Red Brake Warning Light Malfunction

NOTE: For connector terminal identification and wiring diagrams, see BODY CONTROL COMPUTER - INTRODUCTION article. Perform VERIFICATION TEST VER-1A after each repair.

CAUTION: Always turn ignition switch to OFF position prior to disconnecting any module connector.

If vehicle is equipped with ABS, see appropriate ANTI-LOCK article in BRAKES. On non-ABS vehicles, ensure park brake pedal is fully released. If park brake will not release, repair as needed. Turn ignition on. If brake warning light is illuminated, go to next step. If brake warning light is not illuminated, go to step 6 .
Ensure brake fluid reservoir is full. Disconnect brake fluid level switch connector and observe brake warning light. If brake warning light is not illuminated, replace brake fluid level switch. If brake warning light is illuminated, go to next step.
Disconnect park brake switch connector located on park brake pedal bracket. If brake warning light is not illuminated, replace park brake switch. If brake warning light is illuminated, go to next step.
Turn ignition off. Disconnect information center connector. Remove ignition key. Turn off all lights and accessories. Close all doors. Using external ohmmeter, measure resistance between ground and at information center connector terminal No. 9 (Gray/Black wire). If resistance is 5 ohms or more, replace information center. If resistance is less than 5 ohms, go to next step.
Disconnect ignition switch connector. See Figure . Using external ohmmeter, measure resistance between ground and at information center connector terminal No. 9 (Gray/Black wire). If resistance is 5 ohms or more, replace ignition switch. If resistance is less than 5 ohms, repair Gray/Black wire for short to ground.
Crank engine and observe brake warning light. If brake warning light does not illuminate, go to step 11 . If brake warning light illuminates, go to next step.
Apply park brake. If brake warning light does not illuminate, go to step 10 . If brake warning light illuminates, go to next step.
Turn ignition off. Disconnect brake fluid level switch connector. Connect jumper wire between switch connector terminals. Turn ignition on. If brake warning light illuminates, replace brake fluid level switch. If brake warning light does not illuminate, go to next step.
Disconnect jumper wire. Connect jumper wire between chassis ground and brake fluid level switch connector terminal No. 2 (Gray/Black wire). If brake warning light does not illuminate, repair open Gray/Black wire. If brake warning light illuminates, repair open brake fluid level switch ground circuit (Black wire).
Disconnect parking brake switch connector located on parking brake pedal bracket. Connect jumper wire between chassis ground and switch connector. If brake warning light illuminates, replace parking brake switch. If brake warning light does not illuminate, repair open Gray/Black wire between parking brake switch and junction block.
Turn ignition off. Disconnect ignition switch connector. See Figure . Using external ohmmeter, measure resistance between ground and ignition switch connector terminal No. 1 (Black wire). If resistance is 5 ohms or more, repair open Black wire. If resistance is less than 5 ohms, go to next step.
Reconnect ignition switch connector. Turn ignition on. Backprobing ignition switch connector, connect jumper wire between ground and ignition switch connector terminal No. 2 (Gray/Black wire). If brake warning light illuminates, replace ignition switch. If brake warning light does not illuminate, go to next step.
With jumper wire connected, disconnect information center connector. Remove ignition key. Turn off all lights and accessories. Close all doors. Using external ohmmeter, measure resistance at terminal No. 9 (Gray/Black wire) on information center connector. If resistance is 5 ohms or more, repair open Gray/Black wire. If resistance is less than 5 ohms, go to next step.
Remove and inspect red brake warning light bulb. Replace as needed. If bulb is okay, replace information center.