Usage:
How To Use Tests
Systems Operation
This area is used to describe subsystem component operation and other pertinent details for troubleshooting.
Control or Sensor Signals
The input and/or output signals are discussed in this area. Generally, each signal is discussed with specifications.
Control Diagnostics
Any control diagnostics which directly relate to the component are briefly discussed. Engine or control response due to a diagnostic code may also be discussed.
NOTE: There are two basic wiring arrangements used on G3600 engines. The early engines used hard conduit on the engine and the engine mounted junction box terminals were labeled from 101 to 458. The later engines used individual flexible stainless steel harnesses and the junction box terminals were labeled from 610 to 958. The later version has been upgraded over time to include the Caterpillar Ignition System (CIS), Detonation Mixing Control (DMC), and the Hydrax actuators. The harnesses and junction box termination labels have remained essentially the same with necessary hardware additions and deletions. The schematics in this publication show only the later version terminal points. For the early versions reference the Electrical Schematics for termination points.
Diagnostic Codes
Inspecting Electrical Connectors
Test Procedure 1
Many of the System Troubleshooting Procedures in this manual will recommend checking a specific electrical connector. The following procedure will assist in the examination of the connector to determine if it is the cause of the problem. If a problem is found in the electrical connector or connection, repair it if possible. If it cannot be repaired, replace the faulty connector or wiring harness.
DO NOT cut the Deutsch connector wires if the connector must be replaced, The Deutsch Style connectors are repairable without the need to cut the wires. New pins and sockets can be inserted with a crimp tool.
NOTE: Wiggle the wires while the engine is running to reveal any intermittent diagnostic codes.
NOTE: Clean electrical connections with an alcohol based cleaner when any connector is unmated in a dirt environment.
NOTE: Turn the Mode Control Switch (MCS) to the OFF/RESET position and open the fuse breaker in the ESS panel before doing wiring checks or disconnecting any harnesses.
Deutsch Connectors
Functional Test
DDT Troubleshooting
System Operation
The Digital Diagnostic Tool (DDT) provides status information for the Engine Supervisory System (ESS). The DDT communicates directly with the Engine Control Module (ECM) over the CAT Data Link. The DDT is the interface used to display ESS Control System status information of engine operating conditions such as engine speed, detonation, inlet manifold pressure, and ignition timing. The DDT is also used for programming the ESS Control System to match performance requirements.
The DDT operates on Battery voltage. The battery voltage is supplied to the DDT at the same time voltage is applied to the ESS Control Module.
Two communication wires between the DDT and the ESS panel carry the information.
The DDT Service Tool can be connected to the ESS System at the Service Tool Connector on either The Engine Mounted Terminal Box or the ESS Panel.
NOTE: Do not connect more than one DDT Service Tool at a time.
Figure 1: DDT Diagram
Figure 2: DDT Communications Components Using 7X-1400 Tool Gp.
Figure 3: DDT Wiring Schematic
Diagnostic Codes
Functional Test
SCM Speed Sensor
System Operation
The SCM Engine Speed Sensor (MPU) is a passive magnetic pickup sensor that provides engine speed to the SCM.
The Engine Speed Sensor must be installed with an air gap of one half to three fourths counterclockwise turn from full bottom position. A properly adjusted air gap will prevent nuisance diagnostics.
NOTE: The sensor is shared with the Timing Control Module (TCM) and DMC where applicable.
The sensor outputs a sinusoidal waveform created as the flywheel ring gear teeth pass beneath the pickup. The frequency of the signal is proportional to the speed of the engine. The signal can be interpreted as engine speed (rpm) equals frequency (Hz) multiplied by 60 then divided by the number of teeth (255).
rpm=(Hz) X 60 / (255)
The frequency of the signal can be measured using a voltmeter with an AC frequency mode or an oscilloscope.
Figure 2: SCM Speed Sensor Schematic
Figure 3: Speed Sensor Output Table
Diagnostic Codes
Functional Test
Oil Pressure/Temperature Module
System Operation
The SCM monitors the oil pressure and oil temperature to provide basic engine protection.
The Oil Pressure/Temperature Module (or Transducer Module) receives engine oil pressure sensor and oil temperature sensor values and relays the information to the SCM.
The sensor module sends the engine oil temperature and pressure information to the SCM in a serial communications message.
Figure 1: Oil Pressure/Temperature Module Diagram
Figure 2: Oil Pressure/Temperature Module Schematic
Refer to the Electrical Schematic for the terminations.
Diagnostic Codes
Functional Test
Mode Control Switch (MCS)
System Operation
The Status Control Module (SCM) uses the Mode Control Switch (MCS) to control the starting and stopping functions for the engine.
Placing the Mode Control Switch (MCS) to the OFF/RESET position is used to clear and reset diagnostic fault codes.
The SCM input is connected to ground by the MCS to determine the MCS switch position.
This diagnostic code will be active if there is an open or short from the Mode Control Switch (MCS) to the SCM. At least one input (AUTO, START, STOP or OFF/RESET) must be connected to -Battery.
Figure 2: Mode Control Switch Schematic
Refer to the Electrical Schematic for the terminations.
Diagnostic Codes
Functional Test
SCM Memory/Program Mismatch
System Operation
The programmable set point information is stored and used in the control strategy of the SCM. The set points programmed into the SCM are factory set. The set points can be changed for an application specific configuration or when a special (usually Overcrank or cycle crank) is needed.
Diagnostic Codes
Functional Test
Engine Shutdown
System Operation
The diagnostic code indicates that the engine was shut down by an external engine related component or condition and the SCM did not receive a shutdown command before the engine speed reached 50 rpm. The most common conditions are described below. Fuel supply is turned OFF. Airflow to the engine inlet air system is restricted. Ignition system shutdown is active.
Figure 1: Status Control Module
Diagnostic Codes
SCM Voltage Supply
System Operation
The SCM continuously monitors the system battery voltage. The SCM displays the information and monitors for insufficient battery voltage.
Figure 1: Status Control Module
Diagnostic Code
Functional Test
SCM Temperature Probe
System Operation
The sensor is a resistive type sensor. The Oil Temperature Sensor probe monitors oil temperature and is used to protect the engine from high oil temperature operation.
Figure 2: Oil Pressure/Temperature Module Schematic
Diagnostic Codes
Functional Test
Figure 3: Temperature Sensor Resistance Table
SCM Oil Pressure Probe
System Operation
The sensor is a resistive type sensor. The Oil Temperature Sensor probe monitors oil temperature and is used to protect the engine from high oil temperature operation.
Figure 2: Oil Pressure/Temperature Module Schematic
Diagnostic Codes
Functional Test
Battery Voltage Low
System Operation
The ESS System Panel continuously monitors the System Battery Voltage with the CMS Module. The ECM uses the information to protect the engine from operation with insufficient battery voltage. The ECM can be selected (via the Personality Module) to either generate a Shutdown, generate an Alarm, or not monitor the System Battery Voltage at all.
Although this sensor (or data) is read by the CMS Module, the sensor data output is relayed via the CAT Data Link to the ECM and processed. The ECM performs the diagnostics associated with this data.
Control Diagnostics
168-01 (Not Flashing) Battery Voltage Low Alarm indicates the system battery voltage has dropped below the Low Battery Voltage Alarm Level. Std=20 VDC
168-01 (Flashing) Battery Voltage Low Shutdown Level indicates the battery voltage is at the minimum programmed parameter for a certain period of time. The ECM will display a flashing diagnostic code and the engine will shut down. Std= 18 VDC
Figure 2: Battery Schematic
Diagnostic Codes
Functional Test
Gas Shutoff Valve (GSOV) Failure
System Operation
The Gas Shutoff Valve is an electrically actuated solenoid valve that controls the fuel supply to the engine. This valve is used to interrupt the fuel flow to the engine and is the Primary means of shutting down the engine. The Status Control Module (SCM) uses an internal fuel control relay (FCR) to energize the Gas Shutoff Valve. The gas control valve is energized (opened) by sending +battery to its solenoid. The valve is de-energized (closed) by open circuiting the solenoid.
Control Diagnostics
017-12 Gas Shutoff Valve Failure
Once the shutdown has been initiated (the Gas Shutoff Valve should now be closed) the ECM momentarily opens the fuel control valve when Fuel Manifold pressure drops to 1 kPa. If the fuel pressure exceeds 30.0 kPa (4.35 psi) the fuel control valve is open, the ECM generates the 017-12 Diagnostic Fault Code.
Figure 1: Gas Shutoff Valve Diagram
Figure 2: Gas Shutoff Valve Schematic
Diagnostic Codes
Functional Test
Fuel Temperature Sensor
System Operation
The Fuel Temperature Sensor provides the temperature of the fuel in the fuel manifold to the Engine Control Module (ECM). The ECM monitors the fuel temperature as an essential part of air-to-fuel ratio control. The sensor provides a DC voltage signal corresponding to the fuel temperature.
Sensor Supply
The sensor is powered from the 10 VDC Supply from the ECM.
Output Signal
The sensor outputs a DC voltage signal to the ECM. The DC voltage level varies with measured temperature. The valid voltage range is from 0.6 VDC to 5.1 VDC.
Control Diagnostics
521-00 (Not Flashing) Fuel Temperature Alarm Level indicates the fuel temperature exceeded 80°C (176°F). The ECM will display a constant diagnostic code.
521-12 (Not Flashing) Fuel Temperature Sensor Failure indicates the Fuel Temperature Sensor has provided data outside the range expected from a properly functioning sensor.
Figure 1: Fuel Temperature Sensor Diagram
Figure 2: Fuel Temperature Sensor Schematic
Refer to the Electrical Schematic for the terminations.
