BMW Jerking & ABS Warning: Speed Sensor Alert!

Hey there! Had the exact same issue with my 2010 BMW 3 Series 320d last winter. Started with the ABS light, then the traction control went crazy. Turns out it wasn't just a speed sensor, my ABS control unit was defective. The control unit was corroded from moisture getting in. The symptoms were identical to yours, jerky acceleration and unpredictable traction control, even on perfect roads. Think of the control unit as the brain of your ABS system, when it's failing, it sends wrong signals to your wheels. It was a serious repair since the ABS system is critical for safety. Had to get the entire control unit replaced, not just a sensor. The repair took two days because they had to program the new unit to match the car's systems. Got it fixed at an independent BMW specialist rather than the dealership. Worth getting it checked soon, you don't want to risk driving with faulty ABS and traction control.

Thanks for sharing your experience! It really helps to hear from someone who went through the same thing. Just wondering, do you remember roughly how much you ended up paying for the control unit replacement? Also, has everything been running smoothly since the repair, or have you noticed any other issues pop up?

Hey again! Glad to help with the info! Just wanted to update you, I actually got my car back from the mechanic last week after having this exact issue fixed. The total bill came to 1000 € for replacing the faulty control unit. The speed signal fault that was causing all those annoying traction issues is completely gone now. The car's running like a dream since the repair, no more jerky acceleration or ABS warnings. Honestly, it's like driving a different car! The traction control works perfectly now, even when I push it a bit. No other problems have shown up at all. Looking back, I'm really glad I got it sorted quickly. These BMW control units can cause all sorts of headaches if left unchecked. Trust me, the peace of mind is worth every cent of that repair bill. Let me know if you need any other info, happy to share more details about my experience with the repair process!

Thanks so much for the detailed follow-up! Actually, I bit the bullet and took my car to a specialist mechanic today. You were spot on, it was indeed the ABS control unit causing all the trouble. The repair set me back about 950 €, pretty close to what you paid. The mechanic I found was really thorough, took the time to explain everything, and even showed me the corroded unit they removed. Such a relief to find someone trustworthy after my previous bad experiences! They got it done in about a day and a half. Just picked up the car a few hours ago and what a difference! The jerking is completely gone, and the ABS light has finally disappeared. Feels so much safer driving it now. Guess sometimes you just have to spend the money to get things fixed properly. Really appreciate you sharing your experience, it gave me the confidence to get this sorted before it became an even bigger problem. Thanks again for all your help!