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Inspection and Verification

  1. Verify the customer concern.
  2. Visually inspect the following for obvious signs of electrical damage.
    INSPECTION AND VERIFICATION CHART

    Electrical
    • Battery junction box (BJB) fuse(s):
      • 17 (40A) (no communication with anti-lock brake system [ABS] module)
      • 21 (10A) (no communication with powertrain control module [PCM])
      • 27 (20A) (no communication with four-wheel drive [4WD] control module)
      • 39 (30A) (no communication with ABS module)
      • 39 (15A) (no communication with PCM)
    • Smart junction box (SJB) fuse(s):
      • 8 (10A) (no communication with restraints control module [RCM])
      • 9 (5A) (no communication with instrument cluster)
      • 10 (10A) (no communication with instrument cluster, 4WD control module)
      • 11 (10A) (no communication with SJB)
      • 20 (10A) (no communication with ABS module)
      • 28 (15A) (no power to the 4WD control module)
      • 29 (20A) (no power to the IDS or equivalent tester)
      • 33 (5A) (no communication with the instrument cluster)
    • Data link connector (DLC)
    • Circuitry
  3. If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step.
    NOTE:
    • Make sure to use the latest IDS or equivalent tester software release.
  4. If the cause is not visually evident, connect the IDS or equivalent tester to the DLC.
    NOTE:
    • The vehicle communication module (VCM) LED prove-out confirms power and ground from the DLC are provided to the VCM.
    • If the IDS or equivalent tester does not communicate with the VCM:
    NOTE:
    • During the network test, the IDS or equivalent tester will first attempt to communicate with the PCM, after establishing communication with the PCM, the IDS or equivalent tester will then attempt to communicate with all other modules on the vehicle.
  5. Carry out the network test:
  6. If the DTCs retrieved are related to the concern, go to that module's Diagnostic Trouble Code (DTC) Index. For all other DTCs, see Diagnostic Trouble Code (DTC) Index -- B, C And U Codes , .
  7. If no DTCs related to the concern are retrieved, See SYMPTOM TROUBLESHOOTING CHART - COMMUNICATIONS NETWORK , .