Electronic Modular Control Panel II+ (EMCP II+) for EUI Engines Caterpillar

CID 168 FMI 4 Electrical System Voltage Below Normal - Test

Usage:

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Illustration 1	g00650545

The EMCP II+ monitors the battery voltage in order to protect the EMCP II+ from a battery problem or from a charging problem. The battery voltage is received from the engine electronic control module (ECM) by the CAT data link. If you receive an CID 168 E fault, see the Troubleshooting, " 3500B Generator Set Engines Troubleshooting". The GSC+ treats a CID 168 fault as an alarm fault. The threshold for a CID 168 FMI 04 fault for battery voltage is less than 18 DCV for 24 volt system and for a 32 volt system.

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Table 1
Possible Causes for CID 168 Faults
Location that the Fault is Displayed On	Diagnostic Code	Battery Voltage Thresholds (24 Volt System)	Battery Voltage Thresholds (32 Volt Systems)
Engine ECM	CID 168 E 00	The engine is running and the battery voltage is greater than 32 DCV more than two seconds.	-
Engine ECM	CID 168 E 01	The engine is not running and the battery voltage is less than 9 DCV for more than two seconds.	-
Engine ECM	CID 168 E 02	The engine is not running and the battery voltage is less than 9 DCV for a period of .07 seconds and then returns to 9 DCV or above. The other possible cause of the fault is the battery voltage is was less than 9 DCV three times in seven seconds.
GSC+	CID 168 FMI 03	-	Regardless of engine status, the battery voltage is greater than the P007 limit.
GSC+	CID 168 FMI 04	-	Regardless of the engine status, the battery voltage is less than 18 DCV.

The setpoint for the system voltage (P007) specifies the battery voltage.

24 - 24 Volt System

32 - 32 Volt System

Note:

Note: The GSC+ does not receive battery power when the ECS is in the OFF/RESET position. When contact 6 is connected to one of the contacts (8, 9, 10), the GSC+ receives battery power when the ECS is in the OFF/RESET position.

Initial Procedure.
Make sure that the CID 168 FMI 04 is shown on the display.
1. Enter service mode.
1. Turn the ECS to the STOP position.
1. Program setpoint P023 to 0. This programs the GSC+ for an MUI engine. This eliminates the engine electronic control module (ECM) as a possibility of the fault. For more information, see System Operation, "Protective Relaying Programming OP5-1".
1. Turn the ECS to the OFF/RESET position. Disconnect the jumper wire on the ECS that is between pin 6 and pin 9. Not all generators will have a jumper wire between pin 6 and pin 9. Proceed to Step 2.

Check the system's voltage.
1. Turn the ECS to the STOP.
1. Measure the voltage across the battery terminals.
  Expected Result: For a 24 volt system, the voltage should be between 24.8 DCV and 29.5 DCV. For 32 volt system, the voltage should be between 33.1 DCV and 39.3 DCV.
  Results:
  - OK: For a 24 volt system, the voltage should be from 24.8 DCV to 29.5 DCV. For a 32 volt system, the voltage should be from 33.1 DCV to 39.3 DCV. Proceed to Step 3.
  - NOT OK: For 24 volt systems, the voltage is not between 24.8 DCV to 29.5 DCV. For a 32 volt system, the voltage is not between 33.1 DCV to 39.3 DCV. The fault is in the charging system. Proceed to Testing and Adjusting, "Charging System - Test". STOP.

Compare the voltage between TS1-1 and the battery voltage.
1. Turn the ECS to the STOP position.
1. Measure the battery voltage across the terminals. Take note of the battery voltage.
1. Measure the voltage between TS1-1 and TS1-30. Take note of the voltage.
1. Compare the voltage from Step 3.b with the voltage that was noted in Step 3.c.
  Expected Result: The voltages that are measured in Step 3.b and Step 3.c are within 2.0 DCV of each other.
  Results:
  - OK: The voltages that are measured in Step 3.b and Step 3.c are within 2.0 DCV of each other. Proceed to Step 4.
  - NOT OK: The voltages that are measured in Step 3.b and Step 3.c are not within 2.0 DCV of each other. The wiring harness is not correct. Repair the wiring harness or replace the wiring harness. Proceed to Step 8.

