic Relay Module Replacement. STOP.

* NOT OK; resistance is less than 100 ohms. The short is internal to the relay module. Replace the relay module, see the topic Relay Module Replacement. STOP.

Spare Fault Troubleshooting

Upper Display With Spare Fault Code SP1 Showing

System Schematic For Spare Fault Inputs

A spare fault informs the operator of an undesirable condition (fault) that exists. The spare fault inputs are programmed into the GSC to meet the requirements of the customer or application. An active spare fault input causes an alarm fault or shutdown fault. For programming of the spare fault inputs, see Spare Input/Output Programming OP6 within the topic Service Mode in the Systems Operation section. It is the responsibility of the programmer (customer, operator, or service personnel) to make a note of the actual conditions that cause a spare fault code to be shown on the upper display. The GSC does not diagnose the spare fault inputs and spare faults are not recorded in the fault log.

The GSC treats an active high input state as a fault. The active state is programmable on the GSC to be either a high or low voltage level. A high level is within the range of +5 DCV to battery positive. If the input is left floating (for example an open switch), the GSC pulls the input voltage up to 10.5 DCV and the input is treated as high level. A low level on the input is B- (ground).

When a spare fault occurs (is active), the GSC determines the type of fault (alarm or shutdown) and FLASHES the corresponding fault alarm indicator or fault shutdown indicator. For a shutdown type of fault, the spare fault code is immediately shown on the upper display. For an alarm type of fault, the alarm codes key is pressed first and then the spare fault code is shown on the upper display. After a spare fault is corrected or is not present, the spare fault code is no longer shown on the upper display.

Spare fault codes are associated with the spare fault inputs. The spare fault code shown on the upper display, identifies the spare fault input that caused the alarm fault or shutdown fault. The spare fault codes are:

SP1 for spare fault 1 input.

SP2 for spare fault 2 input.

SP3 for spare fault 3 input.

When a spare fault code is showing on the upper display, check the programming notes to determine the cause. If no notes are available use the following information to help find the cause.

The SP1 fault code corresponds to contact 23 of the GSC connector which is wired to the shutdown relay.

The SP2 fault code corresponds to contact 24 of the GSC connector which is wired to terminal 25.

The SP3 fault code corresponds to contact 25 of the GSC connector which is wired to terminal 26.

NOTE: On gensets equipped with the optional protective relays, such as reverse power and over voltage, the shutdown relay (SDR) is connected to the spare fault 1 input of the GSC. And an SP1 fault code is shown when the relays have operated.

Alarm Fault Troubleshooting

Upper Display With Alarm Fault Code AL3 Showing

An alarm fault informs the operator of a condition that is about to cause a dedicated fault shutdown. An alarm fault precedes certain dedicated shutdown faults. Alarm faults are activated automatically by the GSC and depend upon certain setpoints. The GSC does not record alarm faults in the fault log.

When an alarm fault occurs (is active), the GSC FLASHES the fault alarm indicator and the corresponding alarm code is shown on the upper display after the alarm codes key is pressed. When the alarm fault is no longer active, the alarm fault code is no longer shown on the upper display.

The alarm fault codes and the related setpoints are:

AL1 - High engine coolant temperature alarm. When coolant temperature rises to within 6°C (11°F) of the P15 setpoint, a high coolant temperature alarm is issued by the GSC. Then the GSC FLASHES the fault alarm indicator and alarm code AL1 is shown on the upper display after the alarm codes key is pressed.

AL2 - Low engine coolant temperature alarm. When coolant temperature decreases to setpoint P16, then the GSC FLASHES the fault alarm indicator and alarm code AL2 is shown on the upper display after the alarm codes key is pressed.

AL3 - Low engine oil pressure alarm. When oil pressure drops to within 34 kPa (5 psi) of the P13 or P14 setpoint, a low oil pressure alarm is issued by the GSC. Then the GSC FLASHES the fault alarm indicator and alarm code AL3 is shown on the upper display after the alarm codes key is pressed.

For more information on alarm faults, see the topics Alarm Mode and Alarm Fault Codes.

Troubleshooting Procedure

If the operation of the alarm codes is suspected to be faulty perform this procedure.

1. Check for a CID 110 (temperature sensor) or CID 269 (sensor power supply) diagnostic code that is active. See the topic Diagnostic Faults.

* If one of these diagnostic codes is active, correct it prior to proceeding with this procedure.

* If neither of these diagnostic codes is active, go to Step 2.

2. Identify the alarm code suspected to be faulty.

* If alarm code AL1 or AL3 is suspected to be faulty, go to and use the procedures of the topic Dedicated Shutdown Indicator Troubleshooting.

If alarm code AL2 is suspected to be faulty, go to Step 3.

3. Functional check of the AL2 alarm code. Check and note setpoint P16 (low water temperature alarm), see Setpoint Viewing OP2 within the topic Service Mode in the Systems Operation section. Check and note the actual coolant temperature showing on the lower display. Compare the two temperatures. The actual coolant temperature showing on the lower display should be greater than setpoint P16.

* If the temperature showing on the lower display is greater than setpoint P16, then the temperatures are not correct for an AL2 alarm code. If the AL2 alarm code remains active, replace the GSC. See the topic Generator Set Control Replacement. STOP.

* If the temperature showing on the lower display is less than setpoint P16, then the temperatures are correct for an AL2 alarm code. Make sure setpoint P16 is reasonable for the local climate. Adjust if necessary or proceed to Step 4 if the setpoint is reasonable.

4. Check accuracy of temperature showing on the lower display of the GSC. Install an accurate engine coolant temperature gauge with the sensing element in an area of high coolant flow and as close as possible to the EMCP II coolant temperature sensor. Start and run the engine. Allow coolant temperature to stabilize. Compare the temperature showing on the gauge with that showing on the lower display. The temperatures should agree within 5°C (10°F).

* Temperatures agree. The engine is running cold. Refer to the Engine Service Manual to find the cause. Check the jacket water heater circuit breaker on switchgear door (if equipped). STOP.

* Temperatures do not agree. If the gauge is accurate, replace the engine coolant temperature sensor. STOP.

Dedicated Shutdown Indicator Troubleshooting

GSC Display Area With Service Mode Descriptions Of Keypad
(1) Dedicated shutdown indicators. (2) Fault shutdown indicator. (3) Fault alarm indicator. (4) Upper display. (5) Lower Display. (6) Keypad.

The dedicated shutdown indicators inform the operator which system is responsible for an engine shutdown. The symbol and nomenclature nearest to the indicator identifies the responsible system. Dedicated shutdown faults are activated automatically by the GSC and depend upon certain setpoints. When the GSC decides that operating conditions are critical, it FLASHES the corresponding shutdown indicator and shuts the engine down. The GSC does not record dedicated shutdown faults in the fault log.

The dedicated shutdown indicators (faults) are:

Low Oil Pressure

Emergency Stop

High Water Temperature

Engine Overspeed

Low Coolant Level

Overcrank

To find the cause of a dedicated shutdown fault, perform the following corresponding procedure.

Low Oil Pressure Indicator

System Schematic For Engine Oil Pressure Sensor (EOPS)

To find the cause of a low oil pressure shutdown, perform this procedure.

1. Check for a CID 100 (oil pressure sensor) or CID 269 (sensor power supply) diagnostic code that is active. See the topic Diagnostic Faults.

* If any one of these diagnostic codes is active, correct it prior to proceeding with this procedure. STOP.

