BMW X6 Climate Control Failure, AUC Sensor Issues?

Hey there! I had something very similar with my 2017 BMW X4, so I know how annoying these climate control issues can be. I've got some experience working on cars, but nothing too advanced. My blower also died completely, and I was getting those nasty exhaust fumes in traffic. Took it to my regular workshop, and it turned out to be a loose connection in the AUC sensor wiring harness. They found some corroded plug pins that were causing poor contact. The fix was pretty straightforward, they cleaned the connections and replaced one damaged cable. Cost me around 95 Euro and works perfectly now. Before I can give you more specific advice, could you share: Have you noticed any warning lights? Did this start suddenly or get worse over time? Does your blower work at all or is it completely dead? Those details would help me share more relevant info from my experience.

Thanks for your detailed response! My X6 is pretty well maintained (last service was at 150537 KM), and yeah, this started gradually over the past couple weeks. No warning lights on the dash, but the blower's totally dead now, won't respond at any speed setting. Actually, what you mentioned about the corroded plug pins sounds pretty close to what I'm experiencing. It's good to know it might not be something super major. Was your repair done under warranty, or did you have to cover it yourself? My extended warranty is about to expire, so I'm thinking I should get this checked out soon.

Hey again! Glad I could help earlier. Yeah, based on what you're describing, it sounds even more similar to what I experienced with my X4. Mine wasn't under warranty anymore when this happened, so I had to pay out of pocket. Honestly, given that your extended warranty is almost up, I'd definitely get it checked ASAP, might save you some cash! Just a heads up though, while my issue was the corroded pins, there could be other things causing similar symptoms. When my mechanic dug deeper, they actually found some moisture had gotten into the connection points over time, which led to the corrosion. They mentioned it's pretty common in these models as the wiring harness is exposed to various weather conditions. The good news is, if it is the same issue, it's not a huge repair job. My car's been running perfectly for about 8 months since the fix. Just one piece of advice, make sure whoever looks at it is familiar with BMW electrical systems. The first shop I went to missed the connection issue completely and wanted to replace the entire AUC sensor unit, which would've cost way more. Let me know what you find out when you get it checked. Curious to see if it's the same problem!

Thanks so much for all that insight! Really appreciate you sharing your experience in such detail. You've definitely convinced me to get this checked out while my warranty's still valid, booking an appointment first thing tomorrow. I've actually got a BMW-certified shop nearby that I trust, so hopefully they'll be able to spot if it's just those corroded connections rather than jumping straight to replacing the whole unit. It's super helpful knowing about that possible misdiagnosis you mentioned. Good to hear your repair has held up for 8 months now. Fingers crossed mine turns out to be something similarly straightforward! I'll update the forum once I get it sorted out, might help someone else dealing with the same issue down the line. Thanks again for taking the time to share all this, really helped put my mind at ease about the whole situation.