BMW X5 Won't Start, Flashing Immobilizer Light Issue

Hey there! I had a similar problem with my 2019 BMW X3 last year. I've got some experience working on cars, but immobilizer issues are pretty tricky. The symptoms were exactly like yours, car wouldn't start properly, and that annoying immobilizer light kept flashing. Turned out the key's programming was messed up. Tried the usual stuff like changing the key fob battery, but that didn't help. Took it to my regular workshop, and they reprogrammed the key. Cost me 45 Euro and fixed the issue completely. Haven't had any problems since then. Before I can give more specific advice, could you share: Have you tried using your spare key? Are there any other warning lights on the dash? Did you recently replace or repair anything related to the electrical system? That would help me understand if you're dealing with the same issue I had.

Thanks for sharing your experience! Just had my service done last month at 192,020 KM and dealing with the same frustrating issue. I've actually tried both my main and spare key, but no luck with either. No other warning lights except that pesky immobilizer one. Haven't done any electrical work recently either, it just started happening out of nowhere last week. Your key reprogramming fix sounds promising and way better than what I was imagining. Did theyage to sort it out same-day at your workshop? Really hoping it's just a programming issue like yours and not something more serious with the immobilizer system itself.

Hey again! Yeah, sounds exactly like what I dealt with. When both keys aren't working, that's usually a strong sign it's not just a key problem but might be related to the immobilizer control unit itself. But don't worry too much, in my case, they fixed it the same day. After I mentioned the key reprogramming in my last reply, I actually found out my issue was a bit more complex. The workshop discovered the immobilizer antenna ring around my ignition switch was faulty. That's why even my reprogrammed key didn't solve it completely at first. They ended up replacing the antenna ring and then reprogramming both keys. Total repair time was about 4 hours, but most of that was waiting for the parts. The actual work was pretty quick. Cost more than just the key reprogramming I initially mentioned, around 280 Euro in total, but it was worth every penny to get it sorted properly. Quick tip: keep your keys away from other electronic devices until you get this fixed. My mechanic mentioned that sometimes strong electromagnetic interference can mess with the key's signal and make the problem seem worse than it is. Let me know how it goes, I'm curious if your X5 has the same underlying issue my X3 had.

Thanks so much for all this detailed info! That's really helpful to know about the antenna ring potentially being the culprit. I've actually noticed that sometimes when I hold the key closer to the steering column, it seems to respond a bit better, which makes me think you might be onto something with the antenna issue. I'll definitely mention this to the workshop when I take it in tomorrow. I've also just realized I've been keeping my keys right next to my laptop and phone on my desk, maybe that's been making things worse like you mentioned! I'll keep them separate for now. Really appreciate you taking the time to share your experience, especially the bit about the repair time and costs. At least now I know what to expect and won't panic if they tell me it's the antenna ring. I'll update you once I get it checked out. Thanks again for all your help!