BMW Z3 Climate Control Failure Troubleshooting Help

Hey there! I had a similar issue with my 2004 BMW Z4 last summer. The symptoms were almost identical, climate control going crazy and AC not responding. Turned out the temperature sensor connector was corroded and had a loose connection. The mechanic also found that some wiring insulation near the sensor was damaged. In my case, it wasn't as serious as I initially feared. The fix involved cleaning the connector, repairing the wiring, and securing the connection properly. The whole repair took about 2 hours. Just had to replace the sensor connector and rewire that section. Based on your description, it sounds very similar to what I experienced. It's not typically a major repair, but you'll want a mechanic who's familiar with BMW electrical systems to handle it. The symptoms can sometimes point to the control module too, but start with checking those connections first. Hope this helps with your decision.

Hey, thanks so much for sharing your experience! This sounds exactly like what I'm dealing with. I'm feeling a bit more optimistic now knowing it might just be a connection/wiring issue rather than something major. Do you remember roughly what you paid for the repair? Just trying to get a ballpark figure so I know what to expect. Also, has everything been working fine since the fix, or have you had any other climate control problems?

Hey again! Great news, I can actually help with some fresh info! Just saw my mechanic about this last week, and yep, it was exactly what we thought, a faulty interior temp sensor. The fix was pretty straightforward, just needed to sort out a dodgy cable connection to the sensor. Only set me back 95€, which was a relief since I was worried it might be something way more expensive. And to answer your other question, everything's been working like a charm since then! The climate control is back to normal, AC's responding perfectly, and those annoying error messages are gone. Seriously, it's like having a new car climate system. My Z4's been running super smooth, and I haven't had a single problem with the temperature controls since. Pretty relieved it turned out to be such a simple fix. Sounds like you're dealing with the exact same thing I was. Hope this gives you a better idea of what you're looking at cost-wise!

Thanks for all that detailed info! I actually went ahead and got it checked out yesterday at a BMW specialist. You were spot on about it being a relatively simple fix. The mechanic found a corroded sensor connection, just like in your case. Had to pay a bit more than you did, around 150 for parts and labor, but honestly, I'm just relieved it wasn't something major. The whole thing only took about an hour and a half. The mechanic showed me the old corroded parts and explained everything, which I really appreciated after my last bad repair experience. The best part? The AC's working perfectly now and those error messages are gone. The auto climate control is responding just like it should. Such a weight off my mind! Really grateful for your help in pointing me in the right direction. Sometimes these older BMWs can be tricky, but it's nice when the fix turns out to be straightforward. Thanks again for sharing your experience, it really helped me avoid getting overcharged for what turned out to be a pretty simple repair!