The manual may not help, because you never know where the installer put the sensitivity adjustment knob. If he did it right, it’s under the dash, probably somewhere behind the glove box area. It’ll be a little knob. Sounds like it’s turned up way too sensitive. Twist it counter-clockwise a bit. You’ll need to do a lot of experimentation to figure out what setting you want. The alarm should go off if you give the A-pillar a fairly good whack (not, obviously, enough to dent it) with the side of your fist (from the outside), but not if you just lightly smack it with the flat of your hand.