M2 Key Fob Failures: Electronic Door Handle Troubles?

Hey there! I've got some experience with BMWs, I have a 2018 M4 and I had a very similar issue last year. I'm somewhat experienced with car maintenance, but electrical problems can be tricky. My keyless entry stopped working too, and the error messages were pretty much identical. After struggling with it for a few days, I took it to my trusted workshop. Turned out the wiring connection to the door handle sensor was damaged, causing intermittent failures. The mechanic found a loose plug connection that had some corrosion buildup. They replaced the cable and cleaned the connector points. Cost me about 95 Euro and it's been working perfectly since then. Pretty straightforward fix once they identified the problem. What's your current mileage and have you noticed any other electrical issues? Also, did this start suddenly or was it getting progressively worse? This info would help me figure out if you're dealing with the exact same problem I had.

Thanks for sharing your experience! My M2 has done 107136 KM and this issue popped up right after my last service two weeks ago. It's interesting you mention the wiring connection, I've noticed the problem seems worse when it rains, which could point to that corrosion issue you mentioned. Haven't spotted any other electrical gremlins yet, but it's definitely been a sudden thing rather than gradual. I'll get it checked out at the workshop and have them look specifically at those connector points. Rather have it fixed properly than keep dealing with this hassle.

Yeah that definitely sounds similar to what I experienced, especially the rain connection! After you mentioned it happened after the service, it got me thinking, when they worked on my M4, they might have accidentally disturbed the wiring during the service. These things are pretty sensitive. In my case, after they fixed the corroded connector, they also applied some dielectric grease to protect it from moisture. That's probably why I haven't had any issues since, even in wet weather. One thing I forgot to mention in my first reply, before taking it to the workshop, I tried cleaning the key fob contacts and replacing its battery, thinking that might be the issue. Didn't help at all, so I wouldn't waste your time with that. The connector problem seems to be a common weak point in these models. Given that your issue started right after the service, you might want to mention that when you take it in. They might even cover it under warranty if they accidentally caused the problem during maintenance. Keep us posted on what they find, always good to know for future reference!

Thanks for the follow-up info! That's really helpful to know about the dielectric grease, I'll definitely ask them to include that when they fix it. You're right about the service timing being suspicious. I just called the workshop and mentioned how it started right after their work, and they've agreed to take a look at it under warranty. Pretty decent of them, honestly. Funny you mention trying the key fob battery first, I actually did the same thing! Went through the whole process of cleaning contacts and replacing the battery before realizing it had to be something bigger. At least now I have a fresh battery in there, so not a complete waste of time. Really appreciate you sharing your experience with this. It's given me a much clearer idea of what to expect when I take it in. I'll update the thread once it's fixed in case anyone else runs into the same problem later on.