Figure 3: Fuel Temperature Sensor Output Table
Diagnostic Codes
Functional Test
Exhaust Temperature Input
System Operation
The ECM monitors the exhaust stack temperature to protect the engine. In most applications, high exhaust temperature will result in a shutdown, however in some limited applications, high exhaust temperature may be an alarm only. To determine if high exhaust temperature is an alarm or a shutdown, check the Personality Module settings for this engine. The Pyrometer Module(s) provide a contact closure when the exhaust temperature rises above the maximum acceptable level (adjustable on the Pyrometer). The switch provides a 0 VDC (-Batt) signal to the ECM by connecting Switch Input 5 (ECM connector J3 pin-37) to analog ground. When the switch is open, the voltage will be about 14 VDC.
The ECM can be selected (via the Personality Module) to either generate a Shutdown, generate a Alarm or not monitor the exhaust temperature at all.
Control Diagnostics
535-00 (Not Flashing) Exhaust Temperature Alarm Level indicates the exhaust temperature has risen above the maximum allowed level. The ECM will display a constant diagnostic code.
535-00 (Flashing) Exhaust Temperature Shutdown Level indicates the exhaust temperature has risen above the maximum allowed level. The ECM will display a flashing diagnostic code and the engine will shut down.
NOTE: The standard setting is 600°C (1110°F) as a shutdown.
Figure 1: Exhaust Temperature Input Diagram
Figure 2: Exhaust Temperature Input Schematic
Diagnostic Codes
Functional Test
Crank Angle Sensor
System Operation
The Crank Angle Sensor (CAS) is a passive magnetic pickup sensor used to indicate crankshaft angle to the Timing Control Module. The Crank Angle Sensor signal indicates cylinder No. 1 Top Center (TC) on compression and exhaust strokes. The signal is used to control timing and calculate actual timing and calculate engine rpm.
Output Signal
The sensor outputs a single sinusoidal pulse as the Top Center hole in the flywheel passes beneath the pickup. One pulse is generated for every crankshaft revolution. The time between pulses is proportional to the engine speed.
Figure 1: Crank Angle Sensor Diagram
Figure 2: Crank Angle Sensor Schematic
Figure 3: Crank Angle Sensor Output Table
Diagnostic Codes
Functional Test
Jacket Water Temperature Sensor
System Operation
The Jacket Water Temperature Sensor provides water temperature data to the Engine Control Module (ECM). The ECM monitors Jacket Water Temperature to protect the engine from overheating and to alert the operator of possible problems. The jacket water temperature is displayed on the CMS Module (gauge 2).
Sensor Supply
The sensor is powered from the 10 VDC supply from the ECM. This is shared with several other sensors.
Output Signal
The sensor outputs a DC voltage signal to the ECM. The DC voltage level varies with measured temperature. The varied voltage range is from about 0.6 VDC at -40°C (-40°F) to 5.1 VDC at 120°C (248F).
Control Diagnostics
110-00 (Not Flashing) High Jacket Water Temperature Alarm Level indicates the coolant water temperature exceeds the programmed parameter. The ECM will display a constant diagnostic code.
110-00 (Flashing) High Jacket Water Temperature Shutdown Level indicates the coolant water temperature has exceeded the programmed parameter for more than 1 minute. The standard Shutdown Point is 98°C (208°F), CoGen and BioGas unit may be different.
110-01 (Not Flashing) Low Jacket Water Temperature Alarm Level indicates the coolant water temperature does not reach the minimum programmed parameter value. The ECM will display a constant diagnostic code.
NOTE: If the Jacket Water Temperature is below 25°C (77°F) the ECM will display 110-01 alarm immediately. If the Jacket Water Temperature is above 25°C (77°F), but below 75°C (167°F) for more than 30 minutes the ECM will then also display the 110-01 Low Water Temp Alarm.
110-12 (Flashing) Jacket Water Temperature Sensor Failure indicates the Jacket Water Temperature Sensor has provided data outside the range expected from a properly functioning sensor.
Figure 1: Jacket Water Temperature Diagram
Figure 2: Jacket Water Temperature Schematic
Figure 3: Jacket Water Temperature Table
Diagnostic Codes
Functional Test
Engine Is Overloaded
System Operation
This input is used to provide an alarm to alert the operator of an engine overload condition and the control can not maintain desired engine rpm.
Figure 1: Engine Is Overloaded Diagram
Diagnostic Codes
Functional Test
TCM Flywheel Sensor
System Operation
The Flywheel Sensor is a passive magnetic pickup sensor that provides the engine speed and engine crankshaft position information to the Timing Control Module (TCM). Also used by the SCM and DMC.
Output Signal
The sensor outputs a sinusoidal wave form created as the flywheel ring gear teeth pass beneath the pickup. The frequency of the signal is proportional to engine seed where 3825 Hz equals 900 rpm.
Frequency/4.25=rpm
Figure 1: Flywheel Sensor Diagram
Figure 2: Flywheel/Crank Angle Sensor Schematic
Figure 3: Flywheel Sensor Output Table
Diagnostic Codes
Funtional Test
Ignition Timing
System Operation
The Magneto Interface Box (MIB) or the Caterpillar Ignition System (CIS) signal is a reduced voltage signal of the magneto's odd bank capacitor charge. This signal is sent from the Magneto Ignition Box (MIB) to the Timing Control. The wave form consists of pulses that indicate the discharge of the odd bank capacitor to fire the odd cylinders. One pulse is shown for each odd cylinder. This signal is used by the Timing Control to calculate ignition timing and some ignition diagnostics.
Interface Signal
Magneto Interface Ignition Pulse Signal- The waveform consists of pulses that indicate the discharge of the odd number cylinder banks capacitor to fire the odd numbered cylinders. One pulse is shown for each odd numbered cylinder.
Control Diagnostics
326-09 (Flashing) No Mag Interface Signal
326-11 (Flashing) Timing Problem Shutdown
The diagnostic codes for this signal are activated by the TCM when no ignition pulses are received from the MIB. This diagnostic code is only detected on startup while the engine speed is between 120 and 300 rpm. If no pulse is detected for 500 ms after engine speed is greater than 120 rpm and below 300 rpm, the diagnostic is activated. Related diagnostics are from Crank Angle Sensor or Timing/Speed Sensor failures.
Figure 2: Timing Schematic
Diagnostic Codes
Functional Test
Inlet Manifold Air Temperature Sensor
System Operation
The Inlet Manifold Air Temperature Sensor provides inlet air temperature data to the Engine Control Module (ECM). The ECM uses air temperature in the calculations for airflow and air-to-fuel ratio control. The ECM also uses the sensor to protect the engine against excessively high air temperatures. The inlet manifold temperature can be read from the CMS (gauge 1) or with the DDT.
Sensor Supply
The sensor is powered from the 10 VDC Supply from the ECM. This voltage supply is shared with several other sensors.
Output Signal
The sensor outputs a DC voltage signal to the ECM. The DC voltage level varies with measured temperature. The valid voltage range is from about 0.6 VDC at -40°C (-40°F) to 5.1 VDC at 120°C (248°F).
Control Diagnostics
172-00 (Not Flashing) High Inlet Manifold Air Temperature Alarm
When the load on the engine is below 50 percent of the rated load, the High Air Temp (Load less than 50 percent) Alarm Level is used as the Alarm setting.
When the load on the engine is above 50 percent of the rated load, the High Air Temp (Load greater than 50 percent) Alarm Level is used as the Alarm setting.
172-00 ( Flashing) High Inlet Manifold Air Temperature Shutdown
When the load on the engine is below 50 percent of the rated output, the High Air Temp (Load less than 50 percent) Shutdown Level is used as the Shutdown setting.
When the load on the engine is above 50 percent of the rated load, the High Air Temp (Load greater than 50 percent) Shutdown Level is used as the Shutdown setting.
172-12 ( Flashing) Inlet Manifold Air Temperature Sensor Failure
The Inlet Manifold Air Temperature Sensor has provided data outside the normal operating range expected from a properly functioning sensor. The failure is detected at voltages below 0.6 VDC or above 5.1 VDC.
Figure 1: Inlet Manifold Air Temperature Sensor Diagram
Figure 2: Inlet Manifold Air Temperature Sensor Schematic
Figure 3: Inlet Manifold Air Temperature Sensor Table
Diagnostic Codes
Functional Test
Personality Module
System Operation
The Personality module contains the software for the ECM that provides all of the features related to the ECM. The Personality Module provides a mechanism for changing functions of the control system. (Factory Programmable Only).
Figure 1: Personality Module Diagram
Diagnostic Codes
Functional Test
Coolant Inlet Pressure High
System Operation
The ESS monitors the inlet pressure of the coolant in the engine jacket water system and provides a switch output to the ECM indicating if coolant pressure is above the programmed inlet pressure of the switch. Although the sensor (or data) is read by the CMS module, the switch data output is relayed via the CAT Data Link to the ECM and processed. The ECM performs the diagnostics associated with this switch. The Coolant Inlet Pressure Switch provides an open contact when the coolant inlet pressure is below the maximum acceptable inlet pressure trip point. If the coolant inlet pressure is above 147 kpa gauge (21 psig), the switch is closed.
Control Diagnostics
462-00 (Not Flashing) Coolant Inlet Pressure High Alarm Level indicates the coolant inlet pressure is above the maximum allowed. The ECM will display a constant diagnostic fault code.
462-00 (Flashing) Coolant Inlet Pressure High Shutdown Level indicates the coolant inlet pressure is above the maximum allowed. The ECM will display a flashing diagnostic fault code and the engine will shut down.
NOTE: This is not a standard offering and requires a special Personality Module that can be programmed as either an alarm or a shutdown.
Figure 1: Coolant Inlet Pressure Switch Diagram
Figure 2: Coolant Inlet Pressure Switch Schematic
Diagnostic Codes
Functional Test
Coolant Outlet Pressure Sensor
System Operation
The Coolant Outlet Pressure Sensor provides pressure data to the ECM. The ECM monitors coolant outlet pressure to protect the engine against low coolant pressure. This sensor is used along with the Jacket Water Coolant Temperature Sensor to determine when the coolant has turned to steam for co-generation applications. Although this sensor (or data) is read by the CMS module, the sensor data output is relayed via the CAT Data link to the ECM and processed. The ECM performs the diagnostics associated with this sensor.
