TUBE ASSEM. 3N6978 - Caterpillar

Illustration 1 g01355453
Schematic of the start relay magnetic switch
This diagnostic code is associated with the start relay magnetic switch. The "FMI 03" means that the Power Train/Chassis Electronic Control Module (ECM) has determined that the voltage of the relay circuit is above normal.The possible causes of the diagnostic code are listed:
The relay has failed.
The relay circuit is shorted to the +battery circuit.
The ECM has failed. This is unlikely.Note: The following test procedure may create other diagnostic codes. Ignore these created diagnostic codes and clear these diagnostic codes when the original diagnostic code has been corrected. Ensure that the diagnostic code of "CID 0444 FMI 03" is active before performing this procedure.Note: Use the 146-4080 Digital Multimeter for the measurements in this procedure.System Response:When this diagnostic code is active, the starter motor is always engaged and the transmission will select neutral.Test Step 1. CHECK THE RELAY CIRCUIT FOR A SHORT TO A +BATTERY CIRCUIT
Turn the key start switch and the battery disconnect switch to the OFF position.
Disconnect the machine harness connector from the relay and connectors J1 and J2 from the ECM.
At the machine harness connector for the ECM, measure the resistance from contact J2-7 (wire 306-GN(Green)) to all contacts that are used in the machine harness connectors for the ECM. Expected Result:Each resistance measurement is greater than 5 ohms.Results:
YES - Each resistance measurement is greater than 5 ohms. The machine harness is correct. Proceed to Test Step 2.
NO - Each resistance measurement is not greater than 5 ohms. There is a short in the machine harness. The short is between J2-7 (wire 306-GN(Green)) and the circuit that has a low resistance measurement. Repair: Repair the machine harness or replace the machine harness.STOPTest Step 2. CHECK IF THE DIAGNOSTIC CODE REMAINS
Inspect the contacts and clean the contacts of the harness connectors.
Reconnect all harness connectors.
Turn the battery disconnect switch and the key start switch to the ON position.
Operate the machine.
Determine if the "CID 0444 FMI 03" is active. Expected Result:The "CID 0444 FMI 03" is active.Results:
YES - The "CID 0444 FMI 03" is active. The problem has not been corrected. The ECM may have failed.Repair: It is unlikely that the ECM has failed. Exit this procedure and perform this procedure again. If the cause of the diagnostic code is not found, replace the ECM. Refer to Systems Operation, Troubleshooting, Testing and Adjusting, "Electronic Control Module (ECM) - Replace".STOP
NO - The "CID 0444 FMI 03" is not active. The problem does not exist at this time.Repair: The initial diagnostic code was probably caused by a poor electrical connection or a short at one of the harness connectors that was disconnected and reconnected. Resume normal machine operation.STOP