BMW X4 Convertible Top Failure: Hall Sensor Mystery

Hey there! I had a somewhat similar issue with my 2019 BMW X6 (switched from an X3 before). I have some experience working on cars, but electrical issues aren't my forte. The symptoms you're describing sound very familiar. My convertible top was acting up the same way, warning lights, unusual stops, the whole deal. Turned out it was a loose connection in the wiring harness that controls the top mechanism. My mechanic found that some cables had worked themselves loose over time. The fix was pretty straightforward, they had to reconnect and secure the cables properly, then reset the system. Cost me about 95 Euro and hasn't given me any trouble since. Before I can help more specifically, could you tell me if you've noticed any patterns when the problem occurs? Like does it happen more often when it's cold or after the car sits for a while? Also, what error code exactly did you get from the scan? This would help narrow down if we're dealing with the same issue.

Hey, thanks for sharing your experience! My X4 has 184275 KM on the clock and I've kept up with all scheduled maintenance. The issue seems most noticeable during cold mornings, which makes me think your wiring harness theory could be spot on. I'm a bit hesitant to try fixing it myself though, even with some DIY experience. The error code I got was B376542, and the warning light behavior seems pretty similar to what you described. Did your mechanic mention any other potential causes they ruled out before finding the loose connection? Just want to make sure I'm prepared when I take it in. Have you had any problems since the repair? Would be great to know if it's held up well over time.

Hey again! Thanks for those details about your X4. Yeah, when you mention the cold morning issues, it definitely sounds similar to what I experienced. Since you asked, after my initial repair, I've had zero problems for about 18 months now. The top works perfectly, no warning lights, nothing. When my mechanic worked on it, they actually first suspected the hall sensor like you mentioned (given the error code), but after a thorough inspection, they found those loose connections I told you about. They also checked the hydraulic system and the microswitches, just to be thorough. The wiring issue was causing similar symptoms because the system wasn't getting consistent signals. Given your mileage (mine was around 165000 KM when this happened), these kinds of issues aren't uncommon. The constant opening and closing of the top can stress the wiring over time. While DIY is great for some things, I'd definitely recommend having a professional look at it, especially since it's an electrical issue. These systems are pretty complex, and one wrong move could make things worse. One tip though, when you take it in, make sure they check the entire wiring harness, not just the obvious spots. Sometimes these issues can be tricky to pinpoint. Keep us posted on what they find!

Thanks so much for all that detailed information! You've definitely put my mind at ease about this whole situation. It's really helpful to hear that your repair has held up well for 18 months, that's exactly the kind of long-term reliability I'm hoping for. Totally agree about leaving this to the professionals. I've already called my regular BMW mechanic and scheduled an appointment for next week. I made sure to mention everything we discussed about the wiring harness and the cold weather correlation. They seemed pretty confident they could sort it out, especially with the error code information. I'll definitely give an update once it's fixed. Really appreciate you taking the time to share your experience, it's going to make my conversation with the mechanic much more informed. This community is always so helpful with these kinds of issues!