after a couple searches it appears it would be the BCM Pontiac Repair: 2004 grand prix door and trunk locks not working., trunk locks, ac delco

http://www.grandprixforums.net/2008-...lem-45782.html
My power door locks in my 04 Grand Prix GTP quit working. What and how do I fix that? Why did that happen? - The Car Connection
http://www.grandprixforums.net/no-au...ock-40860.html

Sorry I'm not much use on this one