BMW Z4 Mirror Functions Dead: Heat & Auto-Dim Failure

Hey there! I had a similar issue with my 2018 BMW M2 last winter. The heated mirrors and auto-dimming completely died. Turned out the wiring harness connecting to the mirror control module was corroded, and some pins in the connector were damaged. The garage found this after running diagnostics and doing a physical inspection. It wasn't a major repair job, mostly involved replacing the connector and cleaning up the connection points. Since you're getting error codes, it's likely a similar electrical issue rather than the mirrors themselves being faulty. The technician also mentioned this is somewhat common in these models after several years of use. The fix was pretty straightforward once they identified the problem correctly. I'd recommend finding a BMW specialist who knows these electrical systems well. Get a second opinion if you're not confident with the first diagnosis, that's what I did since my first mechanic kept suggesting replacing the entire mirror units. Hope this helps with your situation.

Hey, thanks for sharing your experience! I had actually been worried it would be a much bigger issue. Did you remember roughly how much you ended up paying for the wiring harness repair? Also, just curious, has everything been working properly since the fix, or have you noticed any other electrical quirks? I'm trying to get a sense of whether I should expect any related issues to pop up after getting this sorted.

Hey again! Just wanted to update you, since my last post, I actually got this fixed at a BMW specialist. The issue was indeed similar to what I suspected, just a faulty cable connection to the mirror heating system. Total bill came to 95€, which was a relief since I was initially worried it might be something more serious. And to answer your question, everything's been working perfectly since the repair. The heated mirrors kick in right away when needed, and the auto-dimming feature is back to normal too. No other electrical issues have popped up in the last few months. It's funny how sometimes what seems like a major problem turns out to be a relatively simple fix. My M2's been running like a charm since then. The specialist mentioned these connection issues are pretty common, so at least we know it's not some unusual one-off problem. Just make sure you find someone who really knows BMWs, it makes all the difference when dealing with these electrical quirks. Worth every penny to get it done right the first time!

Thanks so much for all this info! I finally got my Z4 checked out yesterday. What a relief, it was exactly what you described, just a wiring issue. The funny part is, I was stressing about this for weeks, imagining the worst possible scenarios, and it turned out to be such a simple fix. The mechanic I found was great, really knew his stuff about BMWs. He showed me the corroded wiring and explained everything clearly. My bill was actually a bit less than yours, around 85€. Took them less than an hour to sort it out. Tested everything this morning and both the heating and auto-dimming are working perfectly again. Feel kind of silly now for putting it off for so long! Thanks again for helping me avoid a potentially expensive wild goose chase at a less specialized garage. Next time I won't let my bad experience with that last mechanic make me wait so long to get things checked out.