BMW Z3 Key Fob Dead: Remote Entry & Start System Failed

Hey there! I had a pretty similar issue with my 1999 BMW Z4 and also own a 3 Series. I'd say I have some experience working on BMWs. When my key fob stopped working and I had starting problems, I first tried changing the battery which didn't help. Took it to my regular workshop and they found a faulty connection in the antenna wiring system. They had to replace some cables and a connector near the front bumper. The whole thing cost me 95 Euro and fixed both the remote locking and starting problems. Could you share what error code you're getting? Also, have you already tried replacing the key fob battery? These details would help me figure out if it's the same issue I had. Would also be good to know if you've noticed any other electrical issues lately.

Thanks for sharing your experience! My Z3 has 91232 KM on it and had its last service about 3 months ago. The error code I'm getting is P1629. I actually did try replacing the key fob battery already, no luck with that. Haven't noticed any other electrical issues, though the central locking sometimes makes a weird clicking sound when I use the physical key. Your repair solution sounds promising, I'll definitely have my mechanic check the antenna wiring system. Did your BMW also make any unusual sounds when using the manual key? Also, was the repair a pretty quick job, or did it take them a while to sort it out?

Hey again! Thanks for those extra details about your Z3. It's really helpful to know about the P1629 code and the clicking sound, that's exactly what mine was doing too! When I was using the manual key, mine definitely made that same weird clicking noise you described. It was super annoying, and looking back, it was definitely a sign that something wasn't right with the antenna system. As for the repair time, it was actually pretty quick once they figured out what was wrong. My mechanic had it done in about 2 hours. The trickiest part was actually testing all the connections to find the exact spot where the wiring was faulty. In my case, there was some corrosion on one of the connectors that wasn't visible until they really got in there and checked everything. Given that your symptoms are so similar to what I experienced (right down to that clicking sound), I'm even more convinced it's the same issue. The fact that you're getting the P1629 code matches up too, that's what my diagnostic showed before they found the wiring problem. Just a heads up, make sure they check all the connections thoroughly. When they first looked at mine, they almost missed a second damaged connector that would've probably caused the problem to come back if they hadn't caught it. Better to get it all sorted while they're in there! Let me know how it goes when you get it checked out. I'm curious if it turns out to be the same problem!

Thanks everyone for the helpful input! After hearing your experiences, I'm definitely going to get my mechanic to look at the antenna wiring system this week. The clicking sound being a common symptom is really reassuring, at least I know I'm not imagining things! Good tip about checking all the connections too, I'll make sure to mention that to my mechanic. It's quite a relief to know this isn't likely to be some major electrical system failure, just a faulty connection that can be fixed in a couple of hours. The repair cost sounds reasonable too, I was worried it might be something much more expensive. I'll update you all once I get it sorted. Really appreciate everyone taking the time to share their experiences and advice. Hopefully I'll be back to keyless entry and start in no time!