Inspection and Verification

Inspection and Verification

NOTE: If a new ABS module or hydraulic control unit (HCU) is installed, it must be configured. Follow the scan tool directions.

1. Verify the customer concern.
2. Verify the stoplamps 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 that the PRNDL operates correctly on the instrument cluster. If the PRNDL does not operate correctly, refer to Instrument Panel, Gauges and Warning Indicators. If the PRNDL operates 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 Configuration) to diagnose no response from the 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 DTCs.

10. NOTE: The vehicle must be at a complete standstill and on a level surface while carrying out the self-test. Any movement of the vehicle during the self-test may result in false DTCs being set.

Clear the continuous DTCs and carry out the self-test diagnostics for the ABS module.
11. If the DTCs retrieved are related to the concern, go to ABS Module DTC Chart. Diagnostic Trouble Code Tests and Associated Procedures For all other DTCs, refer to Body Control Systems (Multifunction Electronic Control Module).
12. If no DTCs related to the concern are retrieved, GO to Symptom Chart. Symptom Related Diagnostic Procedures

NOTE: Always retrieve the continuous DTCs after running the self-test.

NOTE: For a complete master list of DTCs, refer to Body Control Systems (Multifunction Electronic Control Module).

NOTE: If DTC B2900, C1805 and U0001 are set at the same time, diagnose the concern for U0001 first.