BMW i4 Vent Odors & Failed AUC: Need Expert Input

I had a similar issue with my 2020 BMW iX3. The AUC (Automatic Recirculated Air Control) sensor went bad on mine too. When the service center checked it, they found the wiring harness connecting to the sensor was corroded and had a loose connection. It was causing erratic behavior in the ventilation system and those unpleasant smells you're describing. Got it fixed at an authorized dealer. They had to replace both the sensor and the wiring harness since there was some damage to the connector pins. It wasn't a quick fix as they needed to partially dismantle the dashboard to access the component. Though it wasn't a critical safety issue, it needed immediate attention to prevent potential damage to the ventilation system. Since the repair, my ventilation system's been working perfectly, no more strange smells or blower issues. Given your symptoms, I'd say it's worth getting a second opinion from another authorized BMW service center.

Thanks for sharing that detailed experience with your iX3! Those symptoms do sound exactly like what I'm dealing with. Can't remember if you mentioned it, how much did the whole repair set you back? Also, curious to know if you've had any other ventilation quirks pop up since they fixed it? I want to make sure I'm ready for what this might cost me and if I should expect any follow-up issues.

Hey there! Happy to give you an update about the repair costs. I just got my iX3 back from the shop, and it turned out to be a much simpler fix than my previous repair experience. They found a faulty cable connection to the AUC sensor, nothing major like I had feared. Only cost me 95€, which was a relief compared to what I was expecting! The best part? The ventilation system's working like a charm now. No funky smells, no blower issues, nothing. It's been about two weeks since the fix, and I haven't noticed any other quirks popping up. The mechanic mentioned these sensor connection problems are pretty common in newer BMWs, but once they're properly fixed, they typically stay fixed. Honestly, this repair was way less complicated than my previous experience where they had to tear into the dashboard. Looks like you might be dealing with something similar to what I just had fixed, so hopefully it'll be a straightforward repair for you too. Just make sure they thoroughly check the connections first before replacing any parts.

Thanks for all that info, really puts my mind at ease! Took your advice and got it sorted today. Funny enough, my issue was almost identical to yours. The mechanic found a loose connection in the wiring that was messing with the AUC sensor. What a relief it wasn't anything major! The repair was quick and didn't break the bank either. Best part is the ventilation's working perfectly now, no more nasty smells when I'm stuck in traffic, and the blower's back to normal. The mechanic showed me exactly what was wrong and explained everything clearly, which was a nice change from my last service experience. Definitely glad I asked here before assuming the worst. Sometimes these fancy car problems turn out to be simpler than they seem. Really appreciate you walking me through your experience, helped me avoid unnecessary stress and probably saved me some money too!