BMW M2 Key Symbol Warning, No Start Issue & Solutions

Hey there! I had a similar issue with my 2015 BMW M4 last year (some experience with basic repairs and maintenance). When my M4 showed that key symbol, I initially thought it was just the key battery, but turned out the control unit was acting up. Took it to my trusted workshop, they diagnosed it and had to replace the DME control unit. The whole thing, including diagnostics and labor, set me back about 1000 Euro. Car's been running perfectly since then. Quick question, have you checked if this happens with your spare key too? Also, could you share what error code you're getting? Might help pinpoint if it's the same issue I had with my Bimmer. If you want, I can share more specific details about the repair process and what to look out for, just need a bit more info about your situation.

Thanks for sharing your experience! Currently at 118497 KM with my last service about 2 months ago. In my case, I've tried both keys and get the same result. The error code I'm getting is 2AFC4, which seems to point toward the key recognition system. Interesting that you mention the DME control unit, my mechanic initially suspected the key itself, but given what you're saying, maybe we should look into the control unit too. Did you notice any other symptoms before your car completely failed to start? Just trying to figure out if I should prepare for a similar repair cost.

Hey again! Thanks for those details about your M2. Yeah, the situation sounds really similar to what I experienced, especially since you're getting the same issue with both keys. That's exactly what happened to me too, which is why we ended up looking beyond just the keys themselves. Before my car completely refused to start, I did notice a few weird things. Sometimes there'd be a slight delay between pressing the start button and the engine turning over, and occasionally the key symbol would flash briefly but then disappear. I just brushed it off initially (big mistake!), thinking it was just a unusual glitch. That error code you're getting is actually pretty similar to what I had. When my mechanic dug deeper into the DME issue, they found that the control unit wasn't properly communicating with the key recognition system. That's why replacing just the key wouldn't have fixed it, it was the communication system itself that was the problem. Since you're around 118K km, you're actually at a pretty similar mileage to where I was when this happened (I was at about 125K km). Based on my experience, I'd definitely recommend getting the DME checked out. Better to know what you're dealing with rather than throwing money at replacing keys that might not be the real issue. Just one thing, while you're getting it checked, might be worth having them look at the wiring connections to the DME too. In my case, there was also a slightly corroded connection that they cleaned up during the repair.

Thanks so much for all this detailed info! You've actually made me feel a bit better about the whole situation. Those symptoms you mentioned, especially the delayed start, I've definitely noticed them over the past few weeks but didn't think much of it. Really kicking myself now for not getting it checked earlier! I've just called my mechanic and mentioned what you shared about the DME unit. He agrees it's worth checking out, especially given the similar mileage and error codes. He's managed to fit me in tomorrow morning to do a thorough diagnostic of the DME system and those wiring connections you mentioned. I'll make sure to set aside around 1000 Euro just in case it turns out to be the same issue you had. Better to be prepared for the worst-case scenario! Really appreciate you taking the time to share your experience, it's helped me avoid potentially wasting money on new keys when the real problem might be something else entirely. I'll update the thread once I know what's actually wrong with it. Thanks again for your help!