BMW X4 Won't Start: Dim Lights & Error Code Mystery

Hey there! I have some experience working on cars and dealt with something very similar on my 2020 BMW X3. The symptoms you're describing match exactly what happened to me, dim lights, hard start, error codes. Turned out my battery died because of a faulty alternator that wasn't charging it properly. The alternator issue was actually caused by a broken serpentine belt that wasn't detected early enough. Since it was a consequential fault from the belt issue, the workshop covered everything under warranty. They replaced both the alternator and battery at no cost. Could you share: How many miles/kilometers on your X4? Are you seeing any warning lights on the dash? Have you had any recent work done on the car? This info would help confirm if you're facing the same problem I had.

Thanks for sharing your experience! My X4 has 103859 KM on it and just had its service last month. Actually, I am seeing the battery warning light on the dash. This is really helpful info about the alternator, I was worried it might be something more serious. I'll definitely get it checked out ASAP and hopefully it's covered under warranty since the car's still pretty new. Have you had any issues since getting yours fixed?

Hey again! Glad to help out a fellow BMW owner. After getting my X3's alternator and battery replaced, I haven't had any similar issues, it's running perfectly fine now. But I'll add something I didn't mention before: I actually noticed some warning signs before the complete failure that I ignored. The radio would sometimes reset while driving, and the automatic start-stop feature became inconsistent about two weeks before things got really bad. Since you mentioned you're seeing the battery warning light and your mileage is pretty similar to what mine was when it failed (I was around 98000 KM), it really does sound like the same issue. The fact that you just had service last month is interesting though, maybe they missed something during the inspection? Quick tip from my experience: Don't wait too long to get it checked. I made that mistake and ended up stranded in a parking lot when the car finally refused to start. The warranty process was smooth, but the whole ordeal could've been less stressful if I'd acted sooner on the warning signs. Let us know what the workshop says, I'm curious to know if it's the same problem I had with mine!

Really appreciate your detailed response and the heads-up about those early warning signs! Come to think of it, I've actually noticed my radio acting weird lately too, but didn't connect the dots until you mentioned it. I've already called the workshop and booked an appointment for tomorrow morning, definitely don't want to risk getting stranded somewhere! You've been super helpful in explaining everything. The similarity between our cases is pretty striking, especially with the mileage and warning signs. I'll make sure to mention the alternator and belt possibility to the mechanic. Will post an update once I get the diagnosis, but feeling much more confident now about what I might be dealing with. Thanks again for taking the time to share your experience, it's really helped me understand what's likely going on with my X4!