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. If the cause is not visually evident, connect the diagnostic tool to the data link connector and select the vehicle to be tested from the diagnostic tool menu. If the diagnostic tool does not communicate with the vehicle:
^ check that the program card is correctly installed (if using NGS+).
^ check the connections to the vehicle.
^ check the ignition switch position.
5. If the diagnostic tool still does not communicate with the vehicle, refer to the diagnostic tool operating manual.
6. Carry out the data link diagnostics test. If the diagnostic tool responds with:
^ SCP+, SCP-, UBP, CAN or ISO circuits fault; all electronic control units no response/not equipped, refer to Information Bus (Multiplex Communications Network).
^ No response/not equipped for powertrain control module (PCM). Refer to Information Bus (Module Communications Network) to diagnose module communication problems.
^ No response/not equipped for 4WD control module, GO to Pinpoint Test G. Test G: No Communication With The Four Wheel Drive (4WD) Control Module (GEM)
^ System passed, retrieve and record the continuous diagnostic trouble codes (DTCs), erase the continuous DTCs and carry out the self-test diagnostics for the 4WD control module.
7. If the DTCs retrieved are related to the concern, go to the Four Wheel Drive (4WD) Diagnostic Trouble Code (DTC) Index to continue diagnostics. Diagnostic Trouble Code Tests and Associated Procedures
8. If no DTCs related to the concern are retrieved, GO to the Symptom Chart. Symptom Chart - Electronic Shift