BMW M2 Anti-Theft System Failure: Fix & Diagnosis Guide

Hi there! I have some experience working on BMWs. Had a similar issue with my 2016 BMW M4 (also owned an M3 before). The symptoms you're describing sound exactly like what I faced. My alarm system was completely unresponsive, and it turned out to be a simple programming issue. Took it to my trusted workshop, and they found that the alarm system needed recoding to properly activate with the optical locking signals. The fix was pretty straightforward, they reprogrammed the system, and it cost me about 45 Euro. Been working perfectly since then. Before jumping to conclusions though, could you share: Have you noticed any other electrical issues? Does your key fob work normally otherwise? Are your indicators working properly when locking/unlocking? This info would help me understand if you're dealing with the same issue I had or if it might be something different.

Thanks for your detailed response! My M2 has been pretty reliable until now (only 23111 KM on the clock since my latest service), so this issue caught me off guard. Actually, I've noticed my key fob has been acting a bit weird lately, sometimes it takes multiple clicks to lock/unlock, but the indicators still flash normally. Haven't spotted any other electrical gremlins though. Really hoping it's just a programming issue like you mentioned and not something more serious. Think I'll take it to the dealer next week. Fingers crossed it's as simple as recoding the system like in your case. Would definitely prefer that over replacing any hardware!

Hey again! Glad you got back to me, and those extra details about your M2 really help paint the picture. When you mentioned the key fob being finicky, that rings some serious bells, my M4 did exactly the same thing before the whole alarm system went kaput. Based on my experience, I'm even more convinced now that you're dealing with the same programming problem I had. Before I got mine fixed, I also noticed that intermittent key fob response you're describing. It's like the car and the key weren't speaking the same language sometimes. Just a heads up though, when I took mine in, they initially tried to convince me I needed a new control module (which would've cost a fortune). I stuck to my guns about checking the programming first, and sure enough, that's all it needed. So don't let them jump straight to replacing parts without checking the coding first. Since you're heading to the dealer, maybe ask them specifically about checking the alarm system coding and the key fob synchronization. Trust me, I've been through their diagnostic process, and sometimes they need a little nudging in the right direction. Keep me posted on what they find, would be interesting to see if it's the same gremlin I dealt with. These M cars are fantastic, but they do have their quirks with the electronics sometimes!

Thanks so much for the additional insight! It's super helpful to hear about your experience, especially the bit about them trying to push for a new control module first. I'll definitely make sure to mention the programming check when I take it in, really appreciate that tip! You've saved me from potentially spending way more than necessary. The way you described the car and key "not speaking the same language" is exactly what it feels like. It's actually a relief to hear someone else had the same issue and got it sorted without any major repairs. I'll be sure to be firm about checking the coding first before they start suggesting expensive replacements. I'll definitely let you know how it goes after the dealer visit. Fingers crossed it's just the simple fix like yours was. Really appreciate you taking the time to share your experience, car communities like this are awesome for helping each other out!