Initial Inspection and Diagnostic Overview

Special Tools:

Inspection and Verification

NOTE: If a new anti-lock brake system (ABS) module is installed, it must be configured. If equipped with stability assist, the ABS module must also be calibrated. Follow the diagnostic 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 Transmission and Drivetrain. If the PRNDL operates correctly, proceed to the next step.
4. Visually inspect for obvious signs mechanical or electrical damage:





Visual Inspection Chart

5. If the cause is not visually evident, connect the diagnostic tool to the data link connector and select the vehicle to be tested from the diagnostic tool menu. If the diagnostic tool does not communicate with the vehicle:
^ check that the program card is correctly installed.
^ check the connections to the vehicle.
^ check the ignition switch position.
6. If the diagnostic tool still does not communicate with the vehicle, refer to the diagnostic tool operating manual.

NOTE: If equipped with stability assist, the vehicle must be at a complete standstill when carrying out the self-test. Any movement of the vehicle during the self-test may result in false DTCs being set.

7. Carry out the diagnostic tool data link test. If the diagnostic tool responds with:
^ CAN, ISO or UBP circuit fault; all electronic control units no response/not equipped, refer to Module Communications Network.
^ No response/not equipped for the ABS module, Go to Pinpoint Test A. Test A
^ System passed, retrieve and record the continuous diagnostic trouble codes (DTCs), erase the continuous DTCs and carry out self-test diagnostics for the ABS module.
8. If the DTCs retrieved are related to the concern, go to the Anti-Lock Brake System (ABS) Module Diagnostic Trouble Code (DTC) Index to continue diagnostics. ABS Control Module Diagnostic Trouble Code (DTC) Index
9. If no DTCs related to the concern are retrieved, GO to Symptom Chart to continue diagnostics.

NOTE: The need to recalibrate the module is indicated by the active/fail lamp flashing. There are other service actions that can require recalibration when there is no flashing lamp. The lamp will flash after clearing the DTCs that are indicated in the ABS module calibration list.

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

NOTE: For a complete master list of DTCs, refer to Module Communications Network.