BMW X5 Anti-Theft System Dead, Help Needed

I faced a similar issue with my 2011 BMW X3 3.0i last month. The alarm system completely stopped responding, no lights, no chirp, nothing. Turned out the alarm control module had failed, and there was also a corroded wire in the door harness that was causing intermittent signal issues. Found a certified BMW specialist who diagnosed it properly. The repair involved replacing the alarm control module and rewiring part of the door harness. It wasn't a quick fix, took them about 4 hours to complete the work. Not the cheapest repair, but definitely needed professional expertise as these systems are quite complex. The warning signs were similar to yours, system stopped arming, no response from the key fob for locking/unlocking, and the indicators stopped flashing when locking. If you're getting error codes, it's likely the same issue. These modules commonly fail in this generation of BMWs. I'd strongly recommend finding a specialist who really knows BMW security systems. It's not something you want a general mechanic experimenting with, as incorrect coding can cause more problems.

Thanks for sharing your experience! That's really helpful and sounds exactly like what I'm dealing with. I've got the same symptoms, completely unresponsive alarm and those error codes. Good to know about the door harness issue too, hadn't thought about checking that. Do you remember roughly how much you ended up paying for the whole repair? Also, has everything been working smoothly since the fix, or have you noticed any other quirks with the system?

Hey there! Just wanted to follow up about the costs and how things worked out. After getting it fixed, everything has been working perfectly, no more alarm system drama at all! The total came to 45€, which was mainly for coding the alarm system to work properly with the optical locking signals. Those flashing indicators when you lock the car are now working like they should. Much better outcome than I expected, honestly. The specialist really knew their stuff and sorted it out way quicker than my repair took. Sometimes you just need the right mechanic for the job, you know? The whole system has been rock solid since then, proper arming, no false alarms, and the key fob works perfectly. If you're still on the fence about getting yours checked out, I'd say go for it. These BMW security systems can be tricky, but once they're properly sorted, they're actually pretty reliable. Let me know if you need any other details about how the repair went!

Thanks again for all the details! I actually bit the bullet and took it to a mechanic yesterday. You won't believe what happened, turned out to be something totally different from what I expected. The mechanic found a blown fuse and a loose connection in the trunk wiring that was causing all the drama. Got it all fixed up in about an hour and a half. The best part? It only cost me around half of what I was expecting. The mechanic was super straight with me, showed me exactly what was wrong, and even gave me some tips about preventing similar issues in the future. None of that usual confusing tech talk or unnecessary upselling. The alarm system's working perfectly now, proper arming, the lights flash when I lock it, and the remote's responding like new. Such a relief to have it sorted! Guess sometimes the simple fixes are the best ones. Really glad I didn't put this off any longer. Thanks for pushing me to get it checked out, definitely the right call!