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

Illustration 1	g00527056
System Schematic For Engine Oil Pressure Sensor (EOPS)

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

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

• The 0 kPa (0 psi) is approximately 13% duty cycle. The voltage will be approximately 1.0 DCV.

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

Note: The GSC+ is usually programmed to treat an oil pressure sensor fault as an alarm fault. The factory default for P004 is 0. If the GSC+ is programmed to shutdown for an oil pressure sensor fault, then it is not necessary to press the alarm codes key in order to view the CID FMI. P004 is equal to 1 for a shutdown fault. The CID FMI is automatically shown on the upper display.

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

CID 100 FMI 2 - Pressure Sensor (Engine Oil)

CID 110 FMI 2 - Temperature Sensor (Engine Coolant)

CID 111 FMI 3 - Fluid Level Sensor (Engine Coolant)

CID 175 FMI 3 - Temperature Sensor (Engine Oil)

CID 190 FMI 3 - Speed Sensor (Engine)

CID 336 FMI 2 - Switch (Engine Control)

CID 590 FMI 9 - Engine (ECM)

The possible causes of a CID 100 FMI 2 fault are listed below:

• The base signal of the sensor is beyond accepted limits.

• The duty cycle of the sensor signal is beyond accepted limits.

Begin performing these procedures only when CID 100 FMI 2 is showing and the "DIAG" indicator is FLASHING on the upper display. The flashing indicator means that the fault is active. The GSC+ treats a CID 100 FMI 2 fault as an alarm fault. Active alarm faults are shown on the display when the "Alarm Codes" key is pressed and the engine control switch (ECS) is in any position except the OFF/RESET position. For an inactive fault, the problem may be intermittent. Use Illustration 1, and see Testing And Adjusting, "Electrical Connector - Inspect" in order to troubleshoot an inactive fault. Clear the fault from the fault log after troubleshooting is complete.

Note: The operator may choose to replace this procedure by troubleshooting the sensor signal with a meter that is capable of measuring frequency. The meter must also measure a duty cycle.

Note: If fault CID 269 is present, then correct the fault prior to starting the procedure.

1. Check the GSC+ and the harness.

   1. Make sure that CID 100 FMI 2 is showing on the display.

   2. Turn the ECS to the OFF/RESET.

   3. Disconnect the sensor from the engine harness. The sensor remains fastened to the engine.

   4. Turn the ECS to the STOP position.

   5. Press the "Alarm Codes" key. The "Alarm Codes" key does not need to be pressed for a shutdown fault.

   6. Monitor the display. Check whether the CID 100 FMI 2 is showing on the display. If CID 100 FMI 2 is not showing, then CID 100 FMI 2 is inactive. Now, the CID 100 FMI 3 should be showing. CID 100 FMI 3 is active.

      Expected Result: The voltage should be 8.0 ± 0.5 DCV.

      Results:

      • OK: The GSC+ and the harness function properly. Therefore, the sensor is faulty. Replace the sensor. See Testing And Adjusting, "Pulse Width Modulated (PWM) Sensor - Test" for more sensor testing. STOP.

      • NOT OK: The CID 100 FMI 2 fault is still showing. The harness or the GSC+ is faulty. Proceed to Step 2.

2. Check the GSC+.

   1. Turn the ECS to the OFF/RESET position.

   2. Disconnect the harness connector from the GSC+. Turn the GSC+ to the STOP position.

   3. Press the "Alarm Codes" key.

   4. Check if the CID 100 FMI 2 is not showing. This means that the CID 100 FMI 2 is inactive. CID 100 FMI 3 is now showing. CID 100 FMI 3 is now active.

      Expected Result: CID 100 FMI 2 is not showing. The CID 100 FMI 3 is now showing. The CID 100 FMI 3 is now active.

      Results:

      • OK: The GSC+ functions properly. Therefore, the signal wire is faulty in the harness. Troubleshoot the signal wire in the harness between the sensor connector and the GSC+ connector. See Testing And Adjusting, "Electrical Connector - Inspect" for procedures on checking the electrical connectors and terminals. STOP.

      • NOT OK: The CID 100 FMI 2 fault is still showing. The GSC+ is faulty. Replace the GSC+. For information on replacing the GSC+, see Testing And Adjusting, "EMCP Electronic Control (Generator Set) - Replace". STOP.