BMW M4 Sensor Nightmare: Multiple Systems Going Dark

Hey there! I had a similar issue with my 2016 BMW M3 last year (some experience with car maintenance). Those symptoms instantly reminded me of what I went through. In my case, it was the gel pad under the windshield sensor that was forming bubbles, causing all those functions to go haywire at once. Took it to my regular workshop, and they confirmed the sensor wasn't faulty, it was just that pesky gel pad deteriorating. They replaced the pad and recalibrated the sensor. The whole thing cost me 62 Euro and worked like a charm afterward. No issues since then. Before I share more specific details about the repair process, could you share: Have you noticed any bubbles or discoloration near the sensor area? Did these issues start gradually or all at once? Are you getting any specific error codes on the display? This could help determine if you're dealing with the exact same problem I had.

Thanks for sharing your experience! My M4 has 43639 KM on it and was just serviced last month. Yeah, I've actually noticed some weird discoloration near the sensor area, and all these issues popped up pretty much overnight. Getting error code 9C4A on the display. Your gel pad theory makes a lot of sense, probably cheaper than replacing the whole sensor unit. Might give my mechanic a call and mention this specifically. Really helpful info!

Oh good to hear back from you! Yeah, that error code 9C4A is exactly what I saw on my M3 too. After seeing your mileage and hearing about the discoloration, I'm even more convinced it's the same gel pad issue I dealt with. Since you've had it serviced recently, give them a call, they should still have all your recent service records handy. Just mention the gel pad deterioration specifically. In my case, they initially thought it was the entire sensor unit too, which would've cost way more. I remember being quite relieved when it turned out to be just the pad! Quick tip from my experience, while they're replacing the pad, ask them to check the surrounding seal as well. Mine had a tiny bit of wear that they spotted during the repair, and fixing that prevented any potential water seepage issues down the line. Would love to hear how it turns out once you get it sorted. These BMWs are fantastic cars, but sometimes these small things can be a bit tricky to diagnose correctly. Keep us posted!

Thanks so much for the detailed advice! Just got off the phone with my mechanic and scheduled an appointment for tomorrow morning. Really appreciate the tip about checking the surrounding seal too, definitely going to mention that to them. It's such a relief knowing it might just be the gel pad rather than the entire sensor unit. Will definitely update once it's fixed. You've saved me potentially a lot of money and headache here! Thanks again for taking the time to share your experience, this is exactly the kind of firsthand info I was hoping to get.