* If none of these diagnostic codes is active, go to Step 2.

2. Check for obvious causes of low oil pressure. Check oil level, oil leaks and other obvious causes of low oil pressure.

* If no obvious causes exist, then go to Step 3.

* If obvious causes do exist, then correct the fault. Refer to the Engine Service Manual. STOP.

3. Check setpoints P12 (oil step speed), P13 (low oil pressure at rated speed) and P14 (low oil pressure at idle speed). View and make a note of setpoints P12, P13 and P14. See Setpoint Viewing OP2 within the topic Service Mode in the Systems Operation section. Compare the setpoint viewed with the setpoint specified on print 103-1582. The setpoints should agree. The factory setpoints are: 1350 RPM for P12, 205 kPa (30 psi) for P13 and 70 kPa (10 psi) for P14.

* If the setpoints agree, then go to Step 4.

* If the setpoints do not agree, then reprogram setpoints P12, P13 and P14. See Setpoint Programming OP5 within the topic Service Mode in the Systems Operation section. STOP.

4. Check of the low oil pressure function. Turn the ECS to OFF/RESET and then start and run the engine. Allow oil pressure to stabilize. Check and note the oil pressure showing on the lower display with the engine at idle speed and rated speed.

a. When at idle speed, compare the actual pressure showing on the lower display with that of setpoint P14 (noted in Step 3). The actual pressure showing should be greater than setpoint P14.

b. When at rated speed, compare the actual pressure showing on the lower display with that of setpoint P13 (noted in Step 3). The actual pressure showing should be greater than setpoint P13.

* If the actual pressure showing is less than the setpoint for rated speed or idle speed, then the pressures are correct for a low oil pressure shutdown. Therefore the engine should shutdown and the low oil pressure indicator should FLASH. The GSC is operating properly. Refer to the Engine Service Manual to find the cause of low oil pressure. STOP.

* If the actual pressure showing on the lower display is greater than the setpoint for rated speed or idle speed, then the pressures are not correct for a low oil pressure shutdown.

a. If the low oil pressure indicator remains FLASHING, replace the GSC. See the topic Generator Set Control Replacement. STOP.

b. If the low oil pressure indicator does not FLASH, then the problem may be intermittent. Check the harness and all electrical connections of the oil pressure circuit; see the topic Electrical Connector Inspection. STOP.

NOTE: If desired, check the accuracy of the pressure shown on the lower display of the GSC. Install an accurate engine oil pressure gauge as close as possible to the EMCP II engine oil pressure sensor.

Emergency Stop Indicator

To find the cause of a emergency stop shutdown, perform this procedure.

1. Check emergency stop push button (ESPB) and engine control switch (ECS). Turn the ESPB clockwise. The ESPB should pop out and the emergency stop indicator should be OFF. Turn the ECS to OFF/RESET and then to STOP.

* If the ESPB pops out and the emergency stop indicator is OFF, then the system is operating correctly. The problem may be intermittent. Check the harness and all electrical connections of the ESPB circuit; see the topic Electrical Connector Inspection. STOP.

* If the ESPB pops out and the emergency stop indicator is FLASHING, then go to Step 2.

* If the ESPB does not pop out, then replace the ESPB. STOP.

2. Check emergency stop indicator.

NOTE: This Step creates diagnostic fault codes. Clear these created diagnostic fault codes after troubleshooting is complete.

The ECS remains in the STOP position. Disconnect the harness connector from the GSC. Temporarily install a jumper from contact 39 of the GSC to B-(this simulates the OFF/RESET position of the ECS). Check the operation of the emergency stop indicator. The emergency stop indicator should be OFF.

* If the emergency stop indicator is OFF, then the fault is with the ESPB or the related wiring. Troubleshoot the circuit. See the Main Chassis Wiring Diagram in the Schematics And Wiring Diagram section. Repair or replace faulty components or wiring as necessary. STOP.

* If the emergency stop indicator is FLASHING, then replace the GSC. See the topic Generator Set Control Replacement.

High Water Temperature Indicator

System Schematic For Engine Coolant Temperature Sensor (ECTS)

To find the cause of a high water temperature shutdown, perform this procedure.

1. Check for a CID 110 (temperature sensor) or CID 269 (sensor power supply) diagnostic code that is active. See the topic Diagnostic Faults.

* If any one of these diagnostic codes is active, correct it prior to proceeding with this procedure. STOP.

* If none of these diagnostic codes is active, go to Step 2.

2. Check for obvious causes of high water temperature. Check water level, fan belts and other obvious causes of high water temperature.

* If no obvious causes exist, then go to Step 3.

* If obvious causes do exist, then correct the fault. Refer to the Engine Service Manual. STOP.

3. Check setpoint P15 (high water temperature). View setpoint P15 and make a note. See Setpoint Viewing OP2 within the topic Service Mode in the Systems Operation section. Compare the setpoint viewed with the setpoint specified on print 103-1582. The setpoints should agree.

* If the setpoints agree, then go to Step 4.

* If the setpoints do not agree, then reprogram setpoint P15. See Setpoint Programming OP5 within the topic Service Mode in the Systems Operation section. STOP.

4. Check of the high water temperature function. Start and run the engine. Allow water temperature to stabilize. Check and note the actual water temperature showing on the lower display. Compare the actual temperature showing on the lower display with that of setpoint P15 (noted in Step 3). The actual temperature showing on the lower display should be less than setpoint P15.

* If the actual temperature showing on the lower display reaches or is greater than setpoint P15, then the temperatures are correct for a high water temperature shutdown. Therefore the engine should shutdown and the high water temperature indicator should FLASH. The GSC is operating properly. Refer to the Engine Service Manual to find the cause of high coolant temperature. STOP.

* If the actual temperature showing on the lower display is less than setpoint P15, then the temperatures are not correct for a high water temperature shutdown.

a. If the high water temperature indicator remains FLASHING, replace the GSC. See the topic Generator Set Control Replacement. STOP.

b. If the high water temperature indicator does not FLASH, then the fault may be intermittent. Check the harness and all electrical connections of the coolant temperature circuit; see the topic Electrical Connector Inspection. STOP.

NOTE: If desired, check the accuracy of the temperature shown on the lower display of the GSC. Install an accurate engine coolant temperature gauge with the sensing element in an area of high coolant flow and as close as possible to the EMCP II coolant temperature sensor.

Engine Overspeed Indicator

To find the cause of a engine overspeed shutdown, perform this procedure.

1. Check setpoint P09 (ring gear teeth) and P10 (engine overspeed). View setpoint P09 and P10 and make a note. See Setpoint Viewing OP2 within the topic Service Mode in the Systems Operation section. Compare the setpoints viewed with the setpoints specified on print 103-1582. The setpoints should agree.

* If the setpoints agree, then go to Step 2.

* If the setpoints do not agree, then reprogram setpoints P09 and P10. See Setpoint Programming OP5 within the topic Service Mode in the Systems Operation section. STOP.

2. Check for possible causes of the engine overspeed condition; see the Engine and/or Governor Service Manuals.

* If the cause is not found, then go to Step 3.

* If the cause is found, repair or replace the necessary engine or governor components. STOP.

3. Check of the engine overspeed function.

NOTE: Take precautions to stop the engine manually when performing this Step.

If possible disable the engine from reaching rated speed. Start the engine and slowly increase the RPM to rated speed. The engine should not overspeed and the GSC should not shut down the engine or issue an overspeed fault.