Sensor Signals
The coolant outlet pressure sensor provides a linear pulse width modulated (PWM) voltage signal corresponding to the pressure of the coolant from the jacket water system outlet to the ECM. Minimum expected output from the sensor is about 24 percent PWM and maximum expected PWM is about 90 percent.
Sensor Supply
The sensor is powered by Battery Power (18 to 32 VDC). The sensor receives power from battery positive and negative sourced from the ESS panel through wire S131.
Output Signal
The sensor outputs a PWM voltage signal to the CMS. The Duty Cycle varies with measured pressure. The valved signal range is from about 24 percent to 90 percent. The frequency of the signal is 5000 Hz.
kPa = (PWM percent -3.38) x 4.848
Control Diagnostics
109-01 (Not Flashing) Low Coolant Outlet Pressure Alarm Level indicates the Coolant Outlet Pressure is below an acceptable level. The ECM will display a constant diagnostic code.
109-01 (Flashing) Low Coolant Outlet Pressure Shutdown Level indicates the Coolant Outlet Pressure is below an acceptable level. The ECM will display a Flashing diagnostic fault code and engine will shut down.
109-12 (Flashing) Coolant Outlet Pressure Sensor Failure Shutdown Level indicates the Coolant Outlet Pressure Sensor has provided data outside the range expected from a properly functioning sensor for a certain period of time. The ECM will display a Flashing diagnostic fault code and the engine will shut down.
Figure 1: Coolant Outlet Pressure Sensor Diagram
Figure 2: Coolant Outlet Pressure Sensor Schematic
Figure 3: Coolant Outlet Pressure Sensor Table
Diagnostic Codes
Functional Test
Manifold Air Pressure Sensor
System Operation
The Manifold Air Pressure Sensor provides an absolute inlet air manifold pressure to the Engine Control Module (ECM). The ECM uses the Air Pressure along with Fuel Pressure, Fuel Temperature and Engine rpm to calculate the amount of fuel and airflow through the engine. The ECM monitors the air pressure for the air to fuel ratio control.
The Manifold Air Pressure can be read from the DDT or from the CMS Module.
The sensor is powered from the 20 or 24 VDC supply from the ECM. The 20 VDC supply is shared with other sensors.
The sensor outputs a PWM signal to the ECM. The signal level varies with measured pressure. The valid signal range is from approximately 17.3 percent to 95 percent duty cycle.
Control Diagnostics
106-01 Insufficient Boost Pressure Alarm indicates the engine is unable to attain maximum power because of insufficient air supply to the inlet manifold and the engine is unable to achieve the desired air pressure for steady state operation within a reasonable period of time. Sufficient pressure may be available to continue engine operation however fuel consumption and emissions may be compromised.
106-01 Insufficient Boost Pressure Alarm indicates the engine is unable to achieve the minimum permissible air pressure for steady state operation within a reasonable period of time. Fuel flow will be reduced to achieve an acceptable air-to-fuel ratio to compensate; however the engine will shut down.
NOTE: The alarm code will often occur on a failed engine start for any reason. If the problem becomes more severe, the ECM will reduce fuel and indicate a boost (106-12) Manifold Air Pressure Sensor Fault.
106-12 Manifold Air Pressure Sensor Failure indicates the Manifold Air Pressure Sensor has provided data outside the range expected from a properly functioning sensor or the control system has detected a failure in the indicated manifold air pressure likely caused by a sensor failure.
Figure 1: Air/Fuel Pressure Sensor Diagram
Figure 2: Air/Fuel Pressure Sensor Schematic
Figure 3: Manifold Air Pressure Sensor Output Table
Diagnostic Codes
Functional Test
Pressure Module Failure
System Operation
The Pressure Module provides Pulse Width Modulated (PWM) voltage signals corresponding to manifold air pressure and fuel pressure respectively. The module receives power from the +20VDC Supply from the Engine Control Module (ECM).
The ECM monitors the inlet manifold air pressure and fuel manifold pressure for air-to-fuel ratio control and power limiting. This module is essential to proper function of the engine.
Control Diagnostic 518-12
Pressure Module Failure Shutdown indicates that both sensors have provided data outside the range expected from properly functioning components.
Figure 1: Pressure Module Failure Diagram
Figure 2: Air/Pressure Sensor Schematic
Diagnostic Codes
Functional Test
Crankcase Pressure Sensor
System Operation
The Crankcase Pressure Sensor provides the pressure data (positive or negative) in the crankcase to the Engine Control Module (ECM). The ECM monitors the crankcase pressure to protect the engine. In most applications excessive crankcase pressure will result in a shutdown: however, in some limited applications crankcase pressure may be an alarm only. The Crankcase Pressure can be read from the CMS Gauge Module.
Sensor Supply
The sensor is powered from the 10 VDC Supply from the ECM. This supply is shared with several other sensors.
Output Signal
The sensor outputs a DC voltage signal to the ECM. The DC voltage level varies with measured pressure. The valid voltage range is from about 0.3 to 9.7 VDC. The signal can be interpreted as pressure.
(kPa) = [Signal (VDC) 4.2] X 0.4
Control Diagnostics
519-00 (Not Flashing) Crankcase Pressure Alarm Level
If the crankcase pressure exceeded the programmed parameter for a certain period of time. The ECM will display a constant diagnostic code.
519-00 (Flashing) Crankcase Pressure Shutdown Level
If the crankcase pressure exceeded the programmed parameter for a certain period of time. The ECM will display a flashing diagnostic code and the engine will shut down.
519-12 (Flashing) Crankcase Pressure Sensor Failure
The Crankcase Pressure Sensor has provided data outside the range expected from a properly functioning sensor.
Figure 1: Crankcase Pressure Sensor Diagram
Figure 2: Crankcase Pressure Sensor Schematic
Figure 3: Crankcase Pressure Sensor Output Table
Diagnostic Codes
Functional Test
Starting Air Pressure Sensor
System Operation
The Starting Air Pressure Sensor provides a linear pulse width modulating (PWM) voltage signal (5 kHz) corresponding to the pressure available to the starting motor control valve. The Starting Air Pressure can be read from the CMS Gage module (Gage 12). The sensor receives power from the system battery. Although this sensor (or data) is read by the CMS Module, the sensor data output is relayed via the CAT Data Link to the ECM and processed. The ECM performs the diagnostics associated with this sensor.
Output Signal
The output is a PWM signal that varies from 7 percent to 90 percent duty cycle.
kPa = (PWM percent -7) x 35
Figure 1: Starting Air Pressure Sensor Diagram
Figure 2: Starting Air Pressure Sensor Schematic
Figure 3: Starting Air Pressure Sensor Output Table
Diagnostic Codes
Functional Test
Fuel Pressure Sensor
System Operation
The Fuel Pressure Sensor provides the pressure difference between the fuel manifold and the air manifold to the Engine Control Module (ECM). The ECM uses the fuel pressure along with air pressure, fuel temperature and engine speed to calculate the amount of fuel flow through the engine. The fuel pressure can be read from the DDT.
The Fuel Pressure Sensor measures the differential pressure between the fuel manifold and the air manifold. Expected output is a positive pressure anytime the engine is running (necessary for there to be fuel flow into the engine). The fuel pressure line is a hose or metal line running from the fuel manifold to the pressure transducer. The sensor is powered from the 20 VDC supply from the ECM. The supply is shared with several other sensors.
Output Signals
The sensor outputs a PWM signal to the ECM. The signal level varies with measured pressure. The valid signal range is from approximately 16.7 percent to 95 percent duty cycle.
kPa=(PWM percent - 16.7) x1.49
Control Diagnostics
094-00 Fuel Pressure Limit Active Alarm indicates the maximum available fuel is being applied to the engine and indicated load is less than 100 percent. Governing accuracy and engine load capability are affected.
094-01 Insufficient Fuel Pressure Alarm indicates the engine is unable to obtain maximum power because of insufficient fuel supply to the fuel control system.
094-11 Fuel System Failure Shutdown indicates the control system has detected a failure in indicated fuel pressure.
094-12 Fuel Pressure Sensor Failure Shutdown indicates the sensor has provided data outside the range expected from a properly functioning sensor or the control system has detected a failure in indicated Fuel Pressure likely caused by a sensor failure.
The sensor outputs a PWM signal to the ECM. The signal level varies with measured pressure. The valid signal range is from approximately 16.7 percent to 95 percent duty cycle.
No Signal
The Fuel Pressure sensor provides no PWM signal, and the ECM has not detected either a pressure module failure, or a 20 VDC supply failure, or a shutdown in process.
Intermittent Signal (frequency noise)
The pressure signal is intermittent more than three times in 30 seconds, and the ECM has not detected either a pressure module failure or a shutdown in process.
Figure 1: Air/Fuel Pressure Sensor Diagram
Figure 2: Air/Fuel Pressure Sensor Schematic
Refer to the Electrical Schematic for the terminations.
Figure 3: Fuel Pressure Sensor Output Table
Diagnostic Codes
Functional Test
Oil Pressure Sensors
System Operation
The ECM measures both the filtered and unfiltered oil pressure. The ECM calculates the differential pressure by subtracting the filtered pressure from the unfiltered pressure. The ECM monitors engine oil deferential pressure to provide a means of monitoring the status of the oil filters. The differential oil pressure is displayed on the CMS Gage Module (gage 7).
NOTE: When the engine is shut down a sufficient conditions exist to ensure that no oil pressure is present, the ECM calibrates the two sensors to correct any error associated with inaccuracies of either sensor.
Sensor Supply
The sensors are powered by the battery (18 to 32 VDC) and receives power from battery positive and negative sourced from the ESS Panel and provides its signal back to the ESS Panel.
