Electrical Circuit

Turn ignition switch to START position and release to ON position. Red BRAKE warning light should come on in START position and go off in ON position. If Red BRAKE warning light stays on after bulb check, check brake fluid level, ensure parking brake is fully released and there are no leaks in hydraulic brake system. If Red BRAKE warning light does not come on, go to next step. If Red BRAKE warning light comes on and goes out after bulb check, Red BRAKE light is operating properly.
Turn ignition off. Connect a jumper wire (backprobe) between Body Control Module (BCM) 14-pin connector terminal No. 2 (Gray/Black wire) and chassis ground. Turn ignition on. Red BRAKE warning light should come on. If Red BRAKE warning light does not come on, refer to RED BRAKE WARNING LIGHT TEST in the appropriate BRAKE SYSTEM - ANTI-LOCK article.

If Red BRAKE warning light comes on, check for faulty brake warning switch or wiring between BCM and brake warning switch. Repair as necessary.