BMW X5 Won't Start? Key Warning Could Be Your Answer

Had the exact same issue with my 2015 BMW X3 last month. The key warning light and no-start condition turned out to be more than just a Hall sensor problem. My diagnostic showed "Affected control unit defective" and it was actually the Digital Motor Electronics (DME) control module failing. The garage had to reprogram the DME and sync it with a new key. It was a serious electrical issue that could have left me stranded if not addressed quickly. The whole repair took about two days because they needed to order specific parts and run multiple diagnostic tests to ensure everything was communicating properly. If you're getting similar symptoms, I'd strongly suggest getting it checked at a shop that specializes in BMW electronics. The generic scan tools sometimes miss the deeper issues with these systems. While waiting for the repair, I kept a spare key handy just in case.

Thanks for sharing your experience! That's really helpful to know about the DME issue, sounds pretty similar to what I'm experiencing. I'm actually planning to take it to a BMW specialist this week. Just curious, do you remember roughly how much you ended up paying for the whole repair? Also, has everything been working smoothly since the fix? Would be great to know if any other related problems popped up afterward.

Hey there! Just wanted to follow up on your questions. After getting the car fixed, I'm happy to report everything's been running like clockwork. The repair bill came to 1000 €, not cheap, but worth every penny considering the headache it was causing. The Hall sensor in the key was definitely shot, just as I suspected, but they also sorted out that control unit issue I mentioned before. It's been about six months now, and I haven't had a single problem starting the car since. No more annoying key warning lights, no more crossing my fingers every time I turn the key! Honestly, it was such a relief to get it properly diagnosed and fixed by a specialist. They really knew their stuff with these BMW electronics. My advice? You're definitely making the right call taking it to a BMW specialist. These electronic issues can be tricky, and you want someone who knows exactly what they're looking at. Trust me, once it's fixed properly, you won't have to worry about being stranded anywhere! Let us know how it goes with your repair, always good to hear how these things turn out.

Just wanted to update everyone on my BMW situation! Finally got the car back from the shop yesterday, and what a relief! Turns out it wasn't just the Hall sensor, you were spot on about getting it checked by specialists. They found some issues with the DME module too, just like you mentioned. The bill wasn't fun, ended up being around 1200 € total, a bit more than your repair cost, but they had to replace a few extra components. But honestly? Worth every penny. The car starts up perfectly now, no more heart-stopping moments in parking lots wondering if I'll get home! Got to say, really appreciate your advice about going to the BMW specialist. The mechanic I used before clearly missed some major issues, but these guys knew exactly what they were doing. They even showed me all the faulty parts and explained everything. Thanks again for sharing your experience, it really helped me make the right decision about where to take the car. Now I can finally stop worrying every time I need to start it up!