Output Signal
The sensor outputs a PWM voltage signal to the CMS. The Duty Cycle varies with measured pressure. The valid signal range is from about 10 to 90 percent. The frequency of the signal is 5000 Hz.
kPa=(PWM(%) - 9) X 9.31
Control Diagnostics
541-00 (Not Flashing) High Differential Oil Pressure Alarm Level indicates the Differential Oil Pressure data is above the range expected and the ECM will display a constant diagnostic code.
541-00 (Flashing) High Differential Oil Pressure Shutdown Level indicates the Differential Oil Pressure data is above the range expected for a certain period of time. The ECM will display a flashing diagnostic code and the engine will shut down.
541-12 (Not Flashing) Unfiltered Oil Pressure Alarm Levels indicates the Unfiltered Oil Pressure data is above or below the range expected and the ECM will display a constant diagnostic code.
541-12 (Flashing) Unfiltered Oil Pressure Shutdown Level indicates the Unfiltered Oil Pressure data is above or below the range expected for a certain period of time. The ECM will display a flashing diagnostic code and the engine will shut down.
543-12 (Not Flashing) Filtered Oil Pressure Alarm Level indicates the Filtered Oil Pressure data is above or below the range expected and the ECM will display a constant diagnostic code.
543-12 (Flashing) Filtered Oil Pressure Shutdown Level indicates the Filtered Oil Pressure data is above or below the range expected for a certain period of time. The ECM will display a flashing diagnostic code and the engine will shut down.
Figure 1: Oil Pressure Sensor Diagram
Figure 2: Oil Pressure Sensor Schematic
Figure 3: Oil Pressure Sensor Output Table
Diagnostic Codes
Functional Test
Oil Pressure Prelubrication Switch
System Operation
The ESS monitors the oil pressure and provides a switch output to the ECM indicating if oil pressure is below the programmed pressure of the switch.
Although this sensor (or data) is read by the CAT Data Link to the ECM and processed. The ECM performs the diagnostics associated with this sensor.
The Oil Pressure Prelubrication Switch provides an open contact when the pressure is below the minimum acceptable pressure trip point. If oil pressure is below 7 kpa (1 psi), the switch is closed.
Control Diagnostics
584-05 (Not Flashing) Prelubrication Oil Pressure Alarm Level
If the oil pressure during prelube is below the minimum allowed after the prelube oil pressure switch has been closed for 5 seconds, the ECM will display this diagnostic code.
584-05 (Flashing) Prelubrication Oil Pressure Switch Low Shutdown If the engine is running and the prelube pressure switch opens or fails the ECM will display this code.
Figure 1: Oil Pressure Prelubrication Switch Diagram
Figure 2: Oil Pressure Prelubrication Switch Schematic
Diagnostic Codes
Functional Test
Fuel (Quality) Energy Content Input
System Operation
The ECM monitors the Fuel Energy Content for air-to-fuel ratio control and power limiting. The engine control systems relies on sensor readings, combustion probes and buffers, and on the manual setting of the Fuel Energy Potentiometer to maintain consistent combustion and achieving the best performance and emissions.
The Fuel Energy Content signal may be provided either by the Fuel Energy Content Potentiometer and Fuel Energy Content Buffer located in the ESS panel, or it may be provided by one of several remote mounted modules.
Sensor Supply
The Fuel Energy Content input is a pulse width modulated (PWM) voltage signal corresponding to the user input or present fuel energy content. The sensor (potentiometer) is powered from the 20 VDC Supply from the ECM. This voltage supply is shared with several other sensors.
Output Signal
The buffer outputs a PWM signal to the ECM. The signal level varies with energy content (low heat value). Minimum expected input from the buffer is about 10 percent PWM and maximum expected PWM is about 90 percent. The failure is detected on complete loss of PWM signal. The valid signal range is from approximately 5 to 95 percent duty cycle.
Control Diagnostics
522-12 Fuel (Quality) Energy Content Input Failure Shutdown Indicates the potentiometer/buffer system has provided data outside the normal range expected from a properly functioning buffer or the control system has detected a failure in Indicated Fuel (Quality) Energy Content likely caused by a buffer failure.
Figure 1: Fuel (Quality) Energy Content Input Diagram
Figure 2: Fuel (Quality) Energy Content Input Schematic
Diagnostic Codes
Functional Test
Fuel (Quality) Energy Content
System Operation
The engine control system uses two methods for controlling the air-to-fuel ratio of the G3600 Engine. The first method (open loop) uses pressures, temperatures and the Fuel Energy Content Setting to calculate the air-to-fuel ratio of the engine. This method relies on sensor readings and on the manual setting of the Fuel Energy Potentiometer. The second method uses the combustion feedback system to monitor how the air and fuel actually burned in the combustion chamber. This method relies on the combustion probes and buffers. The actual air-to-fuel ratio that is used for control is the combination of the two. A basic air-to-fuel ratio is calculated using the first method and the second method creates a correction factor that compensates for any errors in the first, maintaining consistence combustion and achieving the best performance and emissions. The ECM monitors the combustion characteristics of the fuel using the combustion sensors and combustion buffers to maintain proper engine air-to-fuel ratio for emissions, fuel consumption and engine protection. The ECM requires that a minimum of one-half of the cylinders provide acceptable feedback in order to permit fuel quality correction. Without acceptable feedback, the control system is unable to compensate for changes in fuel quality, and result in an engine shutdown for protection. The ECM also requires that the fuel correction factor remain within a particular range while the engine is running. The correction factor from the combustion feedback system is displayed on the CMS Gage Module (gage 3) and the DDT. The Fuel (Quality) Energy Content can be read from the DDT and the ECM.
Control Diagnostics
529-00 Low Fuel (Quality) Energy Content Setting Limit Alarm indicates that the combustion feedback system has adjusted the fuel correction factor to a level that is higher than normal or the Fuel Correction Factor exceeds the High Fuel Correction Factor Level. This indicates there is a problem associated with one of the two air-to-fuel measuring techniques. Engine load capabilities are affected.
529-01 High Fuel (Quality) Energy Content Setting Limit Alarm indicates that the combustion feedback system has adjusted the fuel correction factor to a level that is lower than normal or the Fuel Correction Factor is below the Low Fuel Correction Factor Level. This indicates there is a problem associated with one of the two air-to-fuel measuring techniques.
529-02 Fuel (Quality) Energy Compensation Failure indicates one of two conditions or events. Case 1: That more than one-half of the total number of cylinder have one of the following diagnostic codes 501-02 through 516-02 Cylinder Misfire Greater Than 20 percent 501-08 through 516-08 Cylinder Continuously Misfiring 501-13 through 516-13 Prechamber Out of Calibration. Case 2: All of the cylinders are not receiving a primary magneto firing pulse (501-09 through 516-09 Ignition failure).
529-13 Fuel (Quality) Energy Content Out of Range indicates that the combustion feedback system has adjusted the fuel correction factor to a level that indicates that actual fuel energy is outside the range that the engine can properly burn. This engine is designed to operate on fuels with combustion characteristics defined by a Fuel Supply Minimum Level and a Fuel Supply Maximum Level.
Figure 1: Fuel (Quality) Energy Content Input Diagram
Diagnostic Codes
Functional Test
ECM Speed Sensor
System Operation
The ECM Engine Speed Sensor (MPU) is a magnetic pickup sensor, which generates its output signal from the flywheel teeth. The speed sensor signal is used to accurately govern the engine speed. This magnetic pickup is a three wire, powered, type of sensor and does not work like a two wired magnetic pickup. The Engine Speed Sensor must be installed with a one-half to three-quarters turn air gap. A properly adjusted air gap will prevent nuisance diagnostics.
Sensor Supply
The sensor is powered from the + 10 VDC Supply from the ECM. This voltage supply is shared with the Jacket Water Temperature Sensor, Fuel Temperature Sensor, and Crankcase Pressure Sensor.
Output Signal
The sensor outputs an alternating type signal whose frequency varies directly to the speed of the engine. The signal level varies between 0 and 10 volts. Each pulse in the signal corresponds to the passing of a ring gear tooth. The ring gear on the G3600 has 255 teeth resulting in 255 pulses for every engine revolution. The signal can be interpreted as
engine speed (RPM)=frequency (Hz)/255 X 60.
The frequency of this signal can be measured using a voltmeter with an AC frequency mode or an oscilloscope.
Figure 1: ECM Speed Sensor Diagram
Figure 2: ECM Speed Sensor Schematic
Figure 3: ECM Speed Sensor Output Table
Diagnostic Codes
Functional Test
Figure 4: Speed Sensor Output Table
Desired Speed Input
System Operation
The ECM monitors the Desired Speed to determine the speed at which to govern the engine.
The Desired Speed signal may be provided either by the Desired Speed Potentiometer and Desired Speed Buffer located in the ESS panel, or it may be provided by one of several remote mounted modules (possibly by non Caterpillar components).
In Generation Set (EPG) applications, the control system does not require the Desired Input to be present except when the engine is generating power (determined from measured load and/or parallel indication).
It is normal for some external desired speed sources (particularly the loadshare module) to not provide a desired speed signal until the generator is producing voltage. Under these conditions the ECM uses a Default Desired Speed.
The desired speed input can be read from the ECM status screen for RPM.
The Desired speed input is a linear pulse width modulated (PWM) voltage signal corresponding to the user input of present Desired Speed. The sensor (potentiometer) is powered from 20 VDC Supply from the ECM. This voltage supply is shared with several other sensors (i.e. Pressure Module, Fuel Energy Content Input, etc.)
The buffer outputs a PWM signal to the ECM, The signal level varies with the Desired Speed. Minimum expected input from the buffer is about 10 percent PWM and maximum expected PWM is about 90 percent. The failure is detected on complete loss of PWM signal. The valid signal range is from approximately 5 to 95 percent duty cycle.
Control Diagnostics 524-12
Desired Speed Input Failure Alarm indicates that the engine does not have a valid desired speed and is running at the default rated speed. This condition may be normal under some circumstances (such as a load share interface and manually energized generator exciter). This condition is permitted provided that the load on the engine has not exceeded 50%. This alarm will occur on generator set application engines.
