Visual Inspection

Ensure master cylinder reservoir is full and parking brake is fully released. Inspect wheel speed sensors and brakelines for damage. Inspect wheel bearings for looseness or damage. Repair items as necessary. Ensure all ABS system fuses are okay. See WIRING DIAGRAM . Check ABS warning indicator bulb. Check for damage to wiring harness. Check for loose or corroded connectors. Make necessary repairs.
WARNING: Circuits between ABCM and each WSS are twisted to ensure proper shielding. If any circuit repair is made, ensure wiring is twisted at intervals of one turn per inch (25 mm).
If problem remains after inspection, retrieve trouble codes. See RETRIEVING DIAGNOSTIC TROUBLE CODES . If DTCs are retrieved, go to ANTI-LOCK BRAKE CONTROL MODULE (ABCM) DTC DEFINITIONS table. Perform appropriate TEST. If ABS control module cannot be accessed using NGS scan tester, see MODULE COMMUNICATIONS NETWORK article in the ACCESSORIES & EQUIPMENT section.