CYLINDER GP-BOOM 2597926 - Caterpillar

Illustration 1 g00531356
System Schematic For Starting Motor Relay (SMR) For MUI Engines
Illustration 2 g00680589
System Schematic For Starting Motor Relay (SMR) For EUI EnginesThe GSC+ uses the starting motor relay (SMR) to activate the starting motor magnetic switch (SMMS). The SMR is located within the relay module.Note: Whenever the GSC+ activates or the GSC+ attempts to activate the SMR, "K4" is shown on the lower display. When the SMR is not activated, "K4" is not shown.The possible cause of a CID 0444 FMI 12 is an open coil or a shorted coil of the SMR.The system responses to this diagnostic code are listed below.
If a CID 0444 FMI 12 occurs and the SMR is activated, then the engine stops cranking.
If a CID 0444 FMI 12 occurs and the SMR is not activated, then the engine can not crank or the engine can not start. If the engine is already running, then the engine continues to run.The GSC+ treats a CID 0444 FMI 12 as an alarm fault. Active alarm faults are shown on the display when the "Alarm Codes" key is pressed. The ECS can 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 0444 FMI 12 or the troubleshooting procedure is for an inactive CID 0444 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 0444 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 0444 FMI 12 is displayed as an active diagnostic code or CID 0444 FMI 12 is displayed as an inactive diagnostic code.Results:
OK - The CID 0444 FMI 12 is active or the CID 0444 FMI 12 is inactive. Proceed to test step 2.
NOT OK - The CID 0444 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. The clamp should be in place. The cable should not be damaged.Results:
OK - The cable is firmly seated in the connector. The clamp is in place. The cable is not damaged. Reassemble the relay module to the GSC+. Proceed to test step 3.
NOT OK - One or more of the components are