KIT-CENTER SECTION 9T8951 - Caterpillar

Illustration 1 g03111036
Schematic of the key start switchThe Power Train Electronic Control Module (ECM), activates the start relay when the key start switch is in the START position and the transmission direction control switch is in the NEUTRAL position. The ECM detects a failure in the circuit for the start relay and the electrical system. If CID 0444, or CID 0168 are present the diagnostic code must be corrected before performing the following procedure.Test Step 1. CHECK THE KEY START SWITCH IN THE START POSITION
Make sure that CID 0444 or CID 0168 faults do not exist. If a fault exists, correct the fault before proceeding.
Move the disconnect switch and the key start switch to the OFF position.
Disconnect the machine harness connector from the ECM.
Move the disconnect switch to the ON position.
Move and hold the key start switch in the START position.
At the machine harness connector for the ECM, measure the voltage between contact J2-1 (wire 307-OR) and frame ground.Expected Result: Supply voltage should be present.Results:
YES - Supply voltage is present. Proceed to Test Step 2.
NO - Supply voltage is NOT present. The key start switch or the machine harness (wire 307-OR) has failed.Repair: Repair the machine harness or replace the machine harness. Repair the key start switch or replace the key start switch.STOPTest Step 2. CHECK THE KEY START SWITCH IN THE OFF POSITION
The machine harness remains disconnected from the ECM.
Move the key start switch to the OFF position.
At the machine harness connector for the ECM, measure the voltage between contact J2-1 (wire 307-OR) and frame ground.Expected Result: Supply voltage is not present.Results:
YES - Supply voltage is not present. The harness circuit operates correctly. The ECM may have failed.Repair: The ECM is unlikely to fail. Exit this procedure and perform this procedure again. If the cause of the diagnostic code is not found, replace the ECM. Refer to Troubleshooting, Testing, and Adjusting, "Electronic Control Module (ECM) - Replace".STOP
NO - Supply voltage is present. The key start switch or the machine harness (wire 307-OR) has failed.Repair: Repair the machine harness or replace the machine harness. Repair the key start switch or replace the key start switch.STOP