524-12 Desired Speed Input Failure Shutdownindicates that the potentiometer has provided data outside the range expected from a properly functioning buffer or the control system has detected a failure in indicated Desired Speed likely caused by a buffer failure.
Figure 2: Desired Speed Input Schematic
Diagnostic Codes
Functional Test
Idle/Rated Input Fail
System Operation
The ECM monitors this switch input to determine if the engine should be run at the programmed low idle speed or run at the speed selected by the Desired Speed Input. This feature is necessary both for use by external control sources to limit engine speed to low idle (for driven equipment reasons) and also by the Engine Protection System to assure that the engine is not run at high speed until sufficient oil pressure is present. While this failure will not shut down an operating engine, it will prevent restart of the engine.
The Idle/Rated input to the ECM is connected to the 2301 relay contact of the SCM.
The relay contact is provided about 14 VDC through approximately 2 k Ohms resistance from the ECM. Once the SCM has determined conditions permit the engine to run at rated speed, it closes the contact to Ground.
This diagnostic code is based on the assumption that it should not be possible to have an oil pressure of sufficient magnitude to permit rated engine speed operation after engine is stopped and the postlube cycle has been completed. If this condition occurs it must indicate that the control system is receiving a false request to allow rated engine speed.
Figure 1: Idle/Rated Input Diagram
Figure 2: Idle/Rated Input Schematic
Diagnostic Codes
Functional Test
Shutdown Input Failure
System Operation
The ECM monitors this switch input to determine if the engine should be permitted to run. This signal is generated by the SCM (Run Relay). This feature is necessary both for use by external control sources to limit engine starting and also by the Engine Protection System to assure that the engine is not permitted to run. This failure can only be detected during a routine shutdown.. While this failure will not shut down an operating engine, it will prevent a restart of the engine. The Shutdown input to the ECM is connected to the Run Relay contact of the SCM. This input is configured to cause the engine to not start whenever this input is connected to ground. The relay contact is provided 14 VDC through approximately 2k Ohms resistance from the ECM. Once the SCM has determined conditions permit the engine to run, it opens the contact to Ground.
The "Run Relay" (RR) contact on the SCM is designed to open at the beginning of an engine shutdown. The contact should close on ALL shutdowns.
Figure 2: Shutdown Input Schematic
Diagnostic Codes
Functional Test
On Grid (Utility Parallel) Input Failure
System Operation
This input is used to provide modified governing characteristics, appropriate only for paralleled operation, when the engine is operating as a Generator Set paralleled with a utility. While this input only provides function in generator set applications, the ECM monitors this switch input in all applications.
The Parallel input is provided about 14 VDC through approximately 2k Ohms resistance from the ECM through wire M130. If the input is open (14 VDC), the govern use off-line gains. If the input is shorted to ground, the govern uses parallel gains.
Figure 2: On Grid (Utility Parallel) Input Failure Schematic
Diagnostic Codes
Functional Test
Oil Level Low
System Operation
The Oil Level Switch monitors the level of the oil in the engine crankcase and provides a switch level output to the ECM indicating if oil is below the level of the switch. The ECM uses this information to protect the engine from operation with insufficient oil.
The ECM can be selected to either generate a Shutdown, generate an Alarm, or not to monitor oil level at all.
The Oil Level Switch provides a closed contact (to 0 VDC) when the oil level drops below the minimum acceptable level. If the oil level is above the minimum acceptable level, the switch is open and the line will be at approximately 10 VDC.
Control Diagnostics
536-01 (Not Flashing) Oil Level Low Alarm Level If the Oil Level falls below the minimum allowed switch level, the ECM will display a constant diagnostic code.
536-01 (Flashing) Oil Level Low Shutdown Level If the Oil Level falls below the minimum allowed switch level, the ECM will display a flashing diagnostic code and the engine will shut down.
Figure 1: Oil Level Switch Diagram
Figure 2: Oil Level Switch Schematic
Diagnostic Codes
Functional Test
Coolant Level
System Operation
The Coolant Level Switch monitors the level of the coolant in the engine jacket water system and provides a switch level output to the ECM indicating if coolant below the level of the switch. The ECM uses this information to protect the engine from operation with insufficient coolant.
The ECM can be selected to either generate a Shutdown, generate an Alarm, or not to monitor coolant level at all. The Coolant Level Switch provides a closed contact (to 0 VDC) when the coolant level drops below the minimum acceptable level. If the coolant level is above the minimum acceptable level, the switch is open and the line will be at approximately 10 VDC.
Control Diagnostics
537-01 (Not Flashing) Coolant Level Low Alarm Level If the Coolant Level falls below the minimum allowed switch level, the ECM will display a constant diagnostic code.
537-01 (Flashing) Coolant Level Low Shutdown Level If the Coolant Level falls below the minimum allowed switch level, the ECM will display a flashing diagnostic code and the engine will shut down.
Figure 1: Coolant Level Low Diagram
Figure 2: Coolant Level Low Schematic
Diagnostic Codes
Functional Test
Air Restrictor
System Operation
The Inlet Air Restriction Sensor provides data to the ECM. The ECM monitors inlet air restrictions to provide a means of monitoring the status of the air filters. The air restriction can be read from the CMS module, (gauge 11) for the Right Air Restriction Sensor and (gauge 8) for the Left Air Restriction Sensor. In most applications, excessive air restriction will result in a shutdown, however in some limited applications excessive air restriction is an alarm only.
Although this sensor (data) is read by the CMS Module the sensor data output is relayed via the CAT Data Link to the ECM and processed. The ECM performs the diagnostics associated with this sensor.
Sensor Signals
The Air Restriction Sensor provides a linear pulse width modulated (PWM) voltage signal corresponding to the pressure drop at the turbocharger inlet to the ECM. Minimum expected output from the sensor is about 10 percent PWM and maximum expected PWM is about 70 percent.
Sensor Supply
The sensor is powered by battery power (18 to 32 VDC). The sensor receives power from battery positive and negative sources from the ESS panel and provides its signal back to the ESS panel though wire S412.
Output Signal
The sensor output a PWM signal to the CMS. The Duty Cycle varies with measured pressure. The valid signal range is from about 10 to 70 percent. The frequency of the signal is 5000 Hz.
Control Diagnostics
538-00 (Not Flashing) High Right Air Restriction Alarm Level indicates the air restriction exceeds the programmed parameter. The ECM will display a constant diagnostic code.
538-00 (Flashing) High Right Air Restriction Shutdown indicates the air restriction exceeds the programmed parameter for a certain period of time. The ECM will display a flashing diagnostic and the engine will shutdown.
538-12 (Not Flashing) Right Air Restriction Sensor Failure Alarm Level indicates the Air Restriction Sensor has provided data outside the range expected from a properly functioning sensor. The ECM will display a diagnostic code.
538-12 (Flashing) Right Air Restriction Sensor Failure Shutdown Level indicates the Air Restriction Sensor has provided data outside the range expected from a properly functioning sensor for a certain period of time. The ECM will display a flashing diagnostic code and the engine will shutdown.
539-00 (Not Flashing) Left Right Air Restriction Alarm Level indicates the air restriction exceeds the programmed parameter. The ECM will display a constant diagnostic code.
539-00 (Flashing) High Left Air Restriction Shutdown indicates the air restriction exceeds the programmed parameter for a certain period of time. The ECM will display a flashing diagnostic and the engine will shutdown.
539-12 (Not Flashing) Left Air Restriction Sensor Failure Alarm Level indicates the Air Restriction Sensor has provided data outside the range expected from a properly functioning sensor. The ECM will display a diagnostic code.
539-12 (Flashing) Left Air Restriction Sensor Failure Shutdown Level indicates the Air Restriction Sensor has provided data outside the range expected from a properly functioning sensor for a certain period of time. The ECM will display a flashing diagnostic code and the engine will shut down.
Figure 1: Air Restriction Sensor Diagram
Figure 2: Air Restriction Sensor Schematic
Refer to the Electrical Schematic for the terminators.
Figure 3: Air Restriction Sensor Output Table
Diagnostic Codes
Functional Test
Driven Equipment Input
System Operation
The Engine Control System monitors the Driven Equipment ready input to protect driven equipment. The ECM monitors this switch input to determine if the driven equipment should be permitted to operate. This feature is necessary both for use by external control sources. This failure can only be detected during an engine start sequence or while the engine is running to indicate the driven equipment is not ready for operation. Although this sensor (or data) is read by the CMS Module, the sensor data output is relayed via the CAT Data Link to the ECM and processed. The ECM performs the diagnostics associated with this sensor.
Control Diagnostics
540-07 (Not Flashing) Driven Equipment Input Failure Alarm Level indicates the Driven Equipment Switch Input is not ready. The ECM will display a constant diagnostic code.
540-07 (Flashing) Driven Equipment Input Failure Shutdown Level indicates the Driven Equipment Switch Input is not ready. The ECM will display a flashing diagnostic code and the engine will shut down.
Figure 1: Driven Equipment Input Diagram
Figure 2: Driven Equipment Input Schematic
Diagnostic Codes
Functional Test
DMC Flywheel Teeth Sensor
System Operation
The DMC Flywheel Teeth Sensor provides the engine rpm and engine crankshaft position information to the DMC Control Module. The sensor is shared with the Timing Control Module Speed Sensor.
The sensor outputs a sinusoidal signal as the flywheel teeth pass beneath the magnetic pickup sensor.
Sensor Signal
Output Signal the sensor generates a sinusoidal single generated as the flywheel gear teeth pass beneath the sensor. One sine wave is generated for every tooth and the signal frequency is proportional to the engine speed.
Control Diagnostic
The DMC Control Module will diagnose faults on the Flywheel Teeth Sensor if no signal is present or if too many or too few flywheel teeth are detected.
