I have a 2007 997, about 6 months old. Last night the alarm goes off in my garage. Everything checked out OK, and it turned off by itself. Now three times today the alarm has gone off for no reason. Anyone had this problem before, and know the cause? Maybe I can point service in the right direction. Thanks.

 

Same thing happened to me last week; never before and not since. I figured an insect must have got inside the car and it's flying about set things off.

 

Try arming twice (I think that disables the interior sensor) and see if it still goes off. If it doesn't then maybe you've narrowed it down to just the interior sensor.

 

Never discount Beelzebub, Dude.

 

I've had the alarm go off randomly for the whole 2 1/2 years I've had the car. I started a thread about it a year or so ago, and others had experienced it, too. The dealer just shrugs; apparently there is no sensitivity adjustment. It is not being set off by a phone or anything else left inside the car.

Eventually the high note of the horn (which is what sounds the alarm) quit working; there was just a thread here about this common issue. I can't help but think the two issues are somehow related.