BMW X4 Battery Drama: Multiple Electrical Failures

Hey! I have some experience working on cars and dealt with something very similar on my 2019 BMW X3 last year. The symptoms were exactly like yours, dead battery, weird error messages, and all those electrical gremlins. Turned out the battery sensor was faulty, giving wrong readings to the car's computer. Had it fixed at my trusted workshop, cost me around 315 Euro including parts and labor. The mechanics said it's actually a known issue with some BMW models from that period. Before getting too deep into troubleshooting, could you share: Does the battery warning light come on? How old is your current battery? Are there any specific error codes showing up? This would help compare if it's the same problem I faced with my X3. These electrical issues can be tricky, and it's better to have all the info before heading to the shop.

Thanks for sharing your experience! I've just hit 25306 KM and had my last service about 3 months ago. Actually, yes, the battery warning light does come on occasionally, especially during cold starts. My battery is the original one that came with the car. I'm getting error code B7F334 on the dash display, along with some warnings about the electrical system. Your sensor issue definitely sounds similar to what I'm experiencing. Really helpful to know about the potential battery sensor problem, I'll make sure to mention this when I take it in. Did your mechanics have to do any other electrical checks before they found the faulty sensor?

Hey again! Yeah, your situation sounds exactly like what I went through with my X3. When I mentioned the error code to my mechanic, they immediately suspected the battery sensor, but they still ran a full diagnostic just to be safe. They actually did a complete voltage test across different points in the electrical system first. Initially, they thought it might just be the battery, but the test readings were all over the place, that's what pointed to the sensor being the culprit. The sensor was basically feeding wrong info to the car's computer, making it think the battery was dead when it wasn't. With your X4 being a 2021 model and having similar symptoms, I'd bet good money it's the same issue. Same platform, same electronics. The original battery should still be fine at that mileage, mine was too when this happened. Quick tip though, when they replace the sensor, make sure they reset the battery management system. My mechanic had to do this twice because the first time some error codes kept popping up. After the proper reset, everything's been working perfectly for the past year. Just remembered, there was also a software update they installed related to the battery management system. Might want to ask about that too when you take it in. Better to get everything sorted in one go rather than dealing with callbacks.

Thanks so much for all the detailed info! This is exactly what I needed to know before heading to the workshop. Really appreciate you mentioning the voltage test and battery management system reset, that's super helpful information I wouldn't have known to ask about. I'll definitely make sure they check for that software update too. It's such a relief to hear your car's been running perfectly after getting it fixed. The whole electrical issue has been stressing me out, but knowing there's likely a straightforward solution makes me feel much better. Will book it in for next week and make sure to mention everything you've shared. Going in armed with this knowledge will hopefully save time on diagnostics and get it sorted faster. Really grateful for your help with this!