2001 Suburban Antithief horn alarm

Does anyone have a solution for fixing the horn alarm? Everytime I unlock and open the door, the alarm sounds off. I have to crank the truck up each and everytime to make it stop. It doesn't matter which door it is, it does it everytime. I am using the original keys. The fuse is good. It started about a month ago and it's getting very annoying. Especially when I have to leave early in the morning to go to work. Anybody's input would be greatly appreciated.

A tempt fix would to be put a toggle switch on the horn BUT.
To find the problem you need to get into and check the body computer with a good full capable body computer scanner.
Post back any codes it may have.
MT