Inspection and Verification

Anti-Lock Control

Inspection and Verification

WARNING: Before servicing a vehicle equipped with a fire suppression system, depower the system by following the procedure in Fire Suppression System. Failure to follow the instructions may result in serious personal injury Procedures.

1. Verify the customer concern.

2. Verify the stoplamps operate correctly by applying and releasing the brake pedal with the ignition switch in the OFF position. If the stoplamps do not operate correctly, refer to Diagnosis and Testing in Exterior Lighting Testing and Inspection. If the stoplamps operate correctly, proceed to the next step.

3. Visually inspect for obvious signs of mechanical and electrical damage.

Visual Inspection Chart





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 Module Communications Network Testing and Inspection, 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 key is in the ON position.

- verify the scan tool operation with a known good vehicle.

- refer to Module Communications Network Testing and Inspection 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 Module Communications Network Testing and Inspection to diagnose the no communication concern.

- If the network test passes, retrieve and record continuous memory DTCs.

8. Clear the continuous DTCs and carry out the self-test diagnostics for the ABS module.

9. If the DTCs retrieved are related to the concern, go to the ABS Module DTC Chart Diagnostic Trouble Code Tests and Associated Procedures. For all other DTCs, refer to the Master DTC Chart in Multifunction Electronic Modules Testing and Inspection.

10. If no DTCs related to the concern are retrieved, GO to Symptom Chart. Symptom Related Diagnostic Procedures