BMW 4 Series Multiple System Failures, FRS Sensor Issue?

Hey there! I had a somewhat similar experience with my 2012 BMW 3 Series. I've got some experience working on cars, but I usually leave the complex stuff to professionals. Those symptoms sound really familiar. My 3 Series had multiple electrical issues affecting the climate control and sensors. After taking it to my trusted workshop, they found a faulty wiring connection near the fog sensor that was causing all sorts of weird behavior. The repair involved replacing some corroded cables and a connector, cost me 95 Euro and fixed everything. Could you share more details about your car, like the specific engine variant and whether these issues started suddenly or developed over time? This would help me compare it better with my experience and maybe point you in the right direction. By the way, if you're getting error codes, it would be really helpful to know which ones specifically. Have you had any other electrical issues recently?

Thanks for sharing that experience! My 4 Series is at 12367 KM and just had its service last month. The issues started gradually over the past few weeks. I've got a gasoline engine model and I'm getting the P0447 and P0444 error codes now. Haven't noticed any other electrical problems so far, but it's getting pretty annoying dealing with foggy windows and no A/C. Your wiring issue situation sounds pretty similar to what I might be facing. Did you notice any warning lights on the dashboard before getting it fixed? Also, was your car acting up more during cold weather like mine is?

Hey again! Yeah, those error codes you mentioned are definitely related to the evaporative emission control system, which is different from what I initially thought. My situation does sound similar, but after hearing your specific codes, I think you might be dealing with something a bit different than what I had. In my case, I actually did have warning lights, the check engine light was flickering on and off, which was super annoying. And yes, my car was definitely more temperamental during cold weather! The heated mirrors would out of nowhere stop working, and the windows would fog up like crazy. But here's the interesting part, after they fixed the wiring, they found that moisture had actually gotten into the main control unit, which was the root cause of all those issues. Since you mentioned your car is fairly low mileage and recently serviced, I'd suggest getting it checked specifically for moisture damage in the control units. My repair ended up being pretty straightforward once they found the actual problem, but I wish I'd gotten it checked sooner. The fog and cold weather issues got way worse before I finally took it in. Have you noticed any unusual smells in the cabin? That was another symptom I forgot to mention earlier, I had a weird electrical smell right before things started going haywire with my climate control.

Thanks for the detailed response! You raise some really good points about moisture damage, and I'm glad you mentioned the electrical smell, I haven't noticed anything like that in my car yet. The warning lights situation is different too; mine hasn't shown any flickering, just steady error codes. I'm feeling more confident now that I should get this checked out ASAP before winter really kicks in. I'll definitely mention checking for moisture damage when I take it to the workshop. Based on what you're saying, it sounds like these issues can snowball pretty quickly if left unchecked. You were really helpful sharing your experience with the control unit problems. I'll make sure to ask them to inspect all the connections too, since your wiring fix seems like it could've prevented bigger issues down the line. I've already booked it in for next week, fingers crossed it's something relatively simple like your repair was!