Visual Inspection

Verify customer concern by operating system.
Ensure master cylinder reservoir is full and parking brake is fully released. Inspect HCU, ABS relay, brake position switch, wheel speed sensors and brake lines for damage. Inspect wheel bearings for looseness or damage. Repair items as necessary. Ensure all ABS system fuses are okay. See WIRING DIAGRAMS . Check ABS warning indicator bulb. Check for damage to wiring harness. Check for loose or corroded connectors. Make necessary repairs.
Inspect TCS module, ABS sensor, TCS switch, steering wheel rotation sensor, brake booster solenoid and release switch, primary and secondary pressure transducers, yaw rate sensor and accelerometer for damage.
Inspect fuses F11 and F21 in battery junction box. Inspect fuses F20, F30, F36, F38, F54 and F59 in central junction box.
If problem remains after inspection, retrieve trouble codes. See RETRIEVING DIAGNOSTIC TROUBLE CODES . If DTCs are retrieved, go to ABS DIAGNOSTIC TROUBLE CODE DEFINITIONS table. Perform appropriate test. If no DTCs related to concern are retrieved, see SYMPTOM DIAGNOSIS . If ABS control module cannot be accessed using scan tool, see appropriate MODULE COMMUNICATIONS NETWORK article in ACCESSORIES & EQUIPMENT.