BMW M4: Steering Shake and ABS Issues, Diagnosis Needed

Hey there! I have some experience working on cars, and this sounds very familiar. I had a similar issue with my 2016 BMW M3 last year. Initially noticed the same symptoms, shaky steering wheel, stiff turning, and those warning lights. Took it to my regular workshop, and it turned out to be a faulty tire valve causing inconsistent pressure readings. The whole thing cost me around 280 Euro to fix, including labor. After replacing the valve, all those symptoms disappeared completely. What's your current mileage? Also, have you noticed if this happens more when driving at higher speeds? Just want to make sure it's not something else, as BMWs can be tricky sometimes. I've also owned an M5, so I'm quite familiar with how these cars behave when something's not right. Let me know these details, and I might be able to help you narrow it down further before you head to the shop.

Thanks for sharing your experience! My M4 has 60744 KM on it, and I just had the service done last month. The shaking actually seems pretty consistent regardless of speed, which makes me think it might be different from what you experienced. When you mentioned the tire valve issue, did you notice any specific sounds or vibrations before getting it fixed? I'm hoping it's something simple like that, but want to gather as much info as possible before heading to the shop. The odd thing is that all these issues started happening at once, which has me a bit worried.

Hey again! Thanks for those extra details about your M4. You're right, your situation does sound a bit different from what I experienced with my M3. With my valve issue, the vibrations were definitely worse at higher speeds, and I could actually hear a slight whistling sound when driving over 70. Since your problems started simultaneously and remain consistent across different speeds, I'm now thinking it might be something else. Looking back, I probably should've mentioned that after my valve incident, I actually faced a similar set of symptoms about six months later. Turned out to be a failing power steering pump combined with a wheel speed sensor issue, which explains why both the steering got heavy and the ABS light came on at the same time. From what you're describing, I'd bet you're dealing with something similar. These M cars can be sensitive when it comes to their steering systems. Given that you just had service done last month, maybe check if anything was flagged during the inspection? The simultaneous occurrence of all these issues usually points to something more systemic than just a tire valve. Mind sharing if you've noticed any unusual noises when turning the wheel, particularly at low speeds? That could help confirm if we're looking at a power steering issue.

Thanks for the detailed follow-up! Actually, now that you mention it, I have been hearing a faint whining noise when turning at low speeds, especially in parking lots. That definitely sounds more like the power steering pump issue you described rather than just a tire valve problem. I checked my service records, and while everything looked good last month, they did note that the power steering fluid level was on the lower end of normal, guess that might've been an early warning sign I missed. Looking back, I'm glad I asked here before assuming it was just a tire issue. I'll mention the power steering pump and wheel speed sensor to my mechanic when I take it in. Hopefully catching it early will prevent any bigger problems. Really appreciate you sharing both your experiences, it's given me a much better idea of what I'm dealing with.