Figure 1: DMC Flywheel Teeth Sensor Diagram
Figure 2: DMC Flywheel Teeth Sensor Schematic
Refer to the Electrical Schematic for the terminators.
Diagnostic Codes
Functional Test
Detonation Sensor
System Operation
The Detonation Sensors provide an electrical signal of the mechanical engine vibrations to the Timing Control Module. The Timing Control monitors each detonation sensor signal to determine the severity of the combustion detonation.
Sensor Signals
Sensor Supply- The sensors are powered by the +13 VDC Sensor Supply from the Timing Control Module/DMC. The ground is provided by the Timing Control Module/DMC.
Output Signal- The sensor outputs a filtered and amplified electrical signal of the engine mechanical vibrations. The electrical frequency is the same as the mechanical frequency and the electrical signal amplitude is proportional to the vibration intensity. The signal is transmitted on a 6 VDC signal.
Control Diagnostics
* 318-12 (Flashing) No Detonation Sensor (Right)
* 318-12 (Flashing) No Detonation Sensor (Left)
The Timing Control Module will diagnose faults on each Detonation Sensor for a failed sensor module, cut orange transducer wire, wiring open or wiring short, -Battery, or +Battery open. The diagnostics are verified in two ways.
The ECM/TCM verifies the sensor signal DC offset voltage. If the DC offset is less than 2.5 VDC or greater than 9.6 VDC, the sensor fault is activated.
The ECM/TCM checks the detonation ratio from the sensor. If the engine is running and the detonation ratio is very low, the sensor fault is activated. The diagnostic time is one second for engine speed above 800 rpm and ten seconds for engine speeds between 500 and 800 rpm.
NOTE: Detonation protection is disabled for engine speeds less than 500 rpm. Related diagnostics are
325-00 (Not Flashing) Detonation Retarded Timing
325-00 (Flashing) Excessive Detonation Shutdown
Figure 1: Detonation Sensor Diagram
Figure 2: Detonation Sensor Power Supply Schematic (6 & 8 Cylinder Engines)
Figure 2: Detonation Sensor Power Supply Schematic (12 & 16 Cylinder Engines)
Diagnostic Codes
Functional Test
Figure 3: Accelerometer Diagram
Detonation Sensor Power Supply
System Operation
The DMC Control has two detonation signal outputs containing the detonation signal information for each engine bank. This information is transmitted to the Timing Control Detonation Sensor inputs for detonation analysis. The DMC Control Sensor Supply Outputs provide regulated voltage for the detonation sensors.
The DMC Control Module requires a battery power source for operation. From the supply voltage, the DMC Control Module provides the regulated voltages needed to run the control and power the sensors.
Control Output Signals
+13 Volt Sensor Supply The sensor supply voltage provided by the DMC Control Module is 13±1 VDC. The supply is capable of 250 mA maximum current. The output is protected against shorts to +Battery or -Battery. A single supply circuit provides the signal to all eight output connections.
Sensor Supply Ground
The sensor supply ground is provided by the DMC Control Module. It provides a common ground reference between the sensors and the DMC Control.
Output Signal
The output signal is a sinusoid waveform on a 6 VDC offset. The frequency and amplitude of the sinusoid waveform are from the input detonation sensor signals and represent the vibration and detonation activity on the engine.
Powerup Requirements
The power source must be capable of providing an instantaneous supply of 2 Amp at minimum 18 VDC. Insufficient supply power at powerup may not operate the DMC Control.
Steady State Requirements
The power source must be capable of supplying 1 Amp at a minimum of 18 VDC following the initial control powerup.
NOTE: See previous schematics on pages 4-199 and 4-200.
Figure 1: Detonation Sensor Power Supply Diagram
Functional Test
Cylinder Detonation Sensor
System Operation
The Detonation Mixing Control monitors the DC voltage level of all Detonation Sensors. If one sensor has a voltage that is more than 0.5 VDC different than the other sensors and the engine is shut down, the DMC will send a code to the engine ECM.
Detonation Sensor Input Signals
The detonation sensor input signals normally have a voltage of 6 to 7 VDC with 0.1 VAC. The AC portion is the detonation signal.
Detonation Sensor Output Signals
The detonation sensor output signals from the DMC contain one detonation sensor input signal at all times. The sensor-input signal corresponding to the firing signal is always transmitted on the output. The voltage on these outputs is normally 6 to 7 VDC with 0.1 to 1.0 VAC. The DMC will diagnose faults if one detonation sensor input has a voltage that is more than 0.5 VDC different than the other sensors, and the engine is shut down. If one sensor has a different DC voltage, the Timing Control Module can interpret the signal as false detonation.
Control Diagnostic
The DMC Control Module will diagnose faults if one detonation sensor input has a voltage that is more than 0.5 VDC different than the other sensors, and the engine is shut down. (if one sensor has a different DC voltage, the Timing Control Module can interpret the signal as false detonation). See Section 5 for details.
Figure 1: Cylinder Detonation Sensor Diagram
Refer to Detonation Sensor Power Supply Schematics Figures 2 and 3 on pages (4-199 and 4-200).
Diagnostic Codes
Functional Test
Detonation Shutdown/Retarded Timing
System Operation
The G3600 engine should be operating with an air/fuel margin of two between actual operation and detonation.
NOTE: Detonation protection is disabled for engine speeds less than 500 rpm. Related diagnostics are 325-00 (Not Flashing) Detonation retarded Timing 325-00 (Flashing) Excessive Detonation Shutdown.
NOTE: See previous schematics on pages 4-199 and 4-200.
Figure 1: Detonation Sensor Diagram
Diagnostic Codes
Functional Test
Cylinder Ignition
System Operation
The last two digits of the CID indicate which cylinder has failed (i.e. 504-09 would indicate that Cylinder No. 4 has failed).
The control system monitors each cylinder for primary ignition signals and combustion feedback to air-to-fuel ratio correction and for engine protection. To protect the engine, this condition will result in engine shutdown. The combustion feedback system uses Combustion Buffers, combustion probes, and a link into the ignition system to monitor the flame propagation speed during combustion.
Combustion Buffers
The Combustion Buffer is wired in series with the ignition primary. The primary pulse is generated by the Magneto or CIS, connected to the Combustion Buffer and then to the Ignition Transformer. This allows the buffer to monitor when the spark plug is fired.
The Combustion Buffer also monitors a Combustion Probe. When the flame of combustion reaches the probe, a signal is generated. The buffer uses the combustion signal to monitor when the flame has reached the edge of the cylinder. The Combustion Buffer times the flame propagation by sending a pulse that starts when the spark plug is fired and ends when the combustion signal is received.
The output of the Combustion Buffers are connected together in series. Each buffer provides its pulse on the common signal line. On a Vee engine all the buffers on the even bank are connected together. All the buffers on the odd bank except Cylinder No. 1 are connected together. Cylinder No. 1 is run on its own signal wire to the ESS panel. For in-line engines, the signals are the same as the Cylinder No. 1 and the odd bank of the Vee. All signals are provided to the ECM.
ECM Control Module
The ECM uses the Cylinder No. 1 pulse combined with engine speed to determine (based on crank angle and firing order) which pulse is associated with which cylinder. For example, on a 12 cylinder engine running at 900 rpm, after Cylinder No. 1 is received, the ECM expects the next pulse (Cylinder No. 12) to occur in 60 engine crankshaft degrees. At 900 rpm, the pulse should come in 11 milliseconds. The ECM considers any pulse that occurs between 5.5 mS and 16.5 mS after Cylinder No. 1 fires to be a Cylinder No. 12. The other cylinders are handled in the same manner.
Input and Output Signals: (Combustion Buffer)
The Combustion Buffer outputs a signal which is high (10 to 14 VDC) when there is no activity. When the cylinder fires, the buffer outputs a short pulse (0.05 mS to 0.2 mS) of 20 VDC followed by a low level (0 VDC). When the combustion signal from the combustion probe is received, the buffer again outputs a high level. The ECM measures the length of time the pulse is low to determine the flame propagation time for that cylinder.
NOTE: See previous schematics on pages 4-199 and 4-200.
Figure 1: Cylinder Ignition Diagram
Troubleshooting Ignition Faults
Troubleshooting Ignition faults will require an inspection of the magneto or CIS primary wiring to verify that the integrity of the wire insulation has not been compromised. This is particularly true when the fault code is occurring on an individual cylinder.
A visual inspection should be completed beginning from the amphenol connector at the back of the magneto or CIS box, through the wiring harness, into each cylinder and back to the ground lug on the engine. To accomplish this will require that the connectors at the Magneto/CIS and each of the cylinders be disassembled, the flexible conduit connections should be taken apart, and the junction box covers should be removed.
NOTE: Do NOT damage the wire while performing this check. Damaging the wire will create ignition problems.
The inspection should key on weak points in the wire insulation such as chafe marks that expose the bare wire and burnt spots that are caused by arcing through the insulation. Spiral wrap must be around the wire at each junction in the conduit. These areas represent possible short circuits in the wiring harness, and they must be repaired.
The lug that terminates the ground connections for the cylinders should also be inspected for loose wiring. Any loose wiring at this point should be corrected or resoldering the connection with a good heat source such as a propane torch. Replacement of the lug may be necessary if it is damaged beyond repair. A loose wire at this point will cause an open circuit on the primary side of the coil.
An open coil, extender, or spark plug may also generate a 501-09 through 516-09 Cylinder Ignition Failure Alarm (Not Flashing) Diagnostic code. Exchanging the parts in the bad cylinder with parts in a known cylinder is the quickest method for troubleshooting this type of failure.
Intermittent ignition faults, 501-09 through 516-09
Cylinder Ignition Failure Alarm (Not Flashing) Diagnostic codes could be somewhat difficult to troubleshoot, since they occur at random. If visual inspections and exchanging of the coil, extender, and spark plug did not isolate the problem then the following steps should be followed.
