BMW 4 Series Alarm System Dead, Silent Lock/Unlock Issue

Hi there! I had a similar issue with my 2016 BMW 3 Series diesel last year. I've got some experience working on cars, but this was definitely something I needed professional help with. The symptoms were exactly like yours, complete alarm silence and system failure. Took it to my regular workshop and they found it was just a faulty connection in the alarm siren wiring harness. The plug had corroded a bit and wasn't making proper contact. Total fix was 95 Euro, mostly labor costs for diagnosing and resolving the connection issue. Could you share what error code you're getting? Also, have you noticed any other electrical issues? This would help determine if your case is similar to what I experienced.

Thanks for sharing your experience! My car has been really reliable up until now (26381 KM, last service was just 2 months ago). Haven't noticed any other electrical issues at all. The error code I'm getting is A56F32, which points to the siren module according to the manual. Interesting that you mention the corroded connection, that sounds like it could be a similar issue, especially given the symptoms match up perfectly. Did your BMW make any unusual sounds before the alarm system completely failed? Mine made a sort of faint clicking noise for about a week before it stopped working altogether. Appreciate the help!

Hey again! Yes, actually I remember that clicking sound too! It started about 8-10 days before my system completely gave up. When you mentioned that detail, I'm now even more convinced you're dealing with the same issue I had. The error code you're getting (A56F32) is exactly what showed up on mine as well. Quick tip from my experience, when the workshop checked my car, they found that moisture had gotten into the connector over time, which led to the corrosion. The clicking was apparently the system trying to communicate with the siren but failing intermittently before it completely lost connection. Since your car has relatively low mileage and you've kept up with maintenance, I'd bet money it's the same connection problem. The repair was pretty straightforward in my case, they cleaned the connector, applied some dielectric grease, and properly sealed it. The system's been working perfectly since then. Just make sure whoever works on it checks the entire wiring harness around the siren area, sometimes there can be additional wear points that aren't immediately obvious. Better to catch any potential issues while they're in there. Let me know how it goes after you get it checked out!

Thanks again! Your detailed explanation really helps put my mind at ease. The matching error code and especially that clicking sound you mentioned, it's incredibly reassuring to know this is likely just a connection issue rather than something more serious. I've just booked my car in at the workshop for tomorrow morning, and I'll definitely mention your experience with the moisture and corrosion in the connector. It makes perfect sense about the clicking being the system trying to communicate before completely failing. I'll make sure to ask them to check the entire wiring harness while they're at it, good point about catching any other potential issues. The fact that your repair has held up well is really encouraging too. I'll update you once I get the car back from the workshop. Really appreciate you taking the time to share all these details, it's given me a much better understanding of what I'm likely dealing with. Thanks again for all your help! Best regards