ENGINE AR 3816476 - Caterpillar

Illustration 1 g00596717
System Schematic For Sensor Power SupplyThe EMCP II has an 8 DCV sensor supply from the GSC that powers three engine sensors: the fluid level sensor (engine coolant), the temperature sensor (engine coolant) and the pressure sensor (engine oil). The sensor power supply functions whenever power is applied to the GSC. Note: The GSC is usually programmed to treat a fault with the sensor power supply (CID 269) as an alarm fault (P04 = 0). If the GSC is programmed to shut down (P04 = 1) for a fault with the sensor power supply, then the alarm codes key is not needed in order to view the CID FMI. The CID FMI is automatically shown on the upper display.Note: Diagnostic codes are created when the harness connector (40 contact) is disconnected from the GSC during these troubleshooting procedures. Clear these created diagnostic codes after the particular fault is corrected. In a properly operating system, when the harness connector is removed from the GSC, the following diagnostic codes are recorded.
CID 100 FMI 3 pressure sensor (engine oil)
CID 110 FMI 3 temperature sensor (engine coolant)
CID 111 FMI 3 fluid level sensor (engine coolant)
CID 190 FMI 3 speed sensor (engine)
CID 331 FMI 2 switch (engine control)
CID 336 FMI 2 switch (engine control)ProcedureThe following condition is a possible cause of a CID 269 FMI 3.
The voltage of the sensor power supply is less than 7.5 DCV.Begin performing these procedures only when CID 269 FMI 4 is showing and the "DIAG" indicator is FLASHING on the upper display. The GSC treats a CID 269 FMI 4 as an alarm fault. Active alarm faults are shown on the display when the alarm codes key is pressed. Also, the ECS is in any position except the OFF/RESET position. For an inactive fault, the problem may be intermittent. To troubleshoot an inactive fault, use the preceding system schematic. See Testing And Adjusting, "Electrical Connector - Inspect". Clear the diagnostic code from the fault log after troubleshooting is complete.
Check the GSC.
Disconnect the harness connector from the GSC.
Turn the ECS to OFF/RESET and then turn the ECS to the STOP position.
Press the alarm codes key.
Observe the upper display in order to verify that the CID 269 FMI 4 is showing.Expected Result: The CID 269 FMI 4 should NOT be showing. Results:
OK - The GSC is functioning properly. Therefore, the engine harness or a sensor is faulty. Proceed to 2.
NOT OK - The GSC is faulty, replace the GSC. See Testing And Adjusting, "EMCP Electronic Control (Generator Set) - Replace". STOP.
Check the fluid level sensor (engine coolant).
Turn the ECS to OFF/RESET.
Reconnect the harness connector to the GSC.
Disconnect the engine harness from the fluid level sensor (engine coolant).
Turn the ECS to STOP.
Press the alarm codes key.
Verify that CID 269 FMI 4 is showing.Expected Result: If the sensor is the cause of this diagnostic code, then CID 269 FMI 4 should NOT be showing when the sensor is disconnected. Results:
OK - The CID 269 FMI 4 is NOT showing. The