Panic Alarm goes off when opening driver door.
 

I have a 2002 Chevy Sierra 2500 Duramax Diesel truck. When I open the drivers side door the alarm goes off. I can open the door to get out of the truck after driving it and it doesn't do it but after I let the truck set for about five minutes I open the door and it goes on again. Does anyone have any easy fix for this? I have tried putting the key in the lock on the door and that stops it temporarily until next time I open the door.