Diagnosis & Testing: Self-Diagnostics
- Perform a visual inspection. See VISUAL INSPECTION . Apply parking brake. Place gear selector in Park. Block drive wheels. Turn off all electrical loads (radio, lights, A/C, blower fans, etc.). Close all doors (front doors, rear doors, hood, trunk lid).
- Turn ignition on. Observe ABS warning light on instrument cluster. If warning light illuminates for a few seconds and goes out, ABS is operating properly. If warning light illuminates and remains on, go to next step. If warning light does not illuminate, go to ABS WARNING LIGHT DOES NOT ILLUMINATE WITH IGNITION ON under SYMPTOM TESTS.NOTE: Certain DTCs require vehicle to be driven in order for warning light to turn on. Other DTCs will turn warning light on each time engine is started.
- Start engine. Drive vehicle, if necessary. Observe ABS warning light. If warning light is on, a hard fault is present. Go to next step. If warning light is off and an ABS symptom exists, fault may be intermittent. Go to TROUBLE SHOOTING. If warning light is off and no ABS symptom exists, ABS is operating properly. Check non-ABS portion of brake system for possible cause of problem. See appropriate DISC & DRUM article for diagnosis of conventional braking system.
- Retrieve Diagnostic Trouble Codes (DTCs). See RETRIEVING TROUBLE CODES . Record all DTCs. Perform appropriate test for first DTC retrieved. See DIAGNOSTIC TROUBLE CODE (DTC) IDENTIFICATION table. After all DTCs have been retrieved and faults have been corrected, clear DTCs. See CLEARING TROUBLE CODES .