BMW 4 Series ABS Warning + Traction Issues Need Help

Hey! I had nearly identical symptoms on my 2014 BMW 5 Series diesel last year. The ABS light and traction control issues turned out to be quite serious, it was a faulty ABS control module, not just a sensor. When I took it to the garage, they ran diagnostics which showed "Affected control unit defective" error codes. The module was actually failing intermittently, causing those unusual jerks during acceleration you mentioned. They had to replace the entire ABS control module and recalibrate the system. The repair wasn't quick, took them about 3 days to get it sorted with the right parts. But since the fix, the car's been running perfectly smooth with no warning lights or traction issues. Don't put this repair off, faulty ABS is a serious safety concern. Get it checked at a garage that specializes in BMW diagnostics.

Thanks for sharing your experience! That's really helpful info since it sounds exactly like what I'm dealing with. The ABS control module definitely seems like it could be the culprit. Mind if I ask how much the whole repair ended up costing you? Also curious if you've had any other issues pop up since getting it fixed?

Hey again! Happy to help with more details. Just thought I'd update you, I actually visited my mechanic last month and got everything sorted out. The Speed signal fault that was causing all those problems has been completely fixed. The repair bill came to 1000 € for replacing the faulty control unit, but honestly, it was worth every cent. Since getting it fixed, my 5 Series has been running like a dream, no more warning lights, no jerking during acceleration, and the traction control works perfectly now. Haven't had a single issue pop up in the last month. The car feels way more stable and safe to drive, especially when I need to brake suddenly. I know the cost might seem steep, but considering it's a safety-critical system, I wouldn't recommend trying to save money with temporary fixes. The peace of mind alone is worth it. Plus, the new control unit should last for years to come. Hope this helps with your decision!

Thank you so much for all this information! I actually just got back from the mechanic today, and you wouldn't believe it, my situation was quite different from what we thought. Turns out it was a combination of a damaged wheel bearing and a loose connection in the wiring harness. The whole repair took just about a day and cost me around 600 bucks, which was way less than I was expecting after hearing about your ABS module replacement. The mechanic showed me the old bearing, it was completely shot! No wonder my car was acting up. They also cleaned and secured all the connections properly. Just drove it home and it feels like a completely different car, super smooth, no warning lights, and the traction control is working perfectly now. Really glad I didn't put this off any longer. Thanks again for pushing me to get it checked out properly!