BMW 7 Series Key Symbol: Hall Sensor Malfunction Tips

Hey there! Had exactly the same issue with my 2011 BMW 5 Series. After getting stranded twice, I eventually took it to the garage. Turned out it wasn't just the Hall sensor, the whole key control unit was defective. The system wasn't recognizing the key properly, causing intermittent starting problems and that annoying key symbol on the dash. The repair involved replacing the complete control unit and reprogramming the keys. It was definitely a serious issue since the car was completely immobilized. Spent a couple of days at the garage, but it's been running perfectly since the fix. Based on your symptoms, it sounds very similar to what I experienced. Don't waste time with just the Hall sensor, get the whole control unit checked out. The high mileage on your car makes this kind of electronic failure pretty common. Hope this helps.

Thanks for sharing your experience! That does sound exactly like what I'm dealing with. Do you remember roughly how much you ended up paying for the complete control unit replacement and reprogramming? Also, has everything been working smoothly since the repair, or have you noticed any other electrical gremlins pop up?

Hey again! Glad I can update you on this! Yep, had the whole thing sorted and it cost me 1000 € for the complete control unit replacement and reprogramming work. The Hall sensor ignition key problem was definitely the culprit, just like I suspected when I first replied to you. I'm happy to report that everything's been working like a charm since the repair, no more key symbols, no more getting stranded, and not a single electrical gremlin in sight! The car starts perfectly every single time now. It's such a relief not having to worry about whether the car will start or not. Honestly, while the repair bill was pretty steep, it was totally worth it just for the peace of mind. These BMW electrical systems can be tricky, but once you get them properly sorted with the right fix, they're solid. If you're seeing the same symptoms, I'd definitely recommend just going for the full control unit replacement rather than trying partial fixes. Let me know if you need any other details about the repair, happy to help!

Thanks for all the detailed info! I bit the bullet and took my car to a different mechanic yesterday. You were spot on, it needed a full control unit replacement. My wallet's definitely feeling lighter after dropping 1200 € on the repair, but honestly, it was worth every penny. The funny part was watching the mechanic's face when he first tried to start it. The car made this weird buzzing noise, and he just gave me this knowing look like "Yep, classic BMW control unit issue." Got it back today, and it's starting up perfectly now, just like you said it would. Really appreciate everyone's help here, especially your spot-on diagnosis. Saved me from wasting time and money on just replacing the Hall sensor. Back on the road now with no more key symbols haunting my dashboard!