ELBOW 2V6746 - Caterpillar

Illustration 1 g00744563
Schematic For The Sensor Power SupplyThe EMCP II has a sensor supply voltage of 8 DCV from the GSC that powers the engine sensors. The sensors that are displayed in 1 illustration may vary. The sensors may vary according to the engine. See table 1 in order to determine the sensors that are on your engine.
Table 1
Sensor     MUI Engines     EUI Engines     PEEC Engines    
Coolant Temperature     Yes     No     Yes    
Oil Pressure     Yes     No     Yes    
Coolant Loss     Yes     Yes     Yes    The engine coolant fluid level sensor is optional.The sensor power supply functions whenever power is applied to the GSC.The GSC is usually programmed in the factory. The GSC deals with a problem with the sensor power supply CID 0269 FMI 03 as an alarm fault. P04 = 0. If the GSC is programmed to shutdown, P04 is equal to 1 for a problem with the sensor power supply. It is not necessary to press the "Alarm Codes" key in order to view the CID 0269 FMI 03. The CID 0269 FMI 03 is automatically shown on the upper display.Diagnostic codes are created when the harness connector is disconnected from the GSC during these troubleshooting procedures. Clear these created diagnostic codes after the particular problem is corrected and the particular diagnostic code is cleared. The possible cause of a CID 0269 FMI 03 happens when the voltage of the sensor power supply is greater than 8.5 DCV.Begin performing these procedures only when CID 0269 FMI 03 is showing and the "DIAG" indicator is FLASHING on the upper display. The GSC treats a CID 0269 FMI 03 as an alarm fault. Active alarm faults are shown on the upper 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 diagnostic code, the problem may be intermittent. To troubleshoot an inactive diagnostic code, use the preceding system schematic and see Testing And Adjusting, "Electrical Connector - Inspect". Clear the diagnostic code from the fault log after the troubleshooting procedure is completed.Test Step 1. CHECK THE GSC.
Disconnect the harness 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 for the CID 0269 FMI 03.Expected Result:The CID 0269 FMI 03 should not be showing. The diagnostic code should be inactive.Results:
OK - The CID 0269 FMI 03 is not showing. The GSC is functioning properly. Therefore, the engine harness has a short to "B+".Repair: Repair the engine harness or replace the engine harness. Stop.
NOT OK - The CID 0269 FMI 03 is not showing.Repair: The GSC may have failed. It is unlikely that the GSC has failed. Exit this procedure and perform this entire procedure again. If the problem remains, replace the GSC. See Testing And Adjusting, "EMCP Electronic Control (Generator Set) - Replace". Stop.