BMW 6 Diesel AUC Sensor and Blower Not Working

I had a similar issue on my '09 BMW 5 diesel (was at around 115k km). Faced the same symptoms, bad smell and blower failure. Turned out my AUC sensor wasn't just faulty, but the wiring harness connecting to it had deteriorated. The connector plugs were corroded and some wires were damaged. Last month, my mechanic found the issue during a routine check. Had to replace both the sensor and the wiring harness. It wasn't a major mechanical problem, but leaving it unfixed could've led to more electrical issues down the line. The ventilation system now works perfectly, and no more funky smells. The symptoms you're describing are pretty much identical to what I experienced. If you're worried about getting taken for a ride, ask your mechanic to show you the corroded parts. They should be visible near the sensor connection point.

Thanks a lot for sharing that! Really helpful. My symptoms do sound exactly like what you had. Hearing it was just the sensor and wiring gives me some relief, was worried it might be something more serious with the ventilation system. Mind if I ask what the repair ended up costing you? Also, have you noticed any other electrical quirks since getting it fixed? Just want to make sure I'm prepared for what might come up.

Hey again! Just wanted to update you since you asked about the costs and follow-up issues. Great news, I actually just got mine fixed, and it was way simpler than I expected. Only spent 95€ to fix the cable and plug connection. My mechanic sorted out the AUC sensor fault, and it's been working perfectly since. Haven't spotted any other electrical issues at all, everything's running smoothly. No more nasty smells, and the blower's working like new. I think we caught it early enough before it could cause any other problems. Honestly, it's such a relief having it sorted. Looking back, I was probably worrying too much about potential complications. It really was just that one connection causing all the trouble. If yours is showing the same symptoms, you'll probably be looking at a similar straightforward fix. it's such a weight off when these things turn out to be simpler than you expect, right?

Just wanted to follow up and share what happened with my car! Finally got it checked out yesterday. You guys were spot on, it was the AUC sensor and some dodgy wiring. Found a decent mechanic who actually took the time to show me the corroded parts. Cost me a bit more than yours, around 120 for parts and labor, but totally worth it. The smell's completely gone now, and the ventilation's working perfectly again. Such a relief it wasn't anything major with the engine or electronics. What really made my day was catching this before it turned into something worse. The mechanic mentioned these small issues can snowball if left unchecked. Got to admit, I was pretty nervous after my last bad experience with repairs, but this time everything went smoothly. Thanks again for sharing your experiences, really helped me know what to expect when I took it in. Sometimes it's just good to hear from others who've dealt with the same thing!