BMW Z4 Key Fob Issues: Quick Solutions & Common Causes

Hi there! I have some experience working on BMWs, and I actually faced a similar issue with my 2004 BMW X3 last summer. The symptoms were exactly like what you're describing. My key fob stopped working, and I got warning messages too. Took it to my regular workshop, and they confirmed it was just a dead battery in the key fob. Quick fix, they replaced the battery for 37 Euro, including labor, and everything worked perfectly again. Just to rule out other potential issues, could you tell us: Have you tried using your spare key? Does the manual key blade still work for the doors? Are you having any other electrical issues?

Thanks for sharing your experience! I tried my spare key but got the same result. The manual key blade works fine for the doors, and I haven't noticed any other electrical issues. I just did my service at 61926 KM and everything else seems to be running smoothly. Kind of relieved to hear it might just be the key fob battery, definitely beats having to deal with more complex electrical problems! I'll give the battery replacement a shot and report back.

Yeah, it definitely sounds like we're dealing with the same issue here! When this happened with my X3, I also tried the spare key first and had the same problem. It's actually pretty common for both key batteries to die around the same time, especially if they're the original ones or if they were both replaced during the same service. Since you mentioned having your service done recently at 61926 KM, maybe check with your service center, they sometimes forget to mention the key battery status during routine maintenance. In my case, both key fob batteries were original and lasted about 5-6 years before giving up. Just a heads up, when I replaced my key batteries, it took a couple of tries to get the key fob to sync back up with the car. Don't panic if it doesn't work immediately after the battery change. I had to lock and unlock the doors manually a few times before the keyless system started working again. Keep us posted on how it goes after you change the batteries. I'm pretty confident this will sort out your issue, just like it did with mine.

Thanks so much for that detailed response! I actually just got back from getting both key fob batteries replaced and you were spot on about everything. Had to do that lock/unlock dance you mentioned a few times, but now both keys are working perfectly. Total cost was minimal, definitely beats what I was imagining in my head about potential electrical system failures! The service center did confirm that they typically check the key batteries during maintenance but somehow missed it during my recent service. They've now added a note to their checklist to prevent this from happening to other customers. Really appreciate everyone's help here, it's such a relief when these car issues turn out to be simple fixes. Plus, now I know what to look out for next time my key fobs start acting up. Thanks again for saving me from unnecessary worry and potentially expensive diagnostics!