BMW 5 Hybrid Climate System Chaos: Fog Sensor Alert

Hey there! I actually faced nearly identical issues with my 2020 BMW 3 Series Hybrid last winter. The symptoms you're describing sound exactly like what I experienced, it turned out to be more than just a fog sensor issue in my case. After a thorough diagnostic at the garage, they found that the main control module for the climate system had a damaged cable connection. The connection had corroded over time, causing intermittent failures across multiple systems. They had to replace the entire wiring harness connected to the climate control module. It was definitely a serious issue since it affected multiple systems and could've led to more problems if left unchecked. The repair involved removing several dashboard components to access the wiring, plus programming the new module to sync with the car's systems. Quick tip: Make sure they check the grounds and connections near the firewall too, mine had some moisture damage there that contributed to the problem.

Thanks for sharing your experience! That wiring harness issue sounds exactly like what might be happening with mine too. The symptoms match perfectly. Just curious, do you remember roughly what the repair bill came to? Also, has everything been working smoothly since they fixed it, or have you noticed any other quirks popping up?

Hey again! Just wanted to let you know my fog sensor issue got sorted out, what a relief! Took it to the mechanic and it turned out to be way simpler (and cheaper!) than my initial repair. They found a dodgy cable connection that was causing all the trouble. Just needed to fix that connection and boom, everything's working perfectly now. Only cost me 95 € for the repair, which was a nice surprise compared to what I was expecting after my previous wiring harness drama. All the systems are working like a charm now, climate control, mirror heaters, the lot. No more foggy windows or weird AC issues. Been about three months since the fix and haven't had a single problem. Everything's stayed super stable, which is exactly what you want to hear, right? Much better outcome than my previous repair saga that I mentioned before!

What a relief to hear back about this! After reading your update, I went ahead and took my car to a new mechanic yesterday. You wouldn't believe it, turns out I had almost the exact same problem! Just a faulty connection causing all that drama. The repair was pretty quick, took them about two hours to fix it. The bill came to around 120 bucks, which isn't too bad considering I was bracing myself for much worse after your first wiring harness story. They also did a quick check of the other connections while they were at it, so that's good peace of mind. Just drove home from work today and everything's working perfectly, no fogged windows, AC's running great, and even those pesky washer nozzles are behaving themselves. Really glad I asked for advice here instead of just rushing to get the whole system replaced. Thanks again for sharing your experience, definitely helped me avoid potentially unnecessary repairs!