BMW M4: ASC & ABS Failure + Acceleration Problems

Hey there! I have some experience working on cars, and I actually dealt with a similar issue on my 2021 BMW M3 last year. These symptoms sound very familiar, I had the same warnings and that nasty jerking sensation during acceleration. Turned out it was a defective ASC relay in my case. Got it fixed at my trusted workshop for about 90 Euro, parts and labor included. The mechanics diagnosed it pretty quickly since it's apparently a known issue with some BMWs. My mechanic also mentioned seeing this on several M2s. Before suggesting anything specific though, could you share: Any other warning lights? Does it happen only during warm-up or all the time? Have you scanned for error codes? Let me know these details and I might be able to help you narrow it down further based on my experience.

Thanks for your detailed response! Yeah, I've had my M4 since new and just hit 166372 KM. The jerking happens all the time, not just during warm-up. Got three warning lights now, ASC, ABS, and the service indicator. Haven't scanned it yet cause I wanted to check with fellow BMW owners first before taking it in. Really interesting about that ASC relay issue you mentioned. Was hoping it would be something simple like that rather than a major problem. Had my last service about two months ago and everything was perfect then. Maybe I'll get those error codes checked first and report back.

Hey again! Thanks for the additional info about your M4. Yeah, those symptoms are pretty much identical to what I experienced. Given the mileage on your car and the combination of warning lights, I'm still leaning towards the ASC relay being the culprit, especially since it started happening suddenly after everything was fine at your last service. When my M3 had this issue, the three warning lights came on together just like yours. The jerking during acceleration was really annoying, right? Made me nervous to drive it at first. I actually drove it like that for about a week before getting it fixed (probably not the smartest move, but you know how it goes). Definitely get those error codes read, that'll confirm if it's the same issue. My codes pointed to a communication error between the ASC module and the car's computer system, which led straight to that faulty relay. If you want, let me know what codes you get and I can tell you if they match what I saw with mine. Just be careful driving it until you get it sorted, these systems are pretty important for handling and safety, as I'm sure you know! Just curious, have you noticed any other electrical quirks? My radio was acting up a bit too when this happened, though that might've been unrelated.

Thanks for sharing your experience! You're dead on about how annoying that jerking is, makes me nervous every time I need to accelerate. I'll definitely get those codes read first thing tomorrow. The radio's actually been fine, but now that you mention electrical issues, my power windows have been a bit sluggish lately. Didn't think they might be connected, but maybe there's something to that. Really hoping it's just that ASC relay like in your case. The symptoms matching up exactly gives me some hope it'll be a straightforward fix. After spending so much on maintenance recently, the last thing I need is a major repair bill! I'll probably avoid driving it too much until I get this sorted, don't want to risk making anything worse. Thanks again for all the detailed info about your experience. I'll definitely update once I get those error codes and find out what's actually going on with my M4. These kinds of issues can be so frustrating, but it really helps knowing others have dealt with similar problems and got them fixed without too much drama.