Brake Light Switch Failure
For the last two years, there has been an intermittent problem with my 1998 BMW 323is where the car computer will report a "brake light circuit" error. On numerous occasions I've parked the car, checked the lights, and seen nothing wrong. The bulbs all function, and the brakes themselves are in excellent condition (I just had all-new pads and rotors installed a month ago).
I googled the problem a bit recently and learned that the term "brake light circuit" extends to the front of the car, and not just the back. Apparently there is a common problem with the brake light switch located in the driver's footwell near the brake pedal. When the pedal is pressed, the switch is triggered and the lights come on. If the switch is broken or intermittent (my case), the lights do not come on at all. This is pretty scary since it suggests that other cars aren't seeing my brake lights come on at times.
I ordered a new brake light switch (part # 61 31 8 360 420) from Bavarian Autosport for about $12 + shipping. There are some good repair how-to's on the web. I'll be receiving the part on Monday and will try to do the repair that same day. Driving with faulty brake lights in heavy traffic can be pretty disturbing.