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| Illustration 1 | g00842126 |
Schematic of the Circuit for the Harness Code Plug | |
This diagnostic code is recorded when a valid harness code is not received from the Caterpillar Monitoring System.
The possible causes of this diagnostic code are listed:
- The data link wire between the power train ECM and the Caterpillar Monitoring System has failed.
System Response:
The machine response is listed:
- Machine response is not affected.
Note: Ensure that the diagnostic code indicator is active and that the diagnostic code is active.
Test Step 1. CHECK FOR A OPEN CIRCUIT.
- Disconnect connector J1 from the power train ECM.
- Disconnect the harness from rear of Caterpillar Monitoring System.
- Check the continuity of wire (892-BR) and wire (893-GN).
Expected Result:
The resistance is less than 5 Ohms on each circuit.
Results:
- Yes - The resistance is less than 5 Ohms on each circuit. Proceed to test step 2.
- NO - The resistance is greater than 5 Ohms.
Repair: The harness has failed. Repair the harness or replace the harness.
Stop.
Test Step 2. CHECK FOR A SHORT IN THE HARNESS.
- The two connectors remain disconnected.
- Check the continuity between wire (892-BR) and wire (893-GN).
Expected Result:
The resistance is greater than 5000 Ohms.
Results:
- YES - The resistance is greater than 5000 Ohms. Proceed to test step 3.
- NO - The resistance is less than 5000 Ohms.
Repair: The harness has failed. The two wires are shorted in the harness. Repair the harness or replace the harness.
Stop.
Test Step 3. CHECK IF THE DIAGNOSTIC CODE REMAINS.
- Reconnect J1 to the power train ECM.
- Reconnect the harness connector to the Caterpillar Monitoring System.
- Ensure that the diagnostic code is inactive.
Expected Result:
The diagnostic code is no longer active.
Results:
- YES - The diagnostic code is no longer active.
Repair: The diagnostic code no longer exists. The diagnostic code was caused by a loose connection.
Stop.
- NO - The diagnostic code remains active.
Repair: It is unlikely that the ECM has failed. Exit this procedure. Perform this test procedure again. If the cause of the diagnostic code is not found, replace the ECM. See Testing and Adjusting, "Electronic Control Module (ECM) - Replace".
Stop.