BMW 4 Series Multiple System Failures, Radar Sensor Issue?

Hey there! I had a similar issue with my 2015 BMW 3 series diesel. I've got some experience working on cars, though I mainly stick to basic maintenance. Last month, my BMW showed multiple warning lights and system errors. Turned out the radar sensor was just dirty, road grime and salt had built up on it. Got it professionally cleaned at my regular workshop, cost me 45 Euro, and all the warnings disappeared instantly. They told me it's quite common with BMWs. What's your exact model spec and which warning lights are you seeing? Knowing this would help determine if we're dealing with the same issue. Also, have you noticed if the warnings get worse in bad weather?

Thanks for sharing your experience! My 4 series just hit 142692 KM and had its last service two months ago. I'm getting the forward collision warning, lane departure, and adaptive cruise control warnings, plus some other unusual system messages. The weird thing is they seem to come and go out of nowhere, even in clear weather. Since you mentioned road grime being the culprit in your case, I'll definitely get that checked first before diving into more expensive repairs. The symptoms sound pretty similar to what you described. Did your mechanic mention anything specific about preventing this from happening again?

Yeah happy to help out! After my radar sensor cleaning incident with my 3 series, my mechanic actually gave me some solid advice to prevent it from happening again. When I went back for a follow-up check, they recommended regular cleaning of the front radar area, especially during winter or when driving on dirty roads. I've made it part of my routine now, whenever I wash my car, I pay extra attention to that area behind the BMW badge on the grille. Just using normal car shampoo and a soft microfiber cloth does the trick. Since that first cleaning six months ago, I've only had one minor problem when the warnings came back briefly after a long rainy period. A quick clean sorted it right out. By the way, my car's at 156,000 KM now, and keeping that sensor clean has definitely helped avoid those annoying system failures. Just a heads up though, if cleaning doesn't solve it, there might be a calibration issue. Mine needed a quick recalibration after the cleaning, which the workshop did as part of the service. Worth asking your mechanic about that too. Let me know how it goes with yours!

Thanks so much for all the detailed advice! Just got back from the workshop and you were spot on, it was mainly dirt buildup on the radar sensor. They cleaned it thoroughly and did a recalibration as you suggested. Total bill came to about 80 for both services, which is way better than I was expecting. The warnings have all cleared up now. Really appreciate the maintenance tips too. I've already marked a reminder in my phone to give that front radar area extra attention during car washes. Definitely don't want to deal with those system failures again! Can't believe such a simple solution fixed all those scary warning lights. You've saved me from what could have been an expensive repair bill. Thanks again for sharing your experience, it's been super helpful!