* If the engine reaches rated speed and the GSC does not issue an overspeed fault and shut down the engine, then the GSC and the system are functioning properly. Perform an overspeed verification. See Engine Setpoint Verification OP9 within the topic Service Mode in the Systems Operation section. STOP.

* If the engine overspeeds and the GSC issues an overspeed fault, then see the Engine and/or Governor Service Manuals to find the cause of the problem.

* If the engine does not overspeed but the GSC issues an overspeed fault and shuts down the engine, then re-check the setpoints of Step 1. If the setpoints are correct, then replace the GSC. See the topic Generator Set Control Replacement.

Low Coolant Level Indicator

System Schematic For Engine Coolant Loss Sensor (ECLS)

To find the cause of a low coolant level shutdown, perform this procedure.

1. Check the level of the engine coolant; see the Operations & Maintenance Manual for the engine. The coolant level should be at the proper level and should be above the probe of the coolant loss sensor.

* If the coolant level is correct, then go to Step 2.

* If the coolant level is not correct, then find and correct the cause. Refer to the Engine Service Manual. STOP

2. Check for a CID 111 (coolant loss sensor) diagnostic code that is active. Turn the ECS to OFF/RESET and then to STOP. Wait 10 seconds. Check for CID 111 diagnostic code. See the topic Diagnostic Faults. The low coolant level indicator should not be FLASHING and there should be no active CID 111 diagnostic codes.

* If a CID 111 diagnostic code is active, troubleshoot the diagnostic fault. See the topic Diagnostic Fault Troubleshooting. STOP.

* If no CID 111 diagnostic codes are active and the low coolant level indicator is OFF, then the fault may be intermittent. Check the harness and all electrical connections of the low coolant level; see the topic Electrical Connector Inspection. STOP.

* If no CID 111 diagnostic codes are active and the low coolant level indicator is FLASHING, then the sensor is faulty. Replace the coolant loss sensor. STOP.

Overcrank Indicator

To find the cause of a overcrank shutdown, perform this procedure.

Before beginning the troubleshooting procedure, do the following preliminary checks.

a. Check for active diagnostic fault codes (with the exception of the 330-7 or 566-7 code) and other flashing indicators on the GSC. If either are present, then correct them first. Go to the appropriate procedure for that fault.

b. Check the fuel level and quality. Refer to the Engine Service Manual.

c. Check for a plugged fuel filter. Refer to the Engine Service Manual.

d. Check for a plugged air filter. Refer to the Engine Service Manual.

e. Check air shutoff solenoid (if equipped) for activation. The solenoid must be deactivated for the engine to start or run. See the topic CID 566 in the Diagnostic Fault Section.

f. Check prelube system (if equipped) for proper operation. See the DC Schematic - Prelube Pump in the Schematics And Wiring diagrams section or refer to the Engine Service Manual.

g. Check fuse F2 and F4 on the relay module. If either is blown, proceed to Step 4.

h. Check the engine starting and fuel system. (To check the fuel solenoid, see CID 566 within the topic Diagnostic Faults.) If there is a fault, refer to the Engine Service Manual. If there is no engine or fuel system fault, go to Step 1 of the following procedure.

1. Check setpoints P17 (total cycle crank time) and P18 (cycle crank time). View and make a note setpoints P17 and P18. See Setpoint Viewing OP2 within the topic Service Mode in the Systems Operation section. The factory setpoints are: 90 seconds for P17 and 10 seconds for P18.

NOTE: Engines equipped with prelube pumps may require crank cycle times (setpoint P18) of 30 seconds or more.

* If setpoints P17 and P18 are correct for the engine application, then go to Step 2.

* If setpoint P17 or P18 is NOT correct for the engine application, reprogram the setpoints. See Setpoint Programming OP5 within the topic Service Mode in the Systems Operation section. STOP.

2. Check voltage at battery. With the engine off, measure the system voltage at the batteries. The voltage should measure from 24.8 to 29.5 DCV for 24 volt systems or 33.1 to 39.3 DCV for 32 volt systems.

* If the system voltage is correct, then go to Step 3.

* If the system voltage is NOT correct, then further checking of the battery system is necessary. See the topic CID 168 in the Diagnostic Fault Troubleshooting section. STOP.

3. Check of the engine starting function. Disconnect the B+ wire on the pinion solenoid of the starting motor. Prepare to make the following DC voltage measurements while the engine is attempting to crank. All measurements are to B- (ground). Attach the black lead of the multimeter to B- (ground). Turn the ECS to START. Measure the voltage from B- (ground) to each of the following points in the order listed. Each of the voltages should measure the same as the system voltage noted in Step 2 ± 2.0 DCV.

NOTE: The GSC is attempting to crank whenever the K4 indicator is ON (on the lower display). Be aware of the 10 second crank cycle that is factory set and be sure that the K4 indicator is ON while making the following measurements. Have a helper observe the GSC display if necessary. More than one start may be required to complete this test.

3a. Measure at the B+ pinion solenoid wire that was previously disconnected.

* If the voltage is correct, then the starting motor is faulty. Repair or replace the starting motor. Refer to the Engine or Starting Motor Service Manual. STOP.

* If the voltage is NOT correct, then go to Step 3b.

3b. Terminal 25 of TS1 in the generator housing.

* If the voltage is correct, then the engine wire harness is faulty. Repair or replace the engine wire harness. See the Generator Set Wiring Diagram in the Schematics And Wiring Diagram section. STOP.

* If the voltage is NOT correct, then go to Step 3c.

3c. Terminal 5 of TS1 in the generator housing.

* If the voltage is correct, then the starting motor magnetic switch (SMMS) or the related wiring is faulty. Troubleshoot the SMMS and the related wiring. See the Main Chassis Wiring Diagram in the Schematics And Wiring Diagram section. STOP.

* If the voltage is NOT correct, then go to Step 3d.

3d. Terminal 18 of the relay module.

* If the voltage is correct, then the related wiring is faulty. Troubleshoot the wiring. See the system schematics. STOP.

* If the voltage is NOT correct, then go to Step 3e.

3e. Terminal 6 of the relay module.

* If the voltage is correct, then the relay module is faulty. Replace the relay module (first make sure the K4 indicator is ON). See the topic Relay Module Replacement. STOP.

* If the voltage is NOT correct, then go to Step 3f.

3f. Terminal 33 of the relay module.

* If the voltage is correct, then fuse F4 is blown. Go to Step 4.

* If the voltage is NOT correct, then the B+ terminal or the wiring to terminal 33 is faulty. Repair or replace the wiring. See the Main Chassis Wiring Diagram in the Schematics And Wiring Diagram section. STOP.

4. Troubleshoot blown fuse, check for a short to B- (ground). Remove fuse F4 from the relay module. At the relay module, measure the resistance from terminal 18 to B- (ground). For fuse F2, measure the resistance from terminal 15 to B- (ground). A short to B- (ground) will measure 5 ohms or less.

See the Main Chassis Wiring Diagram in the Schematics And Wiring Diagram section. Remove one component or wire at a time that is in series with terminal 18 until the faulty component or wire is isolated. Repair or replace faulty component or wiring. STOP.

NOTE: If a fuse still blows when all wires are removed from relay module terminal 18, replace the Relay Module. STOP.

Undiagnosed Problem Troubleshooting

Undiagnosed problems are NOT accompanied by any type of fault indicator or fault code on the GSC. To troubleshoot an undiagnosed problem, find the description that best fits the problem in the Undiagnosed Problem List and go to the corresponding procedure.

