BMW iX Climate System Chaos: Multiple Sensor Failures

Hey there! I actually faced a similar problem with my 2018 BMW i4 last winter. Based on your symptoms, it sounds a lot like what I experienced, turned out to be a faulty wiring harness connector near the climate control module. When I took it to the garage, they found corroded pins in the main connector that links the climate control system to various components. The corrosion was causing intermittent communication issues with multiple systems, including the fog sensor and mirror heaters. It wasn't a major repair in terms of parts, but it required careful diagnostic work to pinpoint the exact connection point. The error codes are a good indicator that it's an electrical issue rather than mechanical. Mine was throwing similar codes before the fix. While it wasn't a serious problem that would damage the car, it definitely needed attention to prevent further issues with other connected systems. Have you noticed if the problems get worse when it's damp or particularly cold? That's usually a telltale sign of connection issues.

Thanks so much for sharing your experience, this definitely sounds like what I'm dealing with! Really helpful to know about the wiring harness connector, as I was starting to worry it might be something more serious. Just wondering, do you remember roughly how much the repair set you back? Also, has everything been running smoothly since the fix, or have you noticed any other quirks pop up?

Good to hear back from you! Happy to share that since I got the issue fixed, my i4 has been running like a dream. The mechanic found exactly what I suspected, a dodgy cable connection to the fog sensor that was causing all those weird climate control issues. I got it sorted for 95 €, pretty reasonable considering all the hassle it was causing. The fix was straightforward once they identified the problem, and honestly, it was worth every penny. Since then, no more fogged-up windows, the mirror heaters work perfectly, and those annoying error codes are gone for good. Best thing is, I haven't had a single problem with any of those systems since the repair, and that was months ago. It really was just that one faulty connection causing all the drama. If you're experiencing the same symptoms, I'd definitely recommend getting it checked out, it's likely a similar simple fix rather than anything major. Let me know how you get on with yours!

Just wanted to update you, took your advice and finally got the car checked out! Funny enough, it was exactly what you described, a corroded connector causing all that trouble. The mechanic I found was great, really knew his stuff with electric BMWs. Cost me a bit more than yours at 120 €, but honestly, such a relief to have it sorted. No more foggy windows or frozen washer nozzles, and the climate control's working perfectly now. The error codes have completely disappeared too. Actually ended up being a pretty simple fix, just like you said. Really glad I didn't put it off any longer, was starting to drive me crazy! Thanks again for pointing me in the right direction and saving me from worrying it was something more serious. All sorted now, and the car's running better than ever!