Inspection and Verification
Power Liftgate
Inspection and Verification
1. Verify the customer concern.
2. The battery voltage must be at normal operating levels in order for the power liftgate to open and close correctly. Make sure the battery and charging systems are operating correctly before proceeding with the power liftgate diagnosis.
3. Visually inspect for obvious signs of mechanical and electrical damage. Refer to the following chart.
Visual Inspection Chart:
4. If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step.
5. 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).
6. 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 Information Bus, No Power To The Scan Tool, to diagnose no power to the scan tool.
7. If the scan tool does not communicate with the vehicle:
- verify the ignition key is in the ON position.
- verify the scan tool operation with a known good vehicle.
- refer to Information Bus to diagnose no response from the Liftgate/Trunk Module (LTM) or Smart Junction Box (SJB).
8. Carry out the network test.
- If the scan tool responds with no communication for one or more modules, refer to Information Bus.
- If the network test passes, retrieve and record Continuous Memory Diagnostic Trouble Codes (CMDTCs).
9. NOTE: Carrying out the LTM initialization procedure will resolve concerns where the power liftgate has lost position or was not initialized correctly. For information, refer to Power Liftgate Initialization Programming and Relearning.
Clear the CMDTCs and carry out the self-test diagnostics for the power liftgate or SJB.
10. If the DTCs retrieved are related to the concern, go to the Liftgate/Trunk Module (LTM) DTC Chart or the Smart Junction Box (SJB) DTC Chart. For all other DTCs, refer to Body Control Systems.
11. If no DTCs related to the concern are retrieved, GO to Symptom Chart. Symptom Related Diagnostic Procedures