BMW M4 Speedometer Error Kills Cruise Control Function

Hey there! I've got some experience with BMWs as I had a similar issue on my 2020 BMW M3. I'd consider myself to have some experience working with cars, though I'm no expert. The symptoms you're describing sound exactly like what I dealt with. My speedometer was acting weird and the cruise control just died completely. Took it to my regular workshop and it turned out to be a faulty cable connection to the speed sensor. The fix wasn't too complicated, they replaced the connection and recalibrated the system. Cost me about 95 Euro all in. Before I can give you more specific advice, could you share: How many miles/kilometers are on your M4? When did you first notice the issue? Are you getting any specific error codes? Feel free to share those details, and I'll try to help further!

Thanks for your detailed response! My M4 has 106958 KM on the clock and this issue started right after my latest service about a week ago. Currently getting error code 5892 on the system. Really hoping it's just a connection issue like you had with your M3. The timing seems suspicious since it began after the service, makes me wonder if something got knocked loose during the maintenance. Did your error appear suddenly or did it develop over time?

Hey again! Thanks for sharing those details. You know what? This sounds even more similar to my situation now. On my M3, the error also popped up suddenly, but mine happened after I had some work done on the braking system, not a regular service. The error code 5892 is exactly what I got too! Given that it started right after your service, I'm almost certain it's the same cable connection issue I had. In my case, during the work they had to remove some components near the speed sensor, and the cable didn't get properly reseated. Here's what I'd suggest, take it back to wherever did your service and explain the timing of the issue. They should check it under warranty since it started right after their work. When I mentioned this to my workshop, they actually didn't even charge me for the fix since it was their oversight. Just to put your mind at ease, once they fixed the connection and recalibrated everything, I haven't had a single problem since. The cruise control works perfectly now, and the speedometer is back to normal. It's been about 18 months since the fix. Let me know how it goes when you take it back. I'm really curious if it turns out to be the same issue!

Thanks so much for all this info, it's really helped put my mind at ease! I'll definitely take it back to the service center and mention what you've shared about the cable connection. It makes total sense that something could've been disturbed during the service. I'm honestly relieved it might be something as straightforward as this rather than a major electronic issue. I just called the service center and they've agreed to look at it tomorrow morning. They seemed pretty interested when I mentioned the error code matching your experience with the M3. Really hoping you're right about this being covered under warranty since it started right after their service. I'll update the thread once I get it sorted out, might help other M4 owners if they run into the same problem. Thanks again for taking the time to share your experience. It's exactly the kind of firsthand info I was hoping to get!