Compare the voltage between the TS1-1 and the ECS.
1. Turn the ECS to the STOP position.
1. Measure the voltage between TS1-1 and TS1-30. Take note of the voltage.
1. Measure the voltage at terminal 6 on the ECS. Take note of the voltage.
1. Compare the measured voltage from Step 4.b with the voltage that was measured in Step 4.c.
  Expected Result: The voltages that are measured in Step 4.b and Step 4.c are within 2.0 DCV of each other.
  Results:
  - OK: The voltages that are measured in Step 4.b and Step 4.c are within 2.0 DCV of each other. Proceed to Step 5.
  - NOT OK: The voltages that are measured in Step 4.b and Step 4.c are not within 2.0 DCV of each other. The wiring harness is not correct. Repair the wiring harness or replace the wiring harness. Proceed to Step 8.

Check the continuity of the ECS.

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Table 2
Engine Control Switch (ECS) ⁽¹⁾ ⁽²⁾
Terminal	OFF/RESET	AUTO	MANUAL	STOP
7	X	O	O	O
8	O	X	O	O
9	O	O	X	O
10	O	O	O	X

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^( 1 )	X = Less than 5 Ohms resistance from this terminal to terminal 6 (ECS).
^( 2 )	O = Greater than 5000 Ohms resistance from this terminal to terminal 6 (ECS).

Disconnect the jumper from 6 to jumper 9 from the ECS.

Place the ECS in the OFF/RESET.

Place the one lead on terminal 6 of the ECS.

Measure the resistance from terminal 6 to each of the terminals ( 7, 8, 9, and 10).

Use the same procedure for each switch position.

Compare the measured resistances with Table 2.
Expected Result: The measured resistances match Table 2.
Results:
- OK: The measured resistances match Table 2. The ECS is not faulty. Proceed to Step 6.
- NOT OK: The measured resistances match Table 2. The ECS is faulty. Replace the ECS. Reinstall the jumper wire. Proceed to Step 8.

Compare the voltage between RM-1 and the ECS.
1. Turn the ECS to the STOP position.
1. Check the voltage between RM- 1 and RM-28. Take note of the voltage.
1. Check the voltage on contact 10 of the ECS. Take note of the voltage.
1. Compare the voltage between Step 6.b and Step 6.c.
  Expected Result: The voltages that were measured in Step 6.b and Step 6.c are within 2.0 DCV of each other.
  Results:
  OK: The voltages that were measured in Step 6.b and Step 6.c are within 2.0 DCV of each other. The harness is correct. Proceed to Step 7.
  NOT OK: The voltages that were measured in Step 6.b and Step 6.c are not equal ± 2.0 DCV. The wiring harness is faulty. Repair the harness or replace the harness. Proceed to Step 8.

Compare the voltage between RM-1 and the lower display.
1. Turn the ECS to the STOP position.
1. Check the voltage between RM- 1 and RM-28. Take note of the voltage.
1. Check the voltage that is shown on the lower display. Take note of the voltage.
1. Compare the voltage between Step 7.b and Step 7.c.
  Expected Result: The voltages that were measured in Step 7.b and Step 7.c are within 2.0 DCV of each other.
  Results:
  OK: The voltages that were measured in Step 7.b and Step 7.c are within 2.0 DCV of each other. The fault is probably an intermittent fault which is caused by a faulty connector. Inspect the electrical connectors. See Testing and Adjusting, "Electrical Connector - Inspect". If the faulty connector can not be found, repeat this test procedure. If the fault still remains, replace the GSC+. STOP.
  NOT OK: The voltages that were measured in Step 7.b and Step 7.c are not equal ± 2.0 DCV. The GSC+ is faulty. Replace the GSC+. STOP.

Reprogram the GSC+.
1. Turn the ECS to the STOP position.
1. Program the setpoint P023 to 2 (EUI). See System Operation, "Engine Generator Programming OP5-0".
1. Turn the ECS to the OFF/RESET position. Disconnect the jumper wire on the ECS that is between pin 6 and pin 9. Not all generators will have a jumper wire between pin 6 and pin 9.
1. Verify that the diagnostic code is no longer present.
1. Replace the jumper between pin 6 and pin 9. Not all generators will have a jumper wire between pin 6 and pin 9. STOP.