ALTERNATOR GP-CHARGING 1321186 - Caterpillar

Illustration 1 g01118659
Front Wheel Assist SolenoidThis diagnostic code is recorded when the ECM reads the voltage of the front wheel assist solenoid circuit as above normal (short to +V).The possible causes of this diagnostic code are:
The signal circuit is shorted to +V.
The ECM has failed. This is unlikely.System Response:The results of this diagnostic code are:
Conveyor diagnostic lamp on the machine operator's station will be ON.
Traction assist will not turn OFF.Note: Ensure that the diagnostic code CID 200 FMI F03 for the front wheel assist solenoid is on hold and that the diagnostic code present indicator on the ECM display is ON.Test Step 1. Check Solenoid Signal Circuit For Short To +V
Turn the key start switch to the OFF position.
Disconnect the machine harness from the front wheel assist solenoid.
Disconnect the machine harness connector from the ECM.
At the machine harness ECM connector, measure the resistance from the energize signal circuit at ECM contact 38 (wire P941-GN) to all other possible sources of +V. The possible sources of positive voltage are ECM contacts 1, 10, 11, 32, 33, 34, 36 37 and 40.Expected Result:Each resistance should be greater than 5000 ohms.Results:
OK - Each resistance measurement is greater than 5000 ohms. Proceed to Test Step 2.
NOT OK - One or more resistance measurement is less than 5000 ohms.Repair: There is a short in the machine harness. The short is between the energize signal circuit at ECM contact 38 (wire P941-GN) and the circuit with the low resistance measurement. Repair or replace the machine harness. Stop.Test Step 2. Check To See If Diagnostic Code Remains
Clean the contacts of the harness connectors.
Reconnect all harness connectors.
Turn the key start switch to the ON position.
Enter service mode 1 on the ECM three digit display. Clear all inactive diagnostic codes.
Operate the machine.
Check to see if the CID 200 FMI F03 diagnostic code for the front wheel assist solenoid is present (diagnostic code present indicator ON).Expected Result:The CID 200 FMI F03 diagnostic code for the front wheel assist solenoid is not present.Results:
OK - The CID 200 FMI F03 diagnostic code for the front wheel assist solenoid is not present. The machine harness and the ECM are operating properly.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.
NOT OK - The CID 200 FMI F03 diagnostic code for the front wheel assist solenoid is still present.Repair: It is unlikely that the ECM has failed. Exit this procedure and perform this procedure again. Refer to the Electrical System Schematic for this machine and check all involved wiring harness connectors and wiring. Ensure that the connector contacts are clean and in good condition. Ensure that all machine harness wiring is intact and in good condition. If the cause of this diagnostic code is not found, replace the ECM. See Testing and Adjusting, "Electronic Control Module (ECM) - Replace" in this manual. Stop.