BMW Z3 Electronic Brake Failure, Common Causes & Solutions

Hey there! I have some experience working on BMWs. Had a similar issue with my 2000 BMW Z4, and my owns a 3-series from that era. The symptoms you're describing sound exactly like what I dealt with. My electronic parking brake failed completely, and those warning lights drove me crazy! Turned out the electric motor in the brake caliper was toast. Took it to my regular workshop, and they diagnosed it pretty quickly. Had to replace the entire brake caliper assembly with the motor. The whole thing set me back about 505 Euro, but it's been working perfectly since then. Could you share some more details about your Z3? Like when did this start happening, and are you hearing any unusual sounds when engaging the parking brake? This would help me give you more specific advice based on my experience. One thing though, get it checked soon. These brake issues aren't something you want to leave unattended.

Thanks for the detailed reply! My Z3 has 168013 KM on it and was just serviced last month. The parking brake actually started acting up right after the service, no grinding or weird noises, it just stopped engaging altogether. Really appreciate you sharing your experience with the caliper motor. That's actually super helpful since I was worried it might be something more serious with the entire brake system. I'll definitely get it checked out asap. Did you notice any difference in performance after the caliper replacement, like smoother engagement or quicker response?

Hey again! Thanks for the follow-up. Interesting that the issue started right after your service, that's actually different from what happened with my Z4. Yeah, after I got the new caliper assembly installed, there was definitely a noticeable improvement. The engagement became way smoother and more precise compared to how it was before it failed. You know that slight delay we used to get with these older electronic parking brakes? That completely disappeared with the new unit. Since you mentioned it started after the service, you might want to ask them to check if something got disconnected or damaged during the maintenance work. In my case, the motor just died from age and use, but yours sounds a bit suspicious with the timing. By the way, the repair took about 2-3 hours in my case. Make sure whoever works on it has experience with BMW electronic parking brake systems, they can be a bit tricky. When they fixed mine, they also had to recalibrate the system using proper diagnostic equipment. Keep us posted on what you find out! Always good to share these experiences for other Z3/Z4 owners who might run into similar issues.

Thanks so much for all this information! That's really reassuring to hear about the performance improvements after your repair. I'll definitely bring up the timing with my service center since it does seem pretty suspicious that it happened right after maintenance. I actually called them earlier today and scheduled an appointment for next week. They confirmed they have the BMW diagnostic equipment, so hopefully they can handle the calibration part too. The 2-3 hour repair time helps me plan better, I was worried it might be a multiple-day job. I'll make sure to ask specifically about the caliper motor when I take it in. Really appreciate you sharing your experience, especially about making sure they have BMW-specific knowledge. I'll update this thread once I get it sorted out so others can benefit from my experience too. Thanks again for all your help!