770G and 772G Off-Highway Truck/Tractors Caterpillar

CHECK THE INDICATOR LAMP.

1. Turn the key start switch to the ON position.

2. Observe the indicator lamp.

Expected Result:

The indicator lamp is ON position.

Results:

• OK - The indicator lamp is ONposition. The harness circuit (wire 676-PU(Purple)) is shorted to the + battery. The harness has failed.

Repair: Repair the harness or replace the harness.

STOP.

• NOT OK - The indicator lamp is NOT ONposition. The harness circuit is correct. The ECM may have failed.

Repair: It is unlikely that the ECM has failed. Exit this procedure and perform this procedure again. Exit this procedure and perform this procedure again. If the cause of the diagnostic code is not found, contact your dealership Technical Communicator for possible consultation with Caterpillar. This consultation may greatly reduce repair time. If the ECM requires replacement, refer to Testing and Adjusting, "Electronic Control Module (ECM) - Replace" section of this manual for additional information.

STOP.