BMW X3 Key Fob Mystery: Lock and Start Issues Baffle Owner

Had the same problem with my 2020 BMW X4 last month. The key fob symptoms were identical, inconsistent locking/unlocking and had to use the physical key. Turned out it was a faulty antenna module connection in the front bumper area. The cable harness had some corrosion and wasn't making proper contact. The technician had to replace the antenna module and rewire the connection. It wasn't a major repair, but definitely needed professional diagnostic equipment to pinpoint the exact issue. The whole thing took about 2 hours to fix. Since then, my key fob's been working perfectly. If you're getting error codes, it's best to get it checked soon before it potentially affects other systems. Would recommend finding a shop that specializes in BMW electrical systems, they'll have the right diagnostic tools.

Thanks for sharing your experience! That's really helpful as I'm dealing with the exact same symptoms. Great to hear you got it sorted. Mind if I ask how much the repair set you back? Just trying to get a rough idea of what to expect. Also, have you had any other electrical quirks pop up since they fixed it?

Hey there! Happy to give you an update. The repair actually cost me 95€, it was mainly the cable/plug connection that was causing all the trouble. Much cheaper than I initially feared! And I've got good news, since getting it fixed, everything's been working perfectly. No more key fob issues or any other electrical problems. The mechanic really knew what they were doing with the antenna system. Honestly, it was such a relief getting it sorted. I know how annoying it is having to use the physical key all the time. Trust me, once they fix that bumper antenna connection, you'll be back to normal keyless operation. Best repair decision I've made for my X4. Like I mentioned before, just make sure you get someone who knows BMWs, it makes all the difference when they're dealing with these electrical quirks.

Thanks so much for all the detailed info! I actually went ahead and got it fixed yesterday after hearing about your experience. Found a good BMW specialist who diagnosed it right away, same issue with the antenna connection as you mentioned. Mine ended up being slightly pricier because they had to replace the whole antenna module, but totally worth it. The key fob's working perfectly now, no more fumbling with the physical key! The mechanic also cleared those error codes, and everything's back to normal. Funny thing is, I was so worried it would be something major, but it turned out to be a pretty straightforward fix. The mechanic even showed me what was wrong with the old antenna module, definitely helped me understand why it was acting up. Really appreciate you taking the time to share your experience. Saved me from stressing out too much about it and pointed me in the right direction for getting it fixed properly!