BMW Climate Control Failure: Temp Sensor Mystery

Had the same issue with my 2019 BMW 3 Series last month. The symptoms matched yours exactly, climate control going haywire and temp sensor errors. Turned out it was more than just the sensor. The wiring harness connecting to the IHKA control module was damaged, and there was corrosion on the connector pins. The sensor itself was actually fine. Fixed it at the garage, they had to replace the entire wiring harness and clean the connection points. It was a bit complex since they had to remove parts of the dashboard to access everything properly. Not a quick fix, took them about 4 hours to complete the job. It was definitely worth getting it properly diagnosed rather than just replacing the sensor. Could've caused bigger problems if left unfixed, possibly even electrical issues with other components. These temperature control problems are pretty common in this series. Would suggest having a proper diagnostic done focusing on the wiring and connections before replacing any parts. Make sure they check the control module connections too.

Thanks for sharing your experience! That's really helpful since I've been worried about ending up with an expensive repair that doesn't actually fix the problem. Would you mind telling me how much you ended up paying for the whole repair? Also curious if you've had any other issues pop up since they fixed it? Really want to make sure I'm prepared for what I might be looking at cost-wise.

Hey again! Actually, I just got back from the mechanic last week and I'm happy to report my climate control is working perfectly now. Turns out my case was way simpler than I initially thought, it was just a faulty interior temperature sensor with a bad cable connection. Nothing as complex as I feared when I first replied to you. The fix was pretty straightforward and much cheaper than I expected, only paid 95 € to get the cable connection sorted out. Such a relief compared to what I was imagining! The mechanic just had to repair the connection to get everything working properly again. No other issues have popped up since the repair, the AC's running like a dream and all those annoying error messages are gone. The automatic temperature control is back to normal too. Looking back, I probably worried more than I needed to about the whole thing. Hope this helps give you a better idea of what you might be dealing with. Sometimes these things turn out to be simpler fixes than we expect!

What a relief to hear back from you! I actually took my car in yesterday after reading your earlier messages. Would you believe it, my issue was pretty similar! The mechanic found a loose connection in the wiring that was causing all the trouble. It was nowhere near as complicated as I'd built it up in my head. They fixed it in about an hour, and it only cost me around 120 bucks for the diagnostic and repair. Such a bargain compared to what I was dreading! The whole automatic climate control system is working perfectly now, no more error messages, and the AC's blowing nice and cold again. Really appreciate you taking the time to share your experience. It gave me the confidence to get it checked out instead of putting it off and potentially making things worse. Funny how we sometimes worry ourselves sick over car problems that end up having simple solutions!