BMW i8 Immobilizer Nightmare: Starting Issues & Solutions

Had the same problem with my 2016 BMW i3 Hybrid last month. The symptoms were identical, quick start then die, flashing immobilizer light. Turned out the key transponder wasn't communicating properly with the car's security system. Took it to the dealer where they diagnosed a fault in the key programming module. They had to reprogram both keys and reset the car's immobilizer system. The whole process took about half a day. It wasn't a huge mechanical issue, but definitely needed professional diagnostic equipment to sort out. My advice: this isn't something you can fix yourself, it requires dealer-level programming tools. The security system is quite complex in these hybrids. Don't waste time with regular mechanics who might not have the right diagnostic equipment. Head straight to a certified BMW dealer who can properly diagnose and reset the system.

Thanks for sharing your experience! That's really helpful as it sounds exactly like what I'm dealing with. I was worried it might be something more serious with the engine, but hearing it could be just a key/immobilizer issue is somewhat relieving. Do you remember roughly how much the dealer charged you for the reprogramming? Also, have you had any other issues with the system since they fixed it?

Hey there! Glad I could help with my previous advice about the immobilizer issue. To answer your questions, the repair was actually pretty reasonable, only cost me 45€ for the key reprogramming fix. And I'm happy to report I haven't had a single problem with the system since then. The car starts perfectly every time now, no more of that annoying flashing immobilizer light! I know I was a bit worried at first too, thinking it might be something major, but it really was just a simple programming issue in the end. The dealer's diagnostic equipment picked up the problem straight away and sorted it out. Trust me, taking it to the proper BMW service center was definitely the right call. It's worth spending a bit extra to have it done properly rather than risking issues with regular mechanics who might not have the right tools for these complex hybrid systems. Feel free to ask if you need any other info! Always happy to help another BMW owner.

Just wanted to update everyone, I took my car to the dealer yesterday following the advice here. You were absolutely right! The technician found the same issue with the key transponder not talking to the car's system properly. They plugged in their diagnostic equipment and spotted the problem right away. The whole thing took about 4 hours to fix, they reprogrammed both my keys and reset the immobilizer. Bill came to a bit more than what you paid, but honestly, I'm just relieved it wasn't something worse with the engine. Car's running perfectly now, starts up every time without any issues, and that annoying flashing light is finally gone. What a relief! Thanks again for steering me in the right direction. Definitely saved me from wasting time with mechanics who wouldn't have had the right equipment for this. Guess sometimes you really do need to bite the bullet and go to the dealer, especially with these fancy hybrid systems. Lesson learned!