NOTE: If any fault indicator or fault code is showing on the GSC, then go to the appropriate procedure for that fault.

Undiagnosed Problem List

Problem A: Starting motor remains engaged or continues to run after engine has started.

Problem B: No engine shutdown when a shutdown fault occurs.

Problem C: Fault indicators of the remote annunciator or control panel alarm module (that are controlled by the data link) all flash at a rate of once per two seconds (0.5 Hz).

Problem D: Fault shutdown indicator on the GSC flashes at the rate of four to five times per second (4 to 5 Hz).

Problem E: 0 volts or 0 amps are showing on the display of the GSC for one or more AC phases with the genset running and the load connected.

Problem F: The AC voltage and/or current values on the GSC are inaccurate.

Problem A

Starting motor remains engaged or continues to run after engine has started.

1. CHECK RELATED SETPOINTS - Check setpoints P11 (crank terminate speed), P17 (total cycle crank time) and P18 (cycle crank time). See print 103-1582 and see Setpoint Viewing OP2 within the topic Service Mode in the Systems Operation section. The factory setpoints are: 400 rpm for P11, 90 seconds for P17 and 10 seconds for P18. The setpoints should be correct for the engine application.

NOTE: Engines equipped with prelube pumps may require crank cycle times (setpoint P18) of 30 seconds or more.

* If the setpoints are correct, then go to Step 2.

* If any setpoint is NOT correct, reprogram the setpoints per print 103-1582 Chart. See Setpoint Programming OP5 within the topic Service Mode in the Systems Operation section. Go to Step 2.

2. CHECK FOR CAUSE OF PROBLEM - Disable the fuel solenoid or the governor to prevent the engine from starting but not from cranking. Perform each of the following steps in the order listed until the cause of the problem is found. Turn the ECS to START and allow the engine to crank.

2a. Turn the ECS to OFF/RESET.

* If the engine stops cranking, go to Step 3.

* If the engine continues to crank, go to Step 2b.

2b. Check the SMR output.

* Check the wire on terminal 18 of the relay module for a short to B+. If a short is not found, replace the relay module. See the topic Relay Module Replacement. STOP.

* If the engine continues to crank, go to Step 2c.

2c. Stop the engine. Remove all wires from terminal 25 of TS1 in the generator housing. (For dual starting motors, also remove all wires from terminal 26.) Attempt to start the engine.

* If the engine stops cranking, the starting motor magnetic switch (SMMS) or related wiring is faulty. Troubleshoot the SMMS and the related wiring. See the Main Chassis Wiring Diagram in the Schematics And Wiring Diagram section. STOP.

* If the engine continues to crank, go to Step 2d.

2d. Stop the engine. Remove the positive wire on the pinion solenoid of the starting motor. Attempt to start the engine.

* If the engine stops cranking, wire 052-125 or 125-152 in the engine harness is shorted to battery positive (B+). Troubleshoot the wiring. See the Generator Set Wiring Diagram in the Schematics And Wiring Diagram section. STOP.

* If the engine continues to crank, the starting motor is faulty. Troubleshoot the starting motor. Refer to the Starting Motor and/or Engine Service Manuals. STOP

3. CHECK STARTING MOTOR CYCLING - The engine remains disabled from starting. Turn the ECS to START. The starting motor should cycle on and off according to setpoint P18 (cycle crank time).

* If the starting motor cycles correctly, the problem is not present. STOP.

* If the starting motor remains ON and does not stop, the starting motor is faulty. Troubleshoot the starting motor. Refer to the Starting Motor and/or Engine Service Manuals. STOP

Problem B

No engine shutdown when a shutdown fault occurs.

1. CHECK FOR DIAGNOSED FAULTS - Check the display area of the GSC for a fault indicator that is FLASHING and check for a fault code on the upper display.

NOTE: If the fault alarm indicator is ON CONTINUOUSLY, then the GSC is programmed to override the normal shutdown response and treats the condition as an alarm fault (engine continues to run). This is not a problem. To view the setpoints, see Setpoint Viewing OP2 within the topic Service Mode in the Systems Operation section. To reprogram the setpoints, see Setpoint Programming OP5 within the topic Service Mode in the Systems Operation section.

* If the fault shutdown indicator is FLASHING and the engine remains running, then:

For ETR fuel systems, go to Step 2.

For ETS fuel systems, go to Step 3.

For 3500 engines with electronic governor, go to Step 6.

* If the fault alarm indicator is OFF, the fault shutdown indicator is OFF and a fault exists that should cause the GSC to shutdown the engine, then go to Step 7.

2. ETR SYSTEMS. CHECK FOR CAUSE OF PROBLEM - The engine remains running and the fault shutdown indicator is FLASHING. Perform each of the following steps in the order listed until the cause of the problem is found.

2a. Turn the ECS to OFF/RESET.

* If the engine shuts down, the system is functioning properly. Start the engine again. If the fault shutdown indicator is FLASHING and the engine does not shutdown, replace the GSC. See the topic Generator Set

Control Replacement. STOP.

* If the engine does NOT shutdown, go to Step 2b.

2b. Push the emergency stop push button.

* If the engine continues to run, it is most likely that an unwanted battery positive (B+) voltage is present at terminal 15 of the relay module. Check the related wiring for this unwanted voltage. If no battery voltage is found in the related wiring, then replace the relay module. See the topic Relay Module Replacement.

* If the engine still does NOT shutdown, go to Step 2c.

2c. Remove all wires from terminal 7 of TS1 in the generator housing.

* If the engine shuts down, there is a wiring error or short to battery positive between terminal 7 of TS1 and the relay module. On 3408 and 3412 engines, the auxiliary fuel control relay (AFCR) on the sub-panel could be faulty. Troubleshoot and repair the wiring, see the system schematic in the Schematics And Wiring Diagram section. STOP.

* If the engine does NOT shutdown, go to Step 2d.

2d. Remove both wires from the fuel solenoid.

* If the engine shuts down, wire 850-907 or 907-950 is shorted to battery positive (B+) in the engine harness. Troubleshoot and repair the wiring, see the Generator Set Wiring Diagram in the Schematics And Wiring Diagram section. STOP.

* If the engine does NOT shutdown, the fuel solenoid is stuck or otherwise faulty. Refer to the engine Service Manual to troubleshoot and repair. STOP.

3. ETS SYSTEMS. CHECK SYSTEM VOLTAGE - Shut the engine down, manually if necessary. Turn the ECS to STOP. Measure the DC voltage of the batteries. Voltage should measure from 24.8 to 29.5 volts DC for 24 volt systems or 33.1 to 39.3 volts DC for 32 volt systems.

* If voltage is correct. Go to Step 4.

* If voltage is NOT correct. See the topic CID 168 in the Diagnostic Fault Codes section to check the system voltage.

NOTE: On ETS fuel systems, if the GSC is entirely turned off (the display area is blank), then the GSC is not able to shutdown the engine. Check for wiring errors in the power connections to the GSC open circuit breakers, and for discharged batteries.

4. ETS SYSTEMS. CHECK FOR CAUSE OF PROBLEM - The engine remains shutdown. The ECS remains in the STOP position. Push in the emergency stop push button. Prepare to make the following DC voltage measurements. All measurements are to B- (ground). Attach the black lead of the multimeter to B- (ground). Measure the voltage from B- (ground) to each of the following points in the order listed. Each of the voltages should measure the same as the system voltage noted in Step 3 ± 2.0 DCV.

