ABS Light: Testing and Inspection

Each of the lamps depends upon a hard wired circuit input to the instrument cluster for proper operation. The following procedures will help to diagnose conditions that may cause an inoperative hard wired lamp circuit condition.

WARNING: ON VEHICLES EQUIPPED WITH AIR-BAGS, REFER TO AIR BAGS AND SEAT BELTS/AIR BAGS BEFORE ATTEMPTING ANY STEERING WHEEL, STEERING COLUMN, OR INSTRUMENT PANEL COMPONENT DIAGNOSIS OR SERVICE. FAILURE TO TAKE THE PROPER PRECAUTIONS COULD RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL INJURY.

Anti-Lock Brake System Lamp
The diagnosis found here addresses an inoperative Anti-lock Brake System (ABS) lamp condition. If the ABS lamp stays on with the ignition switch in the ON position, or comes on and stays on while driving. If no ABS problem is found, the following procedure will help locate a short or open in the ABS lamp circuit. For complete circuit descriptions, refer to Instrument Cluster.

1. Check the fused ignition switch output (RUN/START) fuse in the fuse block module. If OK, go to Step 2. If not OK, repair the shorted circuit or component as required and replace the faulty fuse.

2. Turn the ignition switch to the ON position. Check for battery voltage at the fused ignition switch output (RUN/START) fuse in the fuseblock module. If OK, go to Step 3. If not OK, repair the open fused ignition switch output (RUN/START) circuit to the ignition switch as required.

3. Turn the ignition switch to the OFF position. Disconnect and isolate the battery negative cable. Remove the instrument cluster. Connect the battery negative cable. Turn the ignition switch to the ON position and within five seconds check for continuity between the ABS warning indicator driver circuit cavity of the instrument cluster wire harness connector A and a good ground. There should be continuity for five seconds after ignition ON, and then an open circuit. If OK, replace the faulty bulb. If not OK, go to Step 4.

4. Turn the ignition switch to the OFF position. Disconnect and isolate the battery negative cable. Disconnect the Controller Anti-lock Brake (CAB) wire harness connector. Check for continuity between the ABS warning indicator driver circuit cavity of the instrument cluster wire harness connector A and a good ground. There should be no continuity. If OK, go to Step 5. If not OK, repair the shorted ABS warning indicator driver circuit as required.

5. Check for continuity between the ABS warning indicator driver circuit cavities of the instrument cluster wire harness connector A and the CAB wire harness connector. There should be continuity. If not OK, repair the open ABS warning indicator driver circuit as required.