Anti-Lock Warning Light: Notes

1. Turn ignition on. ANTI-LOCK warning light should illuminate. Turn ignition switch to START position. Warning light should remain on and then go out after one second.
2. If warning light functions as specified, go next step. If warning light does not function as specified, see appropriate trouble shooting test:
   • ANTI-LOCK WARNING LIGHT INOPERATIVE.
   • ENGINE RUNNING, ANTI-LOCK WARNING LIGHT REMAINS ON.
   • IGNITION SWITCH IN ON POSITION (ENGINE NOT RUNNING), ANTI-LOCK WARNING LIGHT STAYS ON FOR APPROXIMATELY ONE SECOND, THEN SWITCHES OFF.
   • IGNITION SWITCH IN ON POSITION, ANTI-LOCK WARNING LIGHT FLASHES
   • IGNITION SWITCH TURNED TO START POSITION, WARNING LIGHT SWITCHES OFF IMMEDIATELY (DOES NOT REMAIN ON FOR ONE SECOND).
3. Test drive vehicle. If ABS light does not come on at low speed, go to next step. If ABS light comes on at low speed, motor relay, solenoid valve or wheel speed sensor malfunction is indicated. Go to step  6 . If insufficient braking force or ABS malfunction exists, go to next step. If none of listed symptoms exist, go to step  6 .
4. Check conventional brake system components for proper operation. Check for mechanical lock of hydraulic unit solenoid valve. Check for plugged hydraulic line in hydraulic unit. Repair or replace as necessary. If hydraulic unit is okay, go to next step.
5. Check for faulty wheel speed sensor. See WHEEL SPEED SENSOR TEST  under COMPONENT TESTING. Replace sensor as necessary. See WHEEL SPEED SENSOR  under REMOVAL & INSTALLATION. Inspect ABS ECU wiring. If testing indicates no mechanical or electrical failures, replace ABS ECU.
6. Enter ABS self-diagnostics, and retrieve DTCs. See RETRIEVING DTCS  under SELF-DIAGNOSTIC SYSTEM. If no DTCs are displayed, fault may be intermittent. Try to make malfunction reoccur. If no diagnostic output exists, check for faulty wiring harness between ABS ECU and self-diagnostic connector. Repair or replace as necessary.