BMW M3: ASC & ABS Failure with Acceleration Issues

Hi there! I have some experience working on cars and went through something really similar with my 2019 M4. Had the exact same symptoms: ASC/ABS warnings, jerky acceleration, the whole deal. After taking it to my regular workshop, they diagnosed a faulty ASC relay that was causing all these issues. Got it replaced for about 90 Euro and everything went back to normal. The relay basically controls the stability control systems, so when it fails, you get all those warning lights and weird behavior. Before I recommend anything specific though, could you share if you're getting any other warning lights or symptoms? Also, have you scanned for error codes? This would help confirm if we're dealing with the same issue. P.S. I've also owned an M2, but never had these problems with that one.

Thanks for sharing your experience! My M3 just had its latest service about 2 months ago at 71985 km and was running perfectly fine until these issues started popping up. I haven't scanned for codes yet, but the symptoms you described match exactly what I'm experiencing. No other warning lights besides the ASC one. The jerking during acceleration is really concerning though, especially since this car has been super smooth until now. I'll definitely get it checked out and look into that relay. Really hoping it's just that and not something more serious with the electronics. Thanks for the tip! Good to know it might be a relatively straightforward fix.

Hey again! Thanks for the additional info about your M3. Yeah, that sudden change in behavior after running smoothly is exactly what happened with my M4 too. The timing is interesting, mine also acted up a few months after a regular service, around the 65000 km mark. From what you're describing, I'm even more convinced it's the same relay issue I had. The jerking during acceleration was what worried me the most too, but it's actually a pretty common symptom when the ASC relay starts failing. Since you're not getting any other warning lights, that's another sign pointing to the relay. Just to give you a heads up, when I got mine fixed, the workshop had the part in stock and the whole repair took less than two hours. If you want to save some time, you might want to call ahead and check if they have the relay available. Keep us posted on what you find out! Always good to know if these symptoms point to the same issue across different cars. And hey, fingers crossed it's just the relay and nothing more complex!

Thanks so much for the detailed follow-up! That's really reassuring to hear that your repair was quick and straightforward. I just called my workshop and managed to schedule an appointment for next week. They actually mentioned the relay as a likely culprit too after I described the symptoms, so you might be spot on! They've got the part in stock, which is great news. The service advisor mentioned it should take about 2 hours just like in your case. I was honestly worried this might turn into some major electrical system overhaul, so hearing about your successful repair has definitely calmed my nerves a bit. I'll update the thread once it's fixed so other M3 owners can benefit from our discussion. Really appreciate you taking the time to share your experience, it's exactly the kind of firsthand info I was hoping to get!