With the engine running at no load, carefully move the wire around in the conduit and connectors. To accomplish this will require that the flexible conduit connections should be taken apart, and the junction box covers should be removed. Do not disassemble the connectors at the magneto/CIS or individual cylinder because the wire would be exposed at these locations.
NOTE: Do NOT damage the wire while performing this procedure. Damaging the wire will create ignition problems.
NOTE: Use of gloves insulated for 600 volts is required to prevent electrical shock.
Observe engine operation while moving the wire, and note the location where a fault code can be generated. Inspect this area and repair as needed. It may be necessary to install a new harness if a repair can not be made.
Figure 2: Cylinder Ignition System
Figure 3: Combustion Signals
Figure 4: Combustion Buffer Output
Diagnostic Codes
Functional Test
Figure 5: Combustion Buffer Wiring
Figure 6: Combustion Buffer
Engine Type Programming
System Operation
The DMC is programmed with the engine type by the Gas Engine Control. The DMC Control Module will diagnostic the event of an engine type change to prevent accidental changes from occurring.
Control Diagnostic
The DMC Control Module will diagnose the event of an engine type change to prevent accidental changes occurring. This fault code may occur when the DMC is put on a new engine. If this occurs, turn the Mode Control Switch to the OFF/RESET position, and attempt to restart.
Diagnostic Codes
Functional Test
Cylinder #1 Ignition Signal
System Operation
The Cylinder #1 Combustion Buffer provides the cylinder #1 ignition signal with crankshaft rotation information to the DMC Control Module. The buffer outputs a pulse signal when the magneto/CIS energizes the ignition coil.
Output Signal
The ignition signal voltage is normally 12 VDC. When the magneto energizes the cylinder #1 ignition coil, the buffer signal pulses to 24 VDC and then drops to 0 VDC. The signal returns to 12 VDC when combustion is detected. One signal pulse is generated every two engine revolutions.
Control Diagnostic
The DMC Control Module will diagnose faults on the cylinder #1 ignition signal if no signal is present, or if a noisy signal is present.
Figure 2: Cylinder #1 Ignition Signal Schematic
Diagnostic Codes
Functional Test
Timing Control Communication (Data Link) Failure
System Operation
The Engine Control Module (ECM) and Timing Control Module (TCM) share information over a CAT Data Link (Timing Data Link). The information exchange between these two modules is essential for proper engine operation.
Figure 1: DATA Link Connections Diagram
Figure 2: DATA Link Connections Schematic
Diagnostic Codes
Functional Test
DMC Communication Failure
System Operation
The Engine Control Module (ECM) and other components share information over a CAT Data Link. The information exchange between these components is essential for proper engine operation.
Figure 1: Display DATA Link Failure Diagram
Figure 2: DMC Communication Failure
Diagnostic Codes
Functional Test
CAT DATA Link (Failure)
System Operation
The Engine Control Module (ECM) and other components share information over a CAT Data Link. The information exchange between these components is essential for proper engine operation and protection.
Figure 1: CAT Data Link (Display) Diagram
Figure 2: CAT Data Link (Display) Schematic
Diagnostic Codes
Functional Test
Magneto Out Of Calibration
System Operation
The Timing Control Module uses the magneto's maximum advanced timing to limits the timing range for programming desired timing. The Magneto Calibration (Mag Cal) mode places the maximum advanced timing of the magneto into the TCM memory. The maximum advanced timing of the variable timing magneto establishes limits on the timing window where the ignition timing may be electronically adjusted and guaranteed to fire the spark plugs.
During each engine start sequence, between 300 and 500 rpm, the TCM compares the stored maximum advanced timing to the current setting. The timing is calculated using the magneto interface (MIB) ignition pulses and the Crank Angle Sensor (CAS) signals.
Control Diagnostics 020-13
Magneto Out Of Calibration
This diagnostic will occur during engine start sequence only and indicates the TCM has detected a difference between the stored maximum advanced timing to the magneto setting. For example, if the last calibration of the magneto was 25 degrees BTC, but now the magneto is set with the maximum advanced timing of 35 degrees BTC.
Figure 1: Timing Diagram
Figure 2: Timing Schematic
Diagnostic Codes
Functional Test
GT Signal Fault
System Operation
When no pulses from the gear teeth are seen between the two pulses from the hall Effect Sensor, The screen displays "GT Signal Fault No Pulses".
Figure 1: GT Signal Fault Diagram
Diagnostic Codes
Functional Test
Figure 2: Caterpillar Ignition System Diagram
Bottom View
Figure 3: CIS Schematic
Hall Reset Fault (No Pulses)
System Operation
When too many pulses from the gear teeth are seen without a reset pulse from the Hall Effect Sensor, the CIS Display screen displays "Hall Reset Fault No Pulses".
Figure 1: Hall Reset Fault Diagram
Figure 2: Hall Effect Sensor Schematic
Figure 3: Hall Effect Sensor LED Diagram
Diagnostic Codes
Functional Test
Figure 4: CIS Connector View
Bottom View
TCM Reset Fault (Missing/No-Sync)
System Operation
When the reset signal from the TCM is missing or if the reset signal from the TCM has not been aligned properly with the signal from the Hall Effect sensor on the CIS Display screen displays "TCM Reset Fault (Missing / No-Sync)". This diagnostic fault is activated only while the TCM is in AUTO mode.
Figure 1: TCM Reset Fault (Missing / No-Sync)
Diagnostic Codes
Functional Test
Figure 2: CIS Connector View
Bottom View
Ignition System Failure
System Operation
Diagnostic Codes on consecutive cylinders in the firing order indicate a failure may exist in the Ignition System.
NOTE: For CIS setting information refer to System Operation Testing and Adjusting Manual for your engine.
Functional Test
CIS Failure
System Operation
The CIS has an internal problem.
Figure 1: Caterpillar Ignition System Diagram
Diagnostic Codes
Functional Test
Hydrax Pressure Switch
System Operation
The ESS monitors the Hyrax oil pressure system and provides a switch output to the ECM indicating if the pressure is above the programmed pressure of the switch to run the engine.
Although the sensor (or data) is read by the CMS Module, the sensor data output is relayed via the CAT Data Link to the ECM and processed. The ECM performs the diagnostics associated with this sensor. The Hydrax Pressure Switch provides a contact closure (to 0 VDC) when the Hydrax pressure is above 1240 kPa gauge (180 psi). The Hydrax Pressure Switch must be closed before the engine will start. The pressure should increase during normal engine cranking. The diagnostic code will appear if the pressure falls below the minimum acceptable pressure while the engine is running.
Control Diagnostic
465-05 (Flashing) Hydrax Pressure Is Low indicates that the Hydrax pressure is below the minimum allowed. The ECM will display a flashing diagnostic code and the engine will not start or will shut down if the engine is running.
Figure 1: Hydrax Pressure Switch Diagram
Figure 2: Hydrax Pressure Switch Schematic
Diagnostic Codes
Functional Codes
Hydrax Fuel Actuator
System Operation
This System Functional Test applies to engines with a Hydrax Actuator. If your system uses the Heinzmann Actuator refer to Heinzmann Fuel Actuator.
The ECM uses the Fuel Actuator to control the fuel flow to the engine for speed governing. The purpose of the Fuel Actuator is to maintain the desired engine rpm. The Fuel Actuator is a hydraulically powered Actuator with an electrically driven solenoid.
The ECM sends a position command signal to the Hydrax driver module. The command signal is a pulse width modulated (PWM) signal varying from 0 to 100 percent. The driver module converts the ECM position command signal to a current signal. The current signal is then sent to the Fuel Actuator solenoid to move the Actuator shaft to the desired position. A separate position feedback sensor monitors shaft rotation and sends a % PWM signal to the driver module. The driver module converts the PWM feedback signal to an analog voltage signal and sends it to the ECM.
The position feedback voltage signal sent to the ECM is proportional to the actual position of the Fuel Actuator Valve. At the fully closed position the feedback voltage should be less than the 1.7±0.1 VDC for proper Actuator calibration. As a reference, at the fully opened position the feedback voltage will be greater than 5 VDC.
The installation setup procedure of the mechanical linkage requires that the Fuel Actuator position be slightly less than full open at the fully closed position of the fuel control valve. This will insure that the fuel valve is fully closed when engine shutdown is desired.
The DDT Service Tool and a 9U-7330 Fluke Multimeter can be used for troubleshooting the Fuel Actuator System.
The ECM calibrates the Fuel Actuator during normal shutdowns. To initiate calibration, the engine speed must be above 550 rpm before shutting the engine down and no shutdown diagnostic codes present. When the Actuator is calibrated, the minimum and maximum feedback and commands allowed are calculated. The calibration sequence is as follows.
Step 1. Shutdown is initiated (Fuel Actuator closed).
Step 2. Once the fuel pressure reaches 1.0 kPa (0.15 psi) the Fuel Actuator is opened and calibrated. If at anytime the fuel pressure exceeds 30.0 kPa (4.35 psi) the calibration process is aborted and a 017-12 Gas Shutoff Valve Failure diagnostic code is generated.
Step 3. The calibration values are recorded in permanent memory and are used for diagnostic purposes.
Figure 1: Hydrax Actuator Diagram
Figure 2: Hydrax Actuator Schematic
Diagnostic Codes
Functional Test
Hydrax Choke Actuator
System Operation
This System Functional Test applies to engines with a Hydrax Actuator. If your system uses the Heinzmann Actuator refer to Heinzmann Choke Actuator.
The ECM uses the Choke Actuator to control the inlet air pressure to the engine for air-to-fuel ratio control. The purpose of the Choke Actuator is to maintain the desired air-to-fuel ratio to the engine during low load conditions. The Choke Actuator is a hydraulically powered Actuator with an electrically driven solenoid.
