Inspection And Verification
CAUTION:
Diagnosis by substitution from a donor vehicle is NOT
acceptable. Substitution of control modules does not guarantee confirmation of a fault, and may also cause additional faults in the vehicle being tested and/or the donor vehicle.
NOTE:
Check and rectify basic faults before beginning diagnostic routines involving pinpoint tests.
- Verify the customer concern.
- Visually inspect for obvious signs of mechanical or electrical damage.
Visual Inspection
Mechanical Electrical - Tire condition, pressures, etc
- Driveline components (correct installation, damage, etc)
- Engine components (correct installation, damage, etc)
- Transmission components (correct installation, damage, etc)
- Suspension components (correct installation, damage, etc)
- Fuses
- Harnesses/Connectors
- Terrain response module
- Engine Control Module (ECM)
- Transmission Control Module (TCM)
- Transfer case control module
- Anti-lock Braking (ABS) control module
- Rear differential control module
- Dynamic suspension control module
- Controller Area Network (CAN) circuits
- If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step.
- If the cause is not visually evident, verify the symptom and refer to the Symptom Chart, alternatively check for Diagnostic Trouble Codes (DTCs) and refer to the DTC Index.