4a. Voltage across the fuel solenoid terminals.

* If the voltage is correct, the fuel solenoid is stuck or otherwise faulty. Troubleshoot and repair the faulty solenoid, see the Engine Service Manual. STOP.

* If the voltage is NOT correct, go to Step 4b.

4b. Voltage from terminal 7 of TS1 in the generator housing to battery negative (ground).

* If the voltage is correct, there is an open in the engine wire harness. Troubleshoot and repair the engine harness, see the Generator Set Wiring Diagram in the Schematics And Wiring Diagram section. STOP.

* If the voltage is NOT correct, go to Step 4c.

4c. Voltage from terminal 15 of the relay module to battery negative (ground).

* If the voltage is correct, there is an open in the wiring between terminal 15 of the relay module and terminal 7 of TS1. Troubleshoot and repair the wiring, see the Main Chassis Wiring Diagram in the Schematics And Wiring Diagram section. STOP.

* If the voltage is NOT correct, go to Step 4d.

4d. Voltage from terminal 31 of the relay module to battery negative (ground).

* If the voltage is correct, it is most likely that fuse F2 is open (blown). Replace fuse F2. If fuse blows again, go to Step 5.

* If the voltage is NOT correct, there is an open in the wiring between terminal 31 of the relay module and battery positive (B+). Troubleshoot and repair the wiring, see the system schematic in the Schematics And Wiring Diagram section. STOP.

5. TROUBLESHOOT BLOWN FUSE - Remove fuse F2. At the relay module, measure the resistance from terminal 15 to B- (ground). The resistance will measure 5 ohms or less if a short to ground exists.

Remove one component or wire at a time that is in series with terminal 15 until the faulty component or wire is isolated. See the system schematic in the Schematics And Wiring Diagram section. Repair or replace the faulty component or wiring. STOP.

6. 3500 ENGINES WITH ELECTRONIC GOVERNOR. CHECK FOR CAUSE OF PROBLEM - The engine is running with the fault shutdown indicator FLASHING. Remove fuse F6 from the relay module. The engine should shutdown. At the relay module, measure the resistance from terminal 8 to terminal 24. The resistance should measure 5k ohms or greater.

* If the engine shuts down and the resistance is correct, the electronic governor is incorrectly being supplied battery positive (B+). Troubleshoot and repair the related wiring, see system schematic in the Schematics And Wiring Diagram section. STOP.

* If the engine shuts down and the resistance is NOT correct, there is a wiring error or the relay module is faulty. Check the wiring to terminals 8 and 24 of the relay module, see the Main Chassis Wiring Diagram in the Schematics And Wiring Diagram section. Repair any wiring errors. If the wiring is correct, then replace the relay module; see the topic Relay Module Replacement. STOP.

* If the engine continues to run, the rack or electric actuator are stuck in the ON position. Troubleshoot and repair the rack or electric actuator; see the Service Manual for the particular electronic governor. STOP.

For the 2301A Speed Control, see Service Manual SENR4676.

For the 2301A Load Share, see Service Manual SENR3585.

For 524 and 1724 Electrically Powered Governor Systems, see Service Manual SENR6430.

7. Determine the fault that causes the engine to shutdown. Perform the following procedure (1, 2 or 3) that corresponds to the fault.

1. For a fault with the coolant loss sensor that does not shutdown the engine, see the topic CID 111 in the Diagnostic Fault Code section.

2. For a fault with engine overspeed, low oil pressure, or high water temperature that does not shutdown the engine - Make a note of all the engine information showing on the lower display of the GSC. View the related setpoints, see Setpoint Viewing OP2 within the topic Service Mode in the Systems Operation section. Compare the engine information showing on the lower display with the related setpoints.

* If the information showing on the lower display is within the related setpoint, then the GSC is not causing the shutdown. STOP.

* If the information showing on the lower display is beyond the related setpoint, then the GSC is faulty. Replace the GSC; see the topic Generator Set Control Replacement. STOP.

3. For a fault with protective relay that does not shutdown the engine:

NOTE: Not all protective relays cause immediate engine shutdown. Refer to system operation for expected results.

a. Install a multimeter to monitor the DC voltage from contact 23 of the GSC connector to B- (ground). Probe the rear of the harness connector at contact 23 with the 7X-1710 Cable Probes. Do not disconnect the harness from the GSC. With the ECS in OFF/RESET, the voltage should measure 10.5 ± 1.0 DCV.

b. Start and run the engine. Apply a load to the generator which is at least 15% of the rated load. Press the test button on the reverse power relay. The reverse power relay is located on the sub-panel within the switchgear.

c. The engine should shutdown and SP1 should show on the upper display of the GSC. The fault shutdown indicator should be FLASHING.

d. The DC voltage at contact 23 should measure 0 ± 1.0 DCV.

e. If the voltage at contact 23 does not drop to 0 volts, then the reverse power relay is faulty or there is a fault component in the shut-down circuit. Troubleshoot and repair the system, see the system schematic in the Schematics And Wiring Diagram section. STOP.

Problem C

Fault indicators of the remote annunciator or control panel alarm module (that are controlled by the data link) all flash at a rate of once per two seconds (0.5 Hz).

System Schematic For Alarm Module (ALM)

NOTE: The maximum number of modules (Alarm, Remote Annunciator, or Customer Interface Module), that can be connected to the GSC is three. The maximum distance between a module and the GSC is 305 m (1000 ft). If these specifications are not met, the information on the data link can be erratic and cause the indicators on the alarm module to flash. If not in compliance with the specifications, reduce the number of modules and/or shorten the distance to the GSC.

1. CHECK DATA WIRE - Turn the ECS to OFF/RESET. Disconnect the harness connector from the GSC. Measure the resistance of the following circuits in the harness:

a. Check for open. Measure the resistance from terminal 2 of the alarm module to contact 35 of the GSC harness connector. The resistance should measure 5 ohms or less.

b. Check for short. Measure the resistance from contact 35 of the GSC harness connector to both battery positive (B+) and negative (B-) at the relay module. The resistance should measure 5k ohms or greater.

* If all resistance measurements are correct, go to Step 2.

* If one or more of the resistance measurements are NOT correct, then the harness wiring with the incorrect resistance is faulty (open or shorted). Troubleshoot and repair the faulty harness wiring. STOP.

2. MEASURE VOLTAGE AT ALARM MODULE - The ECS remains in the OFF/RESET position. Reconnect the harness connector to the GSC. Make the following voltage measurements.

a. At the alarm module measure the DC voltage from terminal 2 to terminal 7. The voltage will be changing, but it should measure between 1 and 10 DCV.

NOTE: If troubleshooting a remote annunciator, measure the DC voltage (with the 7X-1710 Cable Probes) from contact 35 to contact 31 of the GSC harness connector. Do not disconnect the harness from the GSC. This voltage measurement should agree with the preceding measurement of step a. If the voltages do not agree, the wire is faulty from terminal 2 of the alarm module to terminal 18 of TS1 in the generator housing.

b. Disconnect all wires from terminal 2 of the alarm module. Again measure the DC voltage from terminal 2 to terminal 7 at the alarm module. The voltage should measure 10.5 ± 1.0 DCV.

* If both voltage measurements are correct, replace the alarm module. STOP.

* If both voltage measurements are low, replace the alarm module.

* If the first measurement is low and the second high, replace the GSC. See the topic Generator Set Control Replacement. STOP.