The ECM sends a position command signal to the Hydrax driver module. The command signal is a pulse width modulated (PWM) signal varying from 0 to 100 percent. When the load on the engine is above approximately 50% during normal engine operation, the Choke Actuator will be fully open a 0% PWM position command signal. The driver module converts the ECM position command signal to a current signal. The current signal is then sent to the Choke Actuator solenoid to move the Actuator shaft to the desired position. A separate position feedback sensor monitors shaft rotation and sends a % PWM signal to the driver module. The driver module converts the PWM feedback signal to an analog voltage signal and sends it to the ECM.
The position feedback voltage signal sent to the ECM is proportional to the actual position of the Choke Actuator. At the fully open position the feedback voltage should be 1.7±0.1 VDC. At the fully closed position the feedback voltage should be greater than 8 VDC for proper Actuator calibration.
The installation setup procedure of the mechanical linkage requires that the Choke Actuator position be fully closed slightly less than the fully closed position of the choke butterfly valve. This will insure that the choke valve does not stick in the air intake duct during hard shutdowns. There is also an adjustable stop screw on the butterfly shaft/air intake housing.
The DDT Service Tool and a 9U-7330 Fluke Multimeter can be used for troubleshooting the Choke Actuator System.
Actuator Calibration
The ECM calibrates the Choke Actuator during the normal start sequence of the engine. The engine speed must be greater than 50 rpm. When the Actuator is calibrated, the minimum and maximum feedback and commands allowed are calculated. The ECM sends a signal to move the Actuator from the closed to the open position. The calibration values are recorded by the ECM and used for diagnostic purposes.
NOTE: See schematic on page 4-285.
Figure 1: Hydrax Actuator Diagram
Diagnostic Codes
Functional Test
Hydrax Wastegate Actuator
System Operation
This System Functional Test applies to engines with a Hydrax Actuator. If your system uses the Heinzmann Actuator refer to Heinzmann Wastegate Actuator.
The ECM uses the Wastegate Actuator to control the inlet air pressure to the engine for air-to-fuel ratio control. The purpose of the Wastegate Actuator is to maintain the desired air-to-fuel ratio to the engine at load conditions above 50%. The Wastegate Actuator is a hydraulically powered Actuator with an electrically driven solenoid.
The ECM sends a position command signal to the Hydrax driver module. The command signal is a pulse width modulated (PWM) signal varying from 0 to 100 percent.
The driver module converts the ECM position command signal to a current signal. The current signal is then sent to the Wastegate Actuator solenoid to move the Actuator shaft to the desired position. A separate position feedback sensor monitors shaft rotation and sends a % PWM signal to the driver module. The driver module converts the PWM feedback signal to an analog voltage signal and sends it to the ECM.
The position feedback voltage signal sent to the ECM is proportional to the actual position of the Wastegate Actuator. At the fully closed position the feedback voltage should be 1.7±0.1 VDC. At the fully open position the feedback voltage should be greater than 8 VDC for proper Actuator calibration.
The installation setup procedure of the mechanical linkage requires that the Wastegate Actuator position be fully extended at slightly less than the full closed position of the Wastegate butterfly valve. This will insure that the butterfly valve does not stick in the housing in the closed position.
The DDT Service Tool and a 9U-7330 Fluke Multimeter can be used for troubleshooting the Wastegate Actuator System.
Actuator Calibration
The ECM calibrates the Wastegate Actuator during the normal start sequence of the engine. The engine speed must be greater than 50 rpm. When the Actuator is calibrated, the minimum and maximum feedback and commands allowed are calculated. The ECM sends a signal to move the Actuator from the closed to the open position. The calibration values are recorded by the ECM and used for diagnostic purposes.
NOTE: See schematic on page 4-285.
Figure 1: Hydrax Actuator Diagram
Diagnostic Codes
Functional Test
Heinzmann Fuel Actuator
System Operation
This System Functional Test applies to engines with a Heinzmann Actuator. If your system uses the Hydrax Actuator refer to Hydrax Fuel Actuator.
The ECM uses the Fuel Actuator to control the fuel flow to the engine for speed governing. The purpose of the Fuel Actuator is to maintain the desired engine rpm. The Fuel Actuator receives a command signal (% PWM) from the ECM based on the difference in the actual engine rpm and the desired engine rpm.
The Fuel Actuator is an electric Actuator powered from the battery system through a relay (SR2) and a fuse in the engine junction box.
The ECM sends a desired (command ) position signal to the Fuel Actuator. The signal is a pulse width modulated (PWM) signal varying from 0 to 100 percent. At approximately 10 percent signal, the Actuator begins to move from the fully closed position (0 %).
NOTE: Under normal engine operation, travel is limited to 50 percent where the Actuator reaches the fully open position (maximum fuel delivery is at 50 percent). The Actuator provides a position feedback to the EM. The feedback signal is an analog voltage proportional to the actual position of the Fuel Actuator. One VDC corresponds to fully closed position and 9 VDC corresponds to the fully open position with 5 VDC being the mid position.
The installation procedure requires the Actuator to be partially open (2%) when the fuel valve is fully closed. Under conditions where the Actuator is fully closed the expected feedback voltage form the Actuator should be less than 2 VDC.
The DDT Service Tool and a 9U-7330 Fluke Multimeter can be used for troubleshooting the Fuel Actuator System.
The ECM calibrates the Fuel Actuator during normal shutdowns. To initiate calibration, the engine speed must be above 550 rpm before shutting the engine down and no shutdown diagnostic codes present. When the Actuator is calibrated, the minimum and maximum feedback and commands allowed are calculated. The calibration sequence is as follows.
Step 1. Shutdown is initiated (Fuel Actuator closed).
Step 2. Once the fuel pressure reaches 1.0 kPa (0.15 psi) the Fuel Actuator is opened and calibrated. If at anytime the fuel pressure exceeds 30.0 kPa (4.35 psi) the calibration process is aborted and a 017-12 Gas Shutoff Valve Failure diagnostic code is generated.
Step 3. The calibration values are recorded in permanent memory and are used for diagnostic purposes.
Figure 1: Fuel Actuator Diagram
Figure 2: Fuel Actuator Schematic
Refer to Electrical Schematic for the terminations and wire color.
Diagnostic Codes
Functional Test
Figure 3: Heinzmann Average Performance Curve
Heinzmann Choke Actuator
System Operation
This System Functional Test applies to engines with a Heinzmann Actuator. If your system uses the Hydrax Actuator refer to Hydrax Choke Actuator.
The ECM uses the Choke Actuator to control the inlet air pressure to the engine from air-to-fuel ratio control. The purpose of the Choke Actuator is to maintain air-to-fuel ratio at partial (low load). The Choke Actuator receives a command signal (% PWM) from the ECM to limit the airflow into the engine during partial (low) load operation. When the load on the engine is above approximately 50 percent during normal engine operation, the Choke Actuator will be fully open to 0 percent.
Power Supply
The Choke Actuator is an electric Actuator powered from the battery system through a relay (SR2) and a fuse in the engine junction box.
Device Signals
The ECM sends a desired (command) position signal to the Actuator. The signal is a pulse width modulated signal varying form 0 to 100 percent. At approximately 10 percent signal, the Actuator begins to move from the fully open position. From that point, the Actuator moves proportionally to the signal until approximately 90 percent signal where the actuator reaches the fully closed position (50 percent PWM corresponds to mid-travel). The Actuator provides position feedback to the feedback signal is an analog voltage proportional to the actual position of the actuator. One volt (1 VDC) corresponds to fully open position and 0 VDC corresponds to fully closed position (5 VDC corresponds to midposition).
The DDT Service Tool and a 9U-7330 Fluke Multimeter can be used for troubleshooting the Choke Actuator System.
Actuator Calibration
The ECM calibrates the Choke Actuator during the normal start sequence to start the calibration. The engine speed must be above 50 rpm. When the Actuator is calibrated, the minimum and maximum feedback and commands allowed are calculated. The ECM sends a signal to move the Actuator from the closed to the open position. The calibration values are recorded and are used for diagnostic purposes.
Figure 1: Choke Actuator Diagram
Diagnostic Codes
Figure 2: Choke Actuator Schematic
Functional Test
Figure 3: Heinzmann Average Performance Curve
Heinzmann Wastegate Actuator
System Operation
This System Functional test applies to engines with a Heinzmann Actuator. If your system use the Hydrax Actuator refer to Hydrax Wastegate Actuator.
The ECM uses the Wastegate Actuator to control the inlet air pressure to the engine for air-to-fuel ratio control. The purpose of the Wastegate Actuator is to maintain air-to-fuel ratio. The Wastegate Actuator receives a command signal (% PWM) from the ECM to provide the desired air-to-fuel ratio by controlling the exhaust bypass (around the turbocharger turbine).
Power Supply
The Wastegate Actuator is an electric Actuator powered by from the battery system through a relay and a fuse in the engine junction box.
Device Signals
The ECM sends a desired (command) position signal to the Actuator. The signal is a pulse width modulated signal varying form 0 to 100 percent. At approximately 10 percent signal, the Actuator begins to move from the fully closed position. From that point, the Actuator moves proportionally to the signal until approximately 90 percent signal where the Actuator reaches the fully open position (50 percent PWM corresponds to mid-travel)
The Actuator provides position feedback to the EM The feedback signal is an analog voltage proportional to the actual position of the Actuator. One volt (1 VDC) corresponds to fully open position and 0 VDC corresponds to fully closed position (5 VDC corresponds to midposition).
The DDT Service Tool and a 9U-7330 Fluke Multimeter can be used for troubleshooting the Wastegate Actuator System.
Actuator Calibration
The ECM calibrates the Wastegate Actuator during the normal start sequence. To start the calibration, the engine speed must be above 50 rpm. When the Actuator is calibrated, the minimum and maximum feedback and commands allowed are calculated. The ECM sends a signal to move the Actuator from the closed to the open position. The calibration values are recorded and are used for diagnostic purposes.
Figure 1: Wastegate Actuator Diagram
Figure 2: Wastegate Actuator Schematic
Diagnostic Codes
Functional Test
Figure 3: Heinzmann Average Performance Curve
