Inspection and Verification
Electronic Locking Differential (ELD) System
Inspection and Verification
1. Verify the customer concern.
2. Visually inspect for obvious signs of mechanical or electrical damage.
Visual Inspection Chart
3. If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step.
4. NOTE: Make sure to use the latest scan tool software release.
If the cause is not visually evident, connect the scan tool to the Data Link Connector (DLC).
5. NOTE: The Vehicle Communication Module (VCM) LED prove out confirms power and ground from the DLC are provided to the VCM.
If the scan tool does not communicate with the VCM:
- check the VCM connection to the vehicle.
- check the scan tool connection to the VCM.
- refer to Module Communications Network Testing and Inspection, No Power To The Scan Tool, to diagnose no power to the scan tool.
6. If the scan tool does not communicate with the vehicle:
- verify the ignition is ON.
- verify the scan tool operation with a known good vehicle.
- refer to Module Communications Network Testing and Inspection to diagnose no response from the PCM.
7. Carry out the network test.
- If the scan tool responds with no communication for one or more modules, refer to Module Communications Network Testing and Inspection.
- If the network test passes, retrieve and record Continuous Memory Diagnostic Trouble Codes (CMDTCs).
8. Clear the continuous DTCs and carry out the self-test diagnostics for the PCM and TCCM.
9. If the DTCs retrieved are related to a driveability concern, refer to Computers and Control Systems before proceeding to the next step.
10. If the DTCs retrieved are related to the concern, go to the Transfer Case Control Module (TCCM) - Electronic Locking Differential (ELD) System DTC Chart. Diagnostic Trouble Code Tests and Associated Procedures
11. If no DTCs related to the concern are retrieved, GO to Symptom Chart - Electronic Locking Differential (ELD) System. Symptom Related Diagnostic Procedures