Inspection and Verification

Inspection and Verification
1. Verify the customer concern.
2. Verify the stop lamps operate correctly by pressing and releasing the brake pedal with the ignition switch in the OFF position. If the stoplamps do not operate correctly, refer to Lighting and Horns. If the stoplamps operate correctly, proceed to the next step.
3. Verify the base brake system operates correctly. If any concerns are present, address them before continuing with any ABS concerns. If the stoplamps operate correctly, proceed to the next step.
4. Visually inspect for obvious signs of mechanical or electrical damage.

Visual Inspection Chart

Visual Inspection Chart:

5. If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step.

6. 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).

7. 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 (Module Communications Network), No Power To The Scan Tool, to diagnose no communication with the scan tool.
8. 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 Information Bus (Module Communications Network) to diagnose no response from the powertrain control module (PCM).
9. Carry out the network test.
^ If the scan tool responds with no communication for one or more modules, refer to Information Bus (Multiplex Communications Network).
^ If the network test passes, retrieve and record continuous memory diagnostic trouble codes (DTCs).
10. Clear the continuous DTCs and carry out the self-test diagnostics for the ABS module and the instrument cluster.
11. If the DTCs retrieved are related to the concern, go to the Anti-Lock Brake System (ABS) Module Diagnostic Trouble Code (DTC) Chart or the Instrument Cluster Diagnostic Trouble Code (DTC) Chart. For all other DTCs, refer to Body Control Systems (Multifunction Electronic Control Module). Anti-Lock Brake System (ABS) Module Diagnostic Trouble Code (DTC) Chart Instrument Cluster Diagnostic Trouble Code (DTC) Chart
12. If no DTCs related to the concern are retrieved, GO to Symptom Chart. Anti-Lock Control - Traction Control and Stability Assist