BMW X1 AUC Sensor Issues: Bad Smell + Dead Blower Help

Hey there! I have some experience with car repairs and faced a similar issue with my 2007 BMW X3. The symptoms were almost identical, nasty smell and blower problems. Also had trouble with the AUC sensor. Took it to my regular workshop, and they found it was just a loose connection in the wiring harness near the sensor. They had to remove some trim panels to access it, but basically they cleaned the connections and secured everything properly. Cost me 95 Euro for the fix, including labor. Works perfectly now. Before I share more specific details about the repair, could you share: Have you noticed any warning lights? Does the smell happen only when the AC is on? Is your blower completely dead all the time or does it work intermittently? I've had my share of BMW sensor issues (also owned a 3 Series), so I might be able to help further with this info.

Thanks for sharing your experience! Last service was done just 2 months ago at 169046 KM. The blower's completely dead now, but it was working on and off for about a week before giving up. No warning lights except for the AUC sensor error code I mentioned. The smell shows up whether the AC's on or not, it's especially bad when I'm not moving. Pretty annoying during rush hour! Your X3 fix sounds promising, way cheaper than I expected. Good to know it might just be a wiring issue. Did your shop mention how common this problem is with BMWs? Just trying to figure out if I should expect more sensor troubles down the road.

Hey again! Thanks for those details about your X1. Yeah, this definitely sounds similar to what I dealt with on my X3. Actually, after reading your description, I'm even more convinced it's related to what I experienced. When my blower started that on-off behavior before dying completely, my mechanic mentioned it's a pretty common issue in these BMW models. The wiring connection problem I mentioned earlier often starts exactly like this, intermittent blower operation followed by complete failure. In my case, after they fixed the wiring, they also found some corrosion around the AUC sensor connections. They cleaned that up too, which solved both the smell and blower issues. The smell during traffic was actually happening because the system wasn't switching to recirculation mode properly. Just a heads up though, while my fix was relatively simple and cheap, these symptoms can sometimes point to a failing blower motor resistor too. My 's X1 had similar issues last year, and he ended up needing the whole resistor replaced. Still wasn't too expensive though. Based on your mileage and symptoms, I'd bet you're looking at something similar to what I had. BMW sensors can be finicky, but honestly, once fixed properly, they usually stay good for a long time. I haven't had any issues since my repair two years ago. Want me to share what specific tests my mechanic ran to diagnose it? Might help you avoid some unnecessary parts replacement.

Thanks so much for all this detailed info! It's really helpful to hear about your experience and your 's X1 too. I definitely want to know about those diagnostic tests your mechanic ran, that could save me from getting parts replaced unnecessarily. I'm feeling more optimistic now that you've explained everything. Sounds like I might be looking at a manageable repair, especially since my symptoms match what you described so closely. The fact that your fix has lasted two years is really encouraging too. I've actually just booked my car in for next week. Going to mention the wiring connection issue and the blower motor resistor to my mechanic, at least I'll sound like I know what I'm talking about! Will let you know how it turns out. Really appreciate you taking the time to share all this info!