BMW i3 Immobilizer Nightmare: Key System Failure Alert

I had a similar issue with my 2015 BMW i8 Hybrid last month. The immobilizer system was acting up exactly like yours, flashing warning light and engine cutting out. After taking it to the garage, they found the key fob's transponder chip wasn't communicating properly with the car's security system. The programming between the key and car's ECU had become corrupted. It turned out to be a serious issue that required reprogramming of the entire immobilizer system and recoding of both keys. The technicians mentioned this is somewhat common in BMW hybrids of our generation, especially when the key fob battery gets weak or if there's interference from other electronic devices. They had to use specialized diagnostic equipment to reset and reprogram everything. The repair wasn't quick, had to leave the car at the shop for two days while they sorted out the programming issues. But since the fix, it's been running perfectly with no more immobilizer warnings or starting problems.

Thanks for sharing your experience! That's super helpful as it sounds exactly like what I'm dealing with. Really glad to hear you got it sorted out. Would you mind letting me know roughly how much the repair ended up costing you? Also, just curious, have you had any other electrical glitches pop up since they fixed the immobilizer issue? I'm trying to figure out if I should prepare for any other potential problems down the line.

Hey there! Happy to give you an update. The immobilizer issue was completely fixed, and I'm actually really relieved it only cost me 45 € for the key reprogramming. It was just a programming glitch between the key and the car's computer, nothing more serious, thankfully! Since getting it sorted, my i8 has been running perfectly smooth with zero electrical issues. No more flashing lights, no more starting problems, it's like the problem never existed. I was also worried about potential follow-up issues, but it's been several weeks now and everything's working exactly as it should. Honestly, I got lucky with a straightforward fix. From what the tech told me, these immobilizer problems can sometimes be way more complicated and expensive. My advice would be to get it checked out sooner rather than later, catching these things early usually saves money in the long run. Just make sure you find a shop that really knows their way around BMW's hybrid systems. The right diagnostic equipment makes all the difference with these cars.

Thanks everyone! Just wanted to update you on what happened with my i3. After reading all your advice, I finally got the courage to try a different mechanic. Turns out my issue was also key-related, but a bit different. The mechanic found that moisture had gotten into the key fob and damaged some internal components. The repair was pretty straightforward, they replaced the key fob internals and reprogrammed everything. Total cost came to about 250 for parts and labor, which wasn't as bad as I'd feared. Had to hang around the shop for a couple hours while they did the work, but it was worth it. Car's running perfectly now, no more immobilizer warnings or starting issues. Really grateful for all the help and advice here. Should've dealt with this sooner instead of putting it off. At least now I know what to look out for if it ever happens again, though hopefully it won't!