BMW i8 Key Symbol Error: Fix for Dead Engine Issue

Hey there! I've got some experience with BMW hybrids as I dealt with a similar issue on my 2016 BMW i3. Really frustrating when these electronic gremlins pop up! Had exactly the same symptoms, key symbol, no start, error codes. Took it to my regular workshop and they diagnosed a defective control unit. The repair cost me around 1000 Euro, but it sorted out the problem completely. Been running smoothly since then. Before going further, could you share: Have you tried using your spare key? Are there any other warning lights? Did you get the specific error code read? This info would help determine if you're facing the same issue I had. I know BMW tech pretty well (been working on them for a few years), so happy to give more specific advice once you share these details.

Thanks for your detailed response! Yes, I've already tried both keys and got the same result. The error code is P0615, and besides the key symbol, there's also a battery warning light. Last service was done 3 months ago at 127329 KM. Mine is behaving a bit differently from what you described though. Sometimes it starts after multiple attempts, but mostly just shows that annoying key symbol. Good to know about the control unit, I'll definitely keep that in mind when I take it to the workshop. Did your repair include any software updates? Just wondering if that might be part of the solution since these hybrids can be pretty complex with all their electronics.

Hey again! Thanks for the additional info. Yeah, seeing those symptoms and especially that P0615 code actually makes me think your issue might be different from what I initially experienced with my i3. That error code typically points to the starter relay circuit, and with the battery warning light also showing up, I'm leaning towards an electrical system issue rather than the control unit problem I had. In my case, there weren't any battery warnings at all. And to answer your question about software updates, yes, my repair did include a software update, but it was more of a routine thing rather than part of the actual fix. These hybrid systems are super sophisticated, so the workshops usually do updates whenever they get the chance. Here's what's interesting though, since you mentioned it sometimes starts after multiple attempts, that's actually a pretty important clue. In my experience with BMW hybrids, when it's a pure key/immobilizer issue, it usually won't start at all. The intermittent starting suggests it might be more of a power supply or relay problem. Have you noticed any other electrical quirks lately? Like flickering lights or slow power windows? Just trying to help narrow it down before you spend big money at the workshop like I did!

Thanks so much for breaking that down! You've given me a much clearer picture of what might be going on. Actually, now that you mention electrical quirks, I have noticed my power windows being a bit sluggish lately, and the interior lights sometimes flicker when I'm trying to start the car. I totally dismissed these as minor annoyances, but they're probably connected to the bigger issue. You're absolutely right, this does sound more like an electrical system problem rather than what you experienced with your i3. It's actually a relief in a way, because dealing with a faulty relay should be less expensive than replacing an entire control unit. I'll make sure to mention these symptoms when I take it to the workshop tomorrow. Really appreciate you taking the time to share your experience and help me diagnose this. Even though it turned out to be a different issue, your insights helped me understand what to look for and what to tell the mechanics. I'll update you once I get it sorted!