Inspection And Verification
Four Wheel Drive (4WD) Systems - Electronic Shift
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 Information Bus, 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 Information Bus 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 Information Bus.
- If the network test passes, retrieve and record Continuous Memory Diagnostic Trouble Codes (CMDTCs).
8. If the DTCs retrieved are related to a driveability concern, refer to Computers and Control Systems Information before proceeding to the next step.
9. If the DTCs retrieved are related to the concern, go to the 4X4 Control Module DTC Chart to continue diagnosis. [1][2]Diagnostic Trouble Code Descriptions
10. If the DTCs retrieved are not found in the 4X4 Control Module DTC Chart, refer to the DTC Chart in Body Control Systems. [1][2]Diagnostic Trouble Code Descriptions Diagnostic Trouble Code (DTC) Chart
11. If no DTCs related to the concern are retrieved, GO to Symptom Chart - Electronic Shift or GO to Symptom Chart - NVH. Symptom Chart - Electronic Shift Symptom Chart - NVH