Problem D

Fault shutdown indicator on the GSC flashes at the rate of four to five times per second (4 to 5 Hz). The displays of the GSC may be unintelligible. The GSC does not respond to any position of the engine control switch (ECS).

This is an internal fault of the GSC that can be temporary or permanent. The fault is caused by a component failure in the GSC or by extremely severe electro-magnetic or radio frequency interference. The relays in the relay module are automatically turned off when this fault occurs. The effect of this fault on the engine depends on the type of fuel system.

For engines with 2301A governor, the engine shuts down.

For ETS engines with mechanical governor, the engine runs at rated speed.

1. RESET THE GSC - Cycle circuit breaker 1, momentarily open the circuit breaker then close it, STOP. The GSC should power up with an understandable display and should now respond to the ECS switch.

* If the GSC operates correctly, then the fault is gone. STOP.

* If the GSC does NOT operate correctly and the fault shutdown indicator still flashes at the rate of four to five times per second (4 to 5 Hz), then the GSC is faulty. Replace the GSC, see the topic Generator Set Control Replacement. STOP.

Problem E

0 volts or 0 amps are showing on the display of the GSC for one or more AC phases with the genset running and the circuit breaker closed.

System Schematic For AC Transformer Box (ATB)

Show/hide table

When the engine-generator, or any source to which the engine-generator is synchronized to, is operating, voltages up to 600V are present in the control panel.

For AC voltage problems begin troubleshooting at Step 1.

For AC current problems begin troubleshooting at Step 4.

1. CHECK FUSES - Check the three fuses on the AC transformer box (ATB). The fuses should not be blown.

* If the fuses are OK, then go to Step 2.

* If one or more of the fuses are blown, then check for a shorted component or wiring error. Troubleshoot and repair the fault, see the system schematics in the Schematics And Wiring Diagram section. STOP.

2. CHECK GENERATOR OUTPUT - With the engine running and the circuit breaker open or load removed, measure the voltage between all three fuses on the ATB. The line to line voltage should measure correctly for all three phases.

* If the voltages are correct and the problem remains, go to Step 3.

* If one or more of the voltages are NOT correct, the wiring or connections are faulty. Check for wiring errors between the ATB and the generator buss, see the system schematic in the Schematics And Wiring Diagram section. Also check the electrical connections at the ATB terminal, see the topic Electrical Connector Inspection. STOP.

3. Stop the engine. Check ATB and GSC Connectors. Check the harness connector and crimp terminals of the ATB. Check the GSC harness connector. See the topic Electrical Connection Inspection. Also check for one or more broken wires between the ATB and the GSC. See the Main Chassis Wiring Diagram in the Schematics And Wiring Diagram section.

* If the fault concerns AC voltage and the fault remains, then it is unlikely that the GSC is faulty. Replace the ATB and If the problem still persists replace the GSC. STOP.

* If the fault concerns AC current and the fault remains, then go to Step 4.

4. CHECK CURRENT TRANSFORMERS - Stop the engine. Make sure that the shorting screws on the shorting terminal block are removed. At terminals 51, 52 and 53 of the ATB, disconnect only the wires that lead away from the ATB. These disconnected wires go to the current transformers (CT). Measure the resistance from terminal 50 to each of the disconnected wires. The resistance should measure less than 5 ohms.

* If one or more of the resistance measurements are NOT correct, then a current transformer or related wire is open. Check for an open CT or wiring, see the system schematic in the Schematics And Wiring Diagram section. STOP.

5. CHECK ATB - Stop the engine.

a. Remove the harness connector from the GSC. At the GSC harness connector, measure the resistance from contact 4 to contact 16, contact 5 to contact 16, and contact 6 to contact 16. Allow the measurement to stabilize. Each of the three resistances should measure 120 ± 20 ohms.

* The wires disconnected in Step 4 on terminals 61, 51, 52, & 53 remain disconnected. The only wires connected to these terminals should lead into the ATB. At the terminal strip of the ATB measure the resistance from terminal 51 to 50, from terminal 52 to 50, and from terminal 53 to 50. All resistances should measure less than 1 ohm.

* If all resistances are correct, then the ATB checks good. The fault is in the GSC or the GSC harness connector. Check the GSC harness connector, see system schematics in the Schematics And Wiring Diagram section. If the connector checks good and the fault remains, then replace the GSC. See the topic Generator Set Control Replacement. STOP.

* If one or more of the resistance measurements at the GSC harness connector (step a) are NOT correct, then the ATB or the related wiring is faulty. Check for an open or short in the wiring from the GSC harness connector to the ATB harness connector, see the Main Chassis Wiring Diagram in the Schematics And Wiring Diagram section. Check the electrical connections at the GSC and ATB harness connectors and at the ATB terminal strip, see the topic Electrical Connector Inspection. Repair or replace the wiring as necessary. If the fault is not found, replace the GSC. STOP.

* If one or more of the resistance measurements at the ATB terminal strip (step b) are NOT correct, then the ATB is faulty. Replace the ATB. STOP.

Problem F

The AC voltage and/or current values on the GSC are inaccurate.

NOTE: For the system schematic see the preceding Problem E.

Check setpoints P20 (full scale voltage) and P21 (full scale current). See Setpoint Viewing - OP2 within the topic Service Mode. Typical factory setpoints are: 700V for P20 and 600A for P21. The setpoints should be correct for the genset application.

If only the voltage is inaccurate, check the AC voltage range jumper for correct installation. The jumper should be installed for systems with a full scale AC voltage input of 700 volts. The jumper should not be installed for systems with 150 volts full scale AC inputs or for any unit with external potential transformers. For information regarding the installation of the jumper, see the topic AC voltage Range Selection.

Check the AC calibration, see AC Calibration OP10 within the topic Service Mode in the Systems Operation section.

If the preceding checks do not correct the inaccuracy and the meters used for comparison are known to be highly reliable, then replace the ATB. If the fault remains, replace the GSC. See the topic Generator Set Control Replacement.

Electrical Connector Inspection

Many of the troubleshooting procedures in this Testing And Adjusting section require the inspection of electrical connectors and crimp terminals. Do the following steps to test an electrical connector or crimp terminal. If a faulty connection is found, repair the connection. Then return to the original troubleshooting procedures and check to see if the original fault is resolved and/or continue with the original troubleshooting procedure.

NOTE: Avoid unnecessary disconnecting and connecting of connector halves in order to troubleshoot system faults. This practice can cause the connector contacts within the connector to wear out prematurely.

1. Check Connector Hex Screw. Make sure that the 40 pin harness connector on the rear of the GSC is aligned and seated properly and that the hex screw is tight. Any unused locations in the 40 pin harness connector should be plugged to keep out dirt, water and other contaminates.

2. Pull Test Each Wire. Each connector contact and wire in the various harness connectors should easily withstand 10 pounds of pull and remain in the connector body. This test checks to see if the wire in each connector contact was crimped properly, and also that the connector contact was inserted into the connector body completely. Repair as needed. When replacing connector contacts, use only the 1U-5804 Crimp Tool and make sure that the connector contact and tool are matched to the wire gauge. Connector contacts should always be crimped onto the wire, never soldered.

Also do the pull test for the pre-insulated crimp terminals on the terminal strips. Repair as needed. When replacing crimp terminals, use the proper crimping tool and techniques for the type and brand of crimp terminal. Use an appropriately sized terminal for the wire gage. If desired, crimp-on spade and ring terminals may be soldered to the wire for an improved electrical connection.

