BMW M3 E-Brake Nightmare: Multiple System Failures

Hi there! I can relate, had a similar issue with my 2012 BMW M5 last year. I have some experience working on cars, but electrical issues are definitely not my forte. The symptoms you're describing sound exactly like what I dealt with. My brake caliper's electric motor was shot, triggering multiple system warnings since everything's interconnected on these cars. Took it to my trusted workshop, they diagnosed it pretty quickly. Had to replace the electric motor in the brake caliper and recalibrate the system. Cost me around 505 Euro, but it fixed all the warnings and the parking brake works perfectly now. Before I can share more specific details, could you share: How many miles/kilometers on your M3? Are you hearing any unusual sounds when engaging the parking brake? Did these issues start suddenly or gradually? These details would help me give you more targeted advice based on my experience with the M5.

Thanks for asking! My M3 has 39564 KM on the clock, and yes, I'm hearing a grinding noise when trying to engage the parking brake. The issue started quite suddenly after my latest service. The dealership didn't mention anything unusual during the checkup, which is strange. Your experience with the M5 sounds very similar to what I'm dealing with. Were there any warning signs before your caliper motor completely failed? Just trying to understand if I should expect more issues popping up.

Hey again! Yes, that grinding noise is exactly what I experienced with my M5 before the caliper motor completely died. Since you mentioned it started after the service, that's actually quite interesting, mine also began acting up after routine maintenance. Makes me wonder if there's a connection there. In my case, there weren't really any warning signs before the grinding noise started. Once I heard that sound though, things went downhill pretty fast. Within about a week, all those warning lights you mentioned started popping up on my dash too. Looking at your mileage (39564 KM), that's actually pretty similar to when mine failed (around 42000 KM). It's kind of a common failure point from what I've learned since my repair. The grinding noise is definitely a red flag, that's the electric motor struggling to engage properly. Quick word of advice based on my experience: don't wait too long to get it fixed. I tried to "live with it" for a couple of weeks and ended up causing more wear on the caliper itself. Ended up having to replace both the motor and caliper, which made the repair more expensive than necessary. Have you noticed if the issue is worse when the car's been sitting for a while? That was another thing I experienced, it seemed to act up more after the car had been parked overnight.

Thanks so much for all that detailed info! Yeah, mine's definitely worse in the morning after sitting overnight, exactly like you described. You've really got me worried now about causing additional damage. I was planning to wait until next month to get it looked at, but after hearing about your experience, I think I'll book it in this week. Don't want to risk needing a full caliper replacement on top of everything else. Can't believe how similar our situations are, same mileage range, issues starting after service, and those identical symptoms. Really appreciate you sharing your experience. I'll make sure to mention the caliper motor to my mechanic when I take it in. The grinding noise has actually gotten a bit worse just in the past few days, so you're probably right about things going downhill fast. Better to fix it now than deal with a bigger headache later. Thanks again for helping me avoid a potentially more expensive repair!