If your BMW doesn't start or get out of Park, the culprit could be a bad brake light switch. You may think that because the brake lights work, the brake light is working properly, but that's not always true. Checking the brake lights can be misleading.
A failed brake light switch on a BMW can trigger a number of warning lights, errors and can even prevent the transmission from shifting gears. Common symptoms of a faulty brake light switch on a BMW include:
- The brake light stays on
- Shifter won't' move out of the park position
- Brake lights don't work
- Transmission stuck in limp, safe home mode
- DSC light comes on
- Car may not turn on
- Brake lights stay on all the time
- Cruise control doesn't work
- ABS light stays on
What you will need
- Park the BMW on level ground.
- Set the parking brakes and turn off the ignition.
- Access the panel under the dashboard on the driver's side. This is the black panel right above the brake and gas pedals, also known as the kick panel.
- Remove the Philips screws. In some BMWs, you may have Torx screws.
- Locate the brake light switch above the brake pedal.
- Press the connector and unplug the wire harness from the BMW brake light switch.
- Remove the brake light switch from the bracket. Start by pressing the brake pedal. There will be one or two tabs that you need to press, which will release the brake light switch. If your brake light switch has a red or white-collar, you will need to slide that out, then press the tabs and release the brake light switch.
If you are still getting an error message or your brake lights still don't work, you will need to scan your BMW for codes.
Most generic OBD2 scanners will not be able to read fault codes from the BMW brake system, but you can use a multi-system scanner such as Foxwell NT510 for BMW.
If your BMW brake lights don't work, or you get Brake Light Circuit Failure warning, brake lights are always on; the shifter won't move out of the park chances are that you have a bad brake light switch.
- It is recommended to disconnect the battery negative terminal as well. Just in case there is a short while you work under the dash.
- Brake light fails error message.
- Brake light circuit error message
- Brake light on
- ABS or DSC light on