3. Visually Inspect Wiring. Look for worn or abraded wires. Check for pinched or damaged harnesses.

4. Visually Inspect Connectors And Crimp Terminals. Verify that connector contacts within the connectors are not corroded or damaged. Verify proper alignment and location of connector contacts within the connector. Verify that the two connector halves are seated and locked together.

Check all crimp terminals for corrosion and damage. When wiggling each wire on a crimp terminal, the ends of the bare wires on the open end of the terminal barrel should be tight and not move. Check tightness of terminal strip screws also. Repair as needed.

5. Check Individual Connector Contacts. This is especially important for intermittent problems. Using a new connector contact, insert it into each of mating connector contacts. Check for a snug fit between the mating connector contacts. Repeat this procedure for the other connector half, using a new connector contact of the correct type.

Alarm Module (ALM) Adjustment

Alarm Module
(1) Plug.

For all alarm applications, the low DC volts alarm setpoint is adjusted by a potentiometer located under the access plug (1) on the rear of the module. The adjustment range is 8 to 38 volts. The alarm setpoint is factory set at 24 DCV.

Adjustment Procedure

1. Access the rear of the Alarm Module. (It is not necessary to remove the ALM unless removal is needed for access.) Do not disconnect terminal wires unless otherwise noted.

2. Remove the plug (1) to access the adjustment potentiometer. Because moisture can enter the ALM, remove the plug in a dry environment. If relative humidity exceeds 60%, remove the plug in an air conditioned area.

3. Disconnect the wires on terminals 1 and 7. Secure them so they can't touch each other, a ground or other electrical connection.

4. Connect a variable DC power supply to the Alarm Module (positive to terminal 1, negative to terminal 7). Set the power supply voltage to the desired low DCV alarm setpoint (between 8 and 38 volts).

5. Turn the adjustment pot fully clockwise.

6. After a minute, the indicator on the ALM for low battery voltage flashes. Press the alarm silence switch. The low battery voltage indicator should now remain ON continuously.

7. Turn the adjustment potentiometer counterclockwise slowly until the low battery voltage indicator goes OFF.

8. Replace the plug.

9. Disconnect the variable PC power supply and reconnect the wires to terminals 1 and 7.

Annunciator and Flasher Modules

(1) Flasher module. (2) Annunciator module.

The annunciator and flasher modules work together to create an alarm and lamp alert condition. When an alarm condition occurs, an alarm latch is set in the annunciator, which creates a flashing signal. At this time, the horn driver relay is energized to sound the alarm horn. Once the signal is acknowledged, a second latch provides an electrical path to steadily illuminate the alarm lamp until the condition is rectified. When the condition no longer exists, both latches are reset.

Magnetic Pickup (MPU) Adjustment

Magnetic Pickup (MPU)
(1) Air gap. (2) Locknut.

The Magnetic Pickup adjustment can be completed following these steps:

1. Remove the magnetic pickup from the flywheel housing. Remove all debris from the tip of the magnetic pickup, and align a ring gear tooth directly in the center of the threaded opening.

2. By hand, screw the pickup into the hole until the end of the pickup just makes contact with the gear tooth.

3. Back the pickup out 3/4 turn (270° counterclockwise).

4. Tighten locknut (2) to 25± 5 N·m (18 ± 4 lb ft).

NOTE: Do not allow the pickup to turn as the locknut is tightened.

Charging System Test

NOTE: The Charging System Test procedures discussed on this page are for gensets equipped with alternators.

Test Procedure

Put the multimeter positive (+) lead on the BAT terminal of the alternator. Put the negative (-) lead on the ground terminal or the frame of the alternator. Put a clamp-on ammeter around the alternator's positive output wire.

1. If the battery is already low in charge, skip Step 2 and go to Step 3. If not, disable the fuel solenoid or governor, shutting the fuel off and preventing the engine from starting. DO NOT disable the starting motor. Turn the engine control switch to OFF/RESET. To activate the starting motor, temporarily place a jumper from the B+ terminal to the R-18 terminal at the relay module terminal strip. Crank the engine for 30 seconds. Wait two minutes to cool the starting motor. Crank the engine again for 30 seconds.

2. First, enable the fuel solenoid or governor disabled in Step 2. Then, start the engine and run at full throttle. If necessary, jump-start the engine or charge the batteries to start the engine.

3. Immediately check the output current of the alternator. For correct operation, this initial charging current is equal to-or slightly greater than-the full rated output current of the alternator. The specified full-rated output current of some alternators is:

100-5047 (24V) ... 50A

3E-7577 (24V) ... 75A

3E-7578 (24V) ... 50A

4N-3986 (24V) ... 60A

6N-9294 (24V) ... 35A

6T-1395 (24V) ... 35A

7T-2095 (24V) ... 35A

9W-3043 (24V) ... 55A

4N-3987 (32V) ... 60A

4. At full throttle, the specified alternator output voltage-after ten minutes-should be:

5. With accessories turned OFF, the charging current should decrease to less than 10 amps (depending again upon battery and alternator capacities).

Magnetic Switch Test (24V)

The Starting Motor Magnetic Switch (SMMS) for 24V systems is mounted in a small enclosure on the engine. Two switches are employed in dual starting motor systems, one for each starting motor.

Test Procedure

Disconnect the jumper wire between terminals 4 and 5 in the switchgear. Measure the resistance between terminal 5 and terminal 2. The resistance should be:

26-33 ohms-single starter system 13-17 ohms-dual starter systems.

If the resistance is NOT correct, replace the defective magnetic switch. If resistance is correct, go to Step 2.

1. Disconnect the cable from the pinion solenoid to the starting motor. Disconnect from both motors of a dual system.

2. Connect a DC voltmeter. The positive goes to terminal 24, the negative to terminal 25 of TS1 in the generator housing. To test the second magnetic switch a dual starting motor system, connect the negative to terminal 26.

3. Connect a jumper wire from terminal 1 to terminal 5 of TS1. The correct measurement changes from ± 24 DCV to ± 2 DCV. Disconnect this wire immediately after the voltage is measured. DO NOT leave it connected for more than ten seconds.

If the voltage is greater than 2.0 DCV, replace the magnetic switch. If the switch passes the requirements of Step 1 and 4, it is functioning correctly.

Finally, reconnect the wires and cables that were removed in this procedure.

Circuit Breaker

Test points on the front panel provide convenient access for monitoring probes. Setpoints for both the Long-Time Delay and the Instantaneous Delay selectors can be altered from the factory settings.

For further information about circuit breaker testing and adjustment, see the breaker manufacturer's manual included with Caterpillar Switchgear.

Protective Relay Adjustment

Protective relays have all been adjusted to operating standards at the factory, but each relay can be readjusted in the field when circumstances dictate. Refer to information specific to each relay in the documentation packet shipped with each switchgear.

EMCP II PWM Sensor Adjustment

System Schematic For Engine Oil Pressure Sensor (EOPS)

System Schematic For Engine Coolant Temperature Sensor (ECTS)

Pulse Width Modulated (PWM) Signal

In addition to CID 100 and CID 110 troubleshooting (see Diagnostic Fault Code chart), you can measure the frequency and duty cycle of sensor signals for accuracy.

The Oil Pressure Sensor and the Coolant Temperature Sensor are pulse width (PWM) sensors. They produce a digital signal in which the duty cycle varies as conditions change. Meanwhile, the frequency remains constant.

