HEAD 9J5645 - Caterpillar

Illustration 1 g00531020
System Schematic For Generator Fault Relay (GFR) On MUI Engines
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System Schematic For Generator Fault Relay (GFR) On PEEC Engines
Illustration 3 g00687333
System Schematic For Generator Fault Relay (GFR) On EUI Engines The GSC+ uses the generator fault relay (GFR) in order to activate the circuit breaker for the shunt trip coil during a shutdown fault. The GFR is located within the relay module. The optional circuit breaker is located in the generator housing.Note: Whenever the GSC+ activates or the GSC+ attempts to activate the GFR, "K2" is shown on the lower display. When the GFR is not activated, "K2" is not shown.The possible cause of a CID 0442 FMI 12 is an open coil or a shorted coil of the GFR.The system response to this diagnostic code is listed below.
When a CID 0442 FMI 12 occurs and the GFR is activated, the diagnostic code will not have an effect on the system. The system is not affected because the optional circuit breaker is already open and shutdown mode is functioning. The generator is already off-line.
If a CID 0442 FMI 12 occurs and the GFR is not activated, the GFR cannot activate the shunt trip coil of the optional circuit breaker when a shutdown fault occurs.The GSC+ treats a CID 0442 FMI 12 as an alarm fault. Active alarm faults are shown on the display when the "Alarm Codes" key is pressed. The ECS must be in any position except the OFF/RESET position. Clear the diagnostic code from the fault log after troubleshooting is complete.This troubleshooting procedure is for an active CID 0442 FMI 12 or the troubleshooting procedure is for an inactive CID 0442 FMI 12.Test Step 1. CHECK THE STATUS OF THE DIAGNOSTIC CODE.
Turn the ECS to the OFF/RESET position and then turn the ECS to the STOP position.
Press the "Alarm Codes" key.
Observe the upper display. Check that the CID 0442 FMI 12 is active.
If the diagnostic code is not active, enter the Service Mode. View the fault log for a OP1. Check that the diagnostic code is inactive.Expected Result:A CID 0442 FMI 12 is displayed as an active diagnostic code or CID 0442 FMI 12 is displayed as an inactive diagnostic code.Results:
OK - The CID 0442 FMI 12 is active or the CID 0442 FMI 12 is inactive. Proceed to test step 2.
NOT OK - The CID 0442 FMI 12 has not occurred. The diagnostic code is not active and the diagnostic code is not inactive.STOPTest Step 2. CHECK THE INTERNAL CABLE OF THE RELAY MODULE.Note: Only open the relay module in a dry environment. If the inspection and repair takes more than approximately twenty minutes replace the desiccant bag in the GSC+ housing. See Testing And Adjusting, "Relay Module - Replace".
Turn the ECS to the OFF/RESET position.
Disconnect the battery negative cable.
Temporarily, remove the relay module from the GSC+. See Testing And Adjusting, "Relay Module - Replace".
Check the cable that attaches the relay module to the GSC+.Expected Result:The cable should be firmly seated in the connector.