BMW M2 Mirror Heating & Auto-Dim Failure: Fix Guide

Hey there! I faced a similar issue with my 2018 BMW M4 last winter. The mirror functions died completely, both heating and dimming. Turned out to be a failed wiring harness connection where the cables run through the door hinge area. The constant opening and closing had worn down the protective sleeve, causing a short. After dealing with three different garages, finally found someone who knew what they were looking at. They had to replace the entire door wiring harness and check all the connections to the mirror assembly. Not a huge repair in terms of parts, but it needed precise diagnostic work to pinpoint the exact failure point. Before the fix, I was getting the same error codes you're seeing. The symptoms match exactly what you're describing. While not a critical safety issue, it's definitely something you want sorted before winter hits. Just make sure whoever works on it has experience with BMW electronics, saved me a lot of headache in the end. My two cents: Get it checked soon, as moisture can make the problem worse over time.

Thanks for sharing your experience! This actually sounds exactly like what I'm dealing with. Your suggestion about getting it checked soon makes a lot of sense, especially since I've noticed some moisture building up recently. Do you remember roughly how much you ended up paying for the harness replacement and labor? Also, has everything been working properly since the repair, or have you noticed any other electrical quirks?

Hey again! Great news, I actually got my issue fixed last week! Turned out to be much simpler (and cheaper!) than my initial repair. It wasn't the entire wiring harness after all, just a loose cable connection to the mirror heating element. The mechanic found a damaged plug that was causing the problem. Total cost came to 95 € which was a huge relief compared to what I was expecting. The repair only took about an hour, and both the heating and auto-dimming are working perfectly now. No more moisture issues either. Since you're seeing similar symptoms, it might be worth checking the connections first before jumping to a full harness replacement like I originally had done. My mechanic mentioned these plug issues are actually pretty common on our BMWs. Everything's been working flawlessly since the fix, no electrical gremlins or other quirks to report. Just nice, clear, fog-free mirrors! Definitely worth getting it sorted sooner rather than later. Good luck with yours!

What a relief to hear about your recent fix! I actually went ahead and got mine checked out yesterday at a new mechanic. You won't believe it, but it was almost the exact same issue, just a faulty connection and a broken plug. The mechanic showed me the damaged part and explained everything really clearly. Total bill came to around 120 bucks, which feels like a steal compared to what I was worrying about! They got it done in about an hour and a half. Both mirror functions are working perfectly now, tested the heating this morning and it's like new. Really glad I asked here before going back to my old mechanic. They probably would've tried replacing the entire harness without even checking the simple stuff first. Thanks again for sharing your experience, saved me a bunch of time and money! Sometimes the simplest solution really is the right one. Time to enjoy those properly working mirrors and stop worrying about moisture build-up!