Yep. Same thing is happenning to my X5. My neighbor is just about to kill me. I'm taking it in to the dealer tomorrow. It's just randomly goes off after locking the car. I notice that it does happened more often when it's windy outside. Never heard of a GT1 tester before. I'll tell the dealer right away to hook it up to the GT1 tester. Most likely a fault sensor somewhere. Hopefully it won't be too expensive to repair.

thanks