BMW M4 Key Fob System Dead: Locking Nightmare

Hi there! I had a similar issue with my 2019 BMW M2 Competition last year. The central locking system failed completely, no response from the key fob at all. Turned out the main door lock actuator had corroded connection pins, and there was a faulty wire harness between the control module and the door. The repair involved replacing the actuator and rewiring the connection. This wasn't a major mechanical issue, but it needed proper diagnostic equipment to pinpoint the exact problem. I initially thought it was just the key fob battery, but the onboard computer error code suggested otherwise. This kind of electrical issue needs a qualified technician with BMW-specific diagnostic tools. My technician mentioned these problems are somewhat common in this series after the 150k km mark. Make sure whoever works on it checks both the hardware and the electronic components, as just replacing parts without proper diagnosis might not solve the root cause.

Hey, thanks for sharing your experience! I actually just went through something very similar with my BMW last month. Did you remember roughly how much you ended up paying for the full repair? Also, has everything been working smoothly since they fixed it? I'm trying to get a sense of whether I should expect any follow-up issues with the locking system.

Hey again! Yeah, I can tell you exactly what I paid since I kept the invoice, it was 95 € to fix the cable and plug connection that was causing the problem. I know that's way less than I initially feared it might be! The central locking has been working perfectly since the repair, honestly like it's brand new. No problems at all in the months since they fixed it. I was pretty relieved it turned out to be just a connection issue rather than having to replace the whole actuator like I first thought. My M2 Competition has been locking and unlocking like a charm, both with the key fob and the door handle sensors. Really glad I got it sorted by a proper technician who knew what they were looking for. Don't stress too much about follow-up issues, once they fix the actual problem (rather than just guessing and replacing parts), these systems are pretty reliable. Just make sure whoever works on it does a proper diagnosis first, like they did with mine.

Just wanted to update about my experience, I took my M4 to a mechanic last week and the diagnosis was spot on! Turned out my issue was also related to faulty wiring, but in my case, it was a corroded connector in the trunk area. The repair was pretty straightforward, they cleaned up the connection points and replaced a small section of wiring. The whole thing cost me about 120 € including labor, which was such a relief because I was worried it would be way more expensive. The mechanic showed me the damaged parts, and I could clearly see where moisture had gotten in and caused the corrosion. Been testing the locks obsessively since the repair, and everything's working perfectly, all doors, trunk, everything! Really glad I didn't let my previous bad experience stop me from getting this fixed. The car feels like new again, and I'm not having to manually lock each door anymore like I was doing for the past few weeks. Thanks again for sharing your story, it really helped me understand what I might be dealing with and gave me the confidence to get it sorted!