BMW Z3 Mirror Malfunction: Heating & Dimming Issues

Hey there! I had a similar issue with my 2002 BMW Z4 last winter (I have some experience working on BMWs, mainly basic maintenance stuff). The mirror heating and dimming stopped working completely, just like yours. After struggling with it for a few days, I took it to my regular workshop. Turned out it was just a faulty wiring connection near the door panel, some cables had come loose and were barely making contact. The mechanic had to remove the door panel to access the connection point. Total bill came to 95 Euro for the fix, which wasn't too bad considering I was worried it might be the entire mirror unit. My actually had the same problem with his BMW 3 Series from around that time. These connection issues seem pretty common on BMWs from that era. Could you share more details about when this started happening? Does it happen when it's cold or all the time? Also, what's the exact error code you're getting? This would help figure out if it's the same issue I had.

Thanks for sharing your experience! Mine's at 151458 KM and just had a service done last month. The problem started happening intermittently at first, maybe like 2-3 weeks ago, but now it's constant regardless of the weather. I've been hesitant to mess with it myself since these electrical issues can be tricky. The error code I'm getting is E-458, but I was hoping to avoid a complete mirror replacement since these original parts are getting harder to find. Did your mechanic mention anything about preventing this from happening again? It's good to know it might just be a wiring issue, definitely sounds less scary than what I was imagining!

Hey again! Yeah, seeing your mileage and error code definitely rings a bell, it's super similar to what I experienced with my Z4. When my mechanic fixed those loose connections, he actually added some extra protection to the wiring harness using heat-shrink tubing and secured it better to prevent future issues. Been about 18 months now and haven't had any problems since. The E-458 code is exactly what I got too! It's funny how BMW electrical gremlins tend to follow the same patterns. My mechanic mentioned that these issues often start showing up around the 150K mark, so your timing tracks perfectly with that. One thing I didn't mention in my first reply, before getting it fixed, I tried using electrical contact cleaner on the visible connections (without taking anything apart), but that was just a temporary fix that lasted maybe a day or two. Definitely needed that proper repair job to sort it out permanently. Since you just had a service done, might be worth asking your mechanic if they noticed anything off with the door wiring during the service. Sometimes these issues start showing up after routine maintenance when things get moved around a bit. Just a thought!

Thanks so much for all the detailed info! It's super reassuring to hear that you had the exact same error code and got it fixed without needing any major parts replacement. I'll definitely get it checked out this week, sounds like it could be a relatively straightforward fix after all. Really appreciate the tip about the heat-shrink tubing too; I'll make sure to mention that to my mechanic. Actually kind of relieved it's just a common age-related issue and not something more serious. Going to give them a call right now to book it in. Thanks again for taking the time to share your experience, it's been really helpful!