BMW M4 ABS Sensor Failure: What You Need to Know

Hey there! I had a similar issue with my 2017 BMW M3 last month. The ABS warning came on, and initially, I thought it was just a sensor thing. Turned out the control unit was actually defective, not just the sensor. The mechanic found corrosion in the ABS control module, which was causing intermittent failures. They had to replace the entire ABS control unit. It was a serious repair since the ABS system is crucial for safety. The car was in the shop for three days because they needed to properly calibrate the new unit after installation. The good news is that once fixed, everything worked perfectly. My advice would be to get it checked ASAP, driving without proper ABS function isn't worth the risk. Make sure to find someone who specializes in BMW systems, as these modules need specific coding after replacement. Good luck with the repair.

Thanks for sharing your experience. It's really helpful to know what I might be dealing with. I'm curious, do you remember roughly how much you ended up paying for the whole repair? Also, has everything been running smoothly since the fix, or have you noticed any other issues pop up? I'm trying to budget for this and want to make sure I'm prepared for the worst-case scenario with my M4.

Hey again! Happy to give you an update! The total repair came to 1000 € for fixing the control unit. Trust me, I know it's not cheap, but it was worth every penny. The lateral acceleration sensor fault is completely gone now, and my M3 is running like a dream. Since the repair last month, I haven't had a single problem with the ABS system, it's working exactly as it should. No warning lights, no weird behavior, nothing. The mechanic really knew what they were doing with the BMW systems, and it shows in the quality of the repair. I'd say based on my experience, your M4 might be facing something similar. Make sure you're getting a proper diagnosis though, these systems can be tricky. And yeah, definitely set aside a decent budget just in case it is the control unit. Better to be prepared, right? Just keep in mind that prices might vary a bit depending on the specific issue, but at least this gives you a ballpark figure to work with. Hope this helps with your planning!

Just wanted to update everyone, I got my M4 fixed last week! Took your advice and found a BMW specialist. Turns out it wasn't as bad as I feared. The lateral acceleration sensor itself was faulty and needed replacement, no issues with the control unit thankfully. The mechanic was super professional and explained everything clearly. The repair took about 4 hours and cost me 400 € including parts and labor. The ABS system is working perfectly now, and all warning lights are off. The mechanic also did a quick system check and confirmed everything else is running fine. Really appreciate everyone's input, especially your detailed experience with the control unit issue. It helped me understand what I might be dealing with and prepared me for potential costs. It's such a relief to have this sorted out! Thanks again for all the help. Back to enjoying my M4 without any warning lights staring at me!