MOTOR GP- 4532786 - Caterpillar

Illustration 1 g03796117
Table 1
Troubleshooting Test Steps Values Results
1. Inspect the Electrical Connectors and the Wiring
A. Remove electrical power from the ECM.
B. Thoroughly inspect any of the connectors that are associated with the lamp circuits. Refer to the Schematic of the engine for connector locations. Refer to Troubleshooting, "Electrical Connectors - Inspect".
C. Perform a 45 N (10 lb) pull test on each of the wires for the lamp circuits.
D Check the harness and the wiring for abrasion and for pinch points from the dash display back to the ECM.
Connectors
Results: The harness and connectors appear to be in good repair.
Proceed to Test Step 2
Results: The connectors and/or wiring need repair.
Repair: The wiring and/or the connectors. Replace parts, if necessary. Ensure that all of the seals are properly in place and ensure that the connectors are coupled.
If the problem is not resolved, proceed to Test Step 2.
2. Check for Proper Operation of the Lamp Circuits
A. Connect Cat® Electronic Technician (Cat ET) to the service tool connector.
B. Restore electrical power to the ECM.
C. Select the "Override Parameters" option from the "Diagnostic Tests" on Cat ET.
D. Use the correct override parameter to power the circuit for the suspect lamp.
E. Remove electrical power from the ECM.
Lamp circuits
Results: The suspect lamp illuminates when the override is on.
Repair: There does not appear to be a problem with the lamp circuit at this time. The problem may have been related to a faulty connection in the harness. Carefully reinspect the connectors and wiring. Refer to Troubleshooting, "Electrical Connectors - Inspect"
Results: The suspect lamp does not illuminate when the override is on.
Repair: Inspect the lamp and the lamp socket for the suspect circuit. If either of the components are questionable, replace the component. Retest the circuit. If the problem persists or if the components of the lamp assembly appear to be in good repair.
Proceed to Test Step 3.
3. Use the Override to Check the Wiring Harness
A. Remove the lamp for the suspect circuit from the lamp socket.
B. Connect a test lamp between the terminal that is for the driver circuit from the ECM and the −Battery terminal.
C. Restore electrical power to the ECM.
D. Use the override parameter in Cat ET to power the circuit for the suspect lamp.
E. Remove electrical power from the ECM.
Test Lamp
Results: The test lamp illuminates when the override is turned on.
Repair: Check for continuity between the negative terminal of the lamp socket and −Battery.
If the circuit is continuous, the lamp or the lamp socket is the cause of the problem. Replace the faulty lamp or the faulty lamp socket. Verify that the repair eliminates the original problem.
If the circuit is not continuous, there is a problem in the ground circuit for the lamp. Repair the ground circuit. Verify that the repair eliminates the original problem.
Results: The test lamp does not illuminate when the override is turned on.
Repair: There is a problem in the harness or in a connector. There may be a problem with the ECM.
Proceed to Test Step 4
4. Check for Proper Operation of