2002 S60 2.4T

Alarm goes off periodically..have cycled through the Lock/Unlock on the key control several times and started/stopped engine.

Car is sitting in garage, doors unlocked...but the alarm horn blares every so often....

any ideas? car does not have an option button on dash to turn off alarm system...

 

Not sure this helps, but my battery went dead in my 05 S60 and when I got jumped off my alarm went off several times despite my key in the ignition and me hitting the unlock and lock buttons like mad to try and turn it off. It finally went off but on the ride home it kept going off while I was driving and at one point there was no audible sound but my hazard lights flashed for about 3 miles non-stop then suddenly they turned themselves off. When I got home I disconnected the battery and reconnected it and the alarm worked like normal. Maybe try that?

Thanks,
Casey