BMW i4 Mirror Heating & Auto-Dim Feature Failure Fix Needed

Hey there! I have some experience with EVs and had a similar issue with my 2022 BMW iX. My also owns an i4, so I'm quite familiar with these models. Last winter, I faced exactly the same problem with the mirror functions. Turned out the cable connecting to the mirror unit was damaged, causing both the heating and auto-dimming to fail. My local workshop diagnosed it pretty quickly, they found a faulty connection in the wiring harness. The fix cost me 95 Euro, mostly for labor and the new connector assembly. Before you head to the workshop though, could you share: Is this happening to both mirrors or just one? Did you notice any warning lights on the dash? When did you first notice the problem? This info would help compare if it's the same issue I had. These BMW electric models are great but their mirror electronics can be a bit tricky sometimes.

Thanks for the detailed response! It's actually happening on both mirrors. I've had my i4 since new, and just hit 24192 KM. No warning lights on the dash, but I started noticing this about two weeks ago when the weather got colder. At first, I thought it was just slow to respond, but now neither the heating nor auto-dimming works at all. I checked the fuse box already, but everything seems fine there. Since you mentioned the wiring harness issue, I'll definitely have that checked out. It's good to know it might not be the entire mirror unit that needs replacing. The car's been great otherwise, just this annoying little issue popping up. Did your 's i4 ever have any similar problems?

Hey, good to hear back from you! Yeah, your symptoms sound exactly like what I experienced. Interesting that it's affecting both mirrors, that was the case with mine too. When you mentioned the cold weather trigger, that really rings a bell because that's when these issues tend to show up. You know what's funny, my 's i4 actually did have a similar issue last month! But in his case, it turned out to be slightly different. The problem was a corroded ground connection near the A-pillar, which was causing intermittent issues with both mirrors. The repair was even cheaper than mine, around 70 Euro for cleaning and securing the connection properly. Since you've already checked the fuses (smart move, by the way), I'd bet money it's either the wiring harness like in my case or a ground connection like my 's car. The fact that both mirrors are affected actually makes me lean more toward the ground connection theory now that I think about it. Quick tip from my experience, when you take it to the workshop, ask them to check both the wiring harness AND the ground connections. Could save you a second trip if they just focus on one thing. These BMWs are really solid cars, but these electrical gremlins can be annoying when they pop up.

Thanks so much for all this info, you've really helped me narrow down what to look for! I'll definitely have them check both the wiring harness and ground connections when I take it in. It's reassuring to know that your had a similar issue that was fixed without breaking the bank. You're right about these electrical quirks being annoying, but I guess every car has its little issues. I've already called my regular workshop and booked it in for next week. I showed them your messages about the wiring harness and ground connection problems, and they seemed to think that's a really good starting point for the diagnosis. They estimated around 90-100 for the repair if it's similar to what you both experienced, which sounds pretty reasonable. Really appreciate you taking the time to share your experience, it's saved me a lot of worry about potentially needing whole new mirror units. I'll keep you posted on what they find!