Test Procedure

This procedure requires the measurement of the frequency and duty cycle of the sensor signal. Use the 9U-7330 Digital Multimeter for measuring frequency and duty cycle. To measure frequency, turn the rotary switch to AC volts and press the HZ button once. To measure duty cycle, turn the rotary switch to AC volts and press the HZ button twice.

NOTE: The 6V-7070 Digital Multimeter does not measure frequency or duty cycle. However, the DC voltages are listed in the Sensor Specifications chart as an alternative to measuring the frequency and duty cycle. The 6V-7070 Digital Multimeter can be used for DC voltage measurements.

1. Locate the suspect sensor. Identify the sensor wires and connector contacts; see the preceding System Schematic. DO NOT DISCONNECT ANY HARNESS CONNECTORS AT THIS TIME. Use the 7X-1710 Cable Probe (Spoons) to make measurements by probing through the back of the harness connectors.

2. CHECK SENSOR SUPPLY VOLTAGE - Turn the ECS to OFF/RESET and then to STOP. Measure the sensor supply DC voltage at the sensor connector (from contact A to contact B on the sensor connector). The voltage should measure from 7.5 to 8.5 DCV.

* OK; the voltage is from 7.5 to 8.5 DCV. Go to Step 3.

* NOT OK; the voltage is equal to battery positive. The sensor supply is shorted to battery positive in the engine harness. Troubleshoot and repair the engine harness. STOP.

* NOT OK; the voltage is not from 7.5 to 8.5 DCV and is not equal to battery positive. Observe the GSC display.

a. If a CID 269 fault code is active, go to that procedure in the Diagnostic Fault Troubleshooting section. STOP.

b. If a CID 269 fault code is NOT active, then the harness is faulty. Troubleshoot and repair the harness. STOP.

3. CHECK SENSOR SIGNAL - The ECS remains in the STOP position. Measure the frequency and duty cycle of the signal at the sensor connector (from contact C to contact B of the sensor connector). Make a note of the measurements. The measured frequency and duty cycle should agree with the values listed in the Sensor Specifications chart.

* OK; the measurements agree with the values listed in the Sensor Specifications chart. The sensor is functioning correctly. Go to Step 4.

* NOT OK; the measurements DO NOT agree with the values listed in the Sensor Specifications chart. Go to Step 5.

4. CHECK ENGINE HARNESS SIGNAL - Measure the frequency and duty cycle of the signal at the GSC harness connector. For the oil pressure signal, measure from contact 8 to contact 31. For the coolant temperature signal, measure from contact 7 to contact 31. The measured frequency and duty cycle should agree with the values measured in Step 3.

* OK; the frequency and duty cycle are the same as measured in Step 3. The sensor and harness are functioning correctly.

a. If sensor fault codes are still active, the GSC is faulty. Replace the GSC, see the topic Generator Set Control Replacement. STOP.

b. If sensor fault codes are NOT active, check the connectors and wiring. See the topic Electrical Connector Inspection. STOP.

* NOT OK; the frequency or the duty cycle are NOT the same as measured in Step 3. The harness is defective. Troubleshoot and repair the engine harness. STOP.

5. CHECK ENGINE HARNESS - Disconnect the engine harness from the sensor. Disconnect the GSC from the harness. Check the harness for an open circuit (greater than 5 ohms). Check the signal wire for a short (5k ohms or less) to battery positive, battery negative and sensor supply.

* OK; all resistance measurements are correct. Replace the sensor. STOP.

* NOT OK; one or more resistance measurements are NOT correct. Troubleshoot and repair the engine harness. STOP.

AC Transformer Box Replacement

AC Transformer Box (ATB)

The AC Transformer Box is located on the sub-panel in the lower half of the switchgear. To replace the ATB, follow these procedures:

1. Shutdown the engine. Remove the positive lead wire from the battery.

2. Make sure that each wire at the terminal strip of the ATB is marked the respective terminal point. (During reassembly these wires must be reattached to the correct terminal.) Remove all external wires from the terminal strip.

3. Disconnect the ATB connector from the harness connector.

4. Remove all mounting nuts/screws that fasten the ATB to the sub-panel. Remove the ATB.

5. Place the new ATB in the sub-panel. Install and tighten the mounting nuts/screws.

6. Reconnect the harness connector to the ATB. Reconnect all the wires to the terminal strip that were removed. Reconnect the positive lead wire to the battery.

7. Program the bar code (calibration value) for the voltmeter/ammeter into the GSC. (See 5.a.1.)

8. If the genset is operating in parallel with another genset, reprogram the AC calibration to make the voltmeter values match.

Generator Set Control Replacement

Replacement Procedure

1. The new GSC must be reprogrammed after it is installed. If the GSC being replaced is functional, then make a note of the hourmeter value, all engine setpoints and any spare inputs/outputs that are programmed. See the topic Setpoint Viewing in the Service Mode Section.

2. Shut down the engine. Remove the positive lead wire from the battery.

3. Remove the harness connector from the GSC. A 4 mm hex wrench is required to turn the fastening screw.

4. Make sure that all wires at the terminal strips of the relay module are marked with the respective termination point. During reassembly these wires must be reattached to the correct terminal. Remove all wires from the terminals and posts of the relay module.

5. Remove the six nuts that fasten the GSC to the instrument door. Remove the GSC.

6. Place the new GSC in the instrument door. Install and tighten the six nuts.

7. Reconnect the harness connector to the GSC. Reconnect all the wires to the terminals of the relay module that were removed. Reconnect the positive lead wire to the battery. If necessary, see the Main Chassis Wiring Diagram in the Schematics And Wiring Diagrams section.

8. Reprogram the setpoints, the spare inputs/outputs, the hourmeter, the voltmeter/ammeter and the AC calibration; see the related topics in the Service Mode section. Use the values from the original GSC. If the original values are not available, reprogram using the setpoints of the 103-1582 Chart.

Relay Module Replacement

Relay Module Replacement (Rear of GSC)
(1) Relay Module. (2) Screws. (3) Tape. (4) Desiccant package. (5) O-ring seal. (6) Cable connector.

Replacement Procedure

1. Remove the positive lead wire from the battery.

2. Make sure that all wires at the terminal strips of relay module (1) are marked with the respective termination point. During reassembly these wires must be reattached to the correct terminal. Remove all wires from the terminals and posts of relay module (1).

3. Remove ten screws (2) that fasten relay module (1) to the GSC.

4. Be aware that O-ring seal (5) exists. Partially separate relay module (1) from the GSC. Carefully disconnect cable clamp and cable connector (6) from relay module (1).

5. Replace desiccant package (4) with the new desiccant package and tape that is included with the replacement relay module. Attach the new desiccant package in the same manner as the one removed.

NOTE: Do not remove the new desiccant package from the protective container until immediately before it is installed into the GSC. Installing the replacement relay module should take approximately 20 minutes. Longer periods of time will cause the desiccant package to become saturated with moisture, particularly if in a humid environment.

6. Install new O-ring seal (5) in the groove of relay module (1). (For removal and installation jobs, reuse the existing O-ring). Make sure O-ring seal (5) is seated properly. Align and reconnect cable connector (6) to relay module (1) and install the cable clamp.

7. Place relay module (1) on the GSC. Check that O-ring (5) remains seated. Align the screw holes of relay module (1) and the GSC. Install and tighten ten screws (2).

8. Reconnect all the wires to the terminals of the relay module that were removed. Reconnect the positive lead wire to the battery. If necessary, see the Main Chassis Wiring Diagram in the Schematics And Wiring Diagrams section.