BMW X3 Alarm System Dead: Backup Battery Suspect?

I had a similar issue with my 2018 BMW X5 last year. The alarm system failed completely, and the diagnostic showed it was indeed the backup battery. These backup batteries typically last 3-4 years, and when they die, the alarm system stops functioning. Got it fixed at the garage and it was a straightforward repair, basically just needed a new backup battery unit and a system reset. It wasn't a serious issue, but definitely something that needed immediate attention for security reasons. The mechanic also checked the main battery's health while at it, which was good practice since these systems are connected. The whole thing took about an hour to fix. Been working perfectly since then with no recurring issues. If you're getting an error code, it's pretty likely you're dealing with the same problem. Make sure whoever works on it uses genuine BMW parts for the replacement.

Hey, same thing happened to my X3! Your situation sounds exactly like what I dealt with. My backup battery also died and caused the alarm to stop working completely. I got it sorted at a repair shop and it's been working fine since then. Just curious, do you remember how much you ended up paying for the fix? And has everything been working properly since the repair? Just want to make sure I wasn't overcharged compared to others, and it'd be good to know if you've had any other alarm-related problems pop up afterward.

Hey there! Glad to hear you got it fixed too! After my last post, I actually took my X5 to the mechanic because I got the "Additional battery alarm system defective" warning. They diagnosed and fixed it right away, had to replace the backup battery since it was shot. The total came to 330 € for parts and labor, which included sorting out the "Battery discharged due to ageing" issue they found during inspection. Everything's been running smoothly since the repair, no more alarm glitches or warning lights on the dash. The system arms and disarms perfectly now. I'd say what you experienced is pretty standard for these BMWs once the backup battery starts failing. Just make sure they use genuine parts like I mentioned before, it's worth the extra cost to avoid future headaches. By the way, the repair cost can vary a bit depending on labor rates and if they find any other small issues while they're in there. But at least now you've got peace of mind knowing the security system is working as it should!

Thanks for sharing your experience! I actually went ahead and got mine fixed last week. Wanted to give you guys an update on how it went. Took it to a different mechanic this time, one specializing in BMW repairs. They immediately spotted the backup battery issue and replaced it. The whole thing cost me about 300 for parts and labor, which seems fair compared to what you paid. The funny part was when they were working on it, the mechanic accidentally set off the alarm while testing it, and everyone in the shop jumped! At least we knew it was working again, right? But seriously, it's been running perfectly since the fix. The alarm arms properly now, and all those annoying warning messages have disappeared from my dashboard. Really appreciate everyone's input on this. It helped me feel more confident about getting it repaired instead of putting it off. Definitely learned my lesson about regular maintenance checks too. Think I'll stick with this new mechanic from now on, they seem to know their stuff!