All doors lock but the tailgate won't

[pompeys940]

All of a sudden all of my lights started staying on and the tailgate won't lock. All other doors will lock when I hit lock button twice. I use to hit the door lock once and hear the 3 beeps and then the door would lock; all of them. I think there is some kind of series of functions that I must perform to reset this thing....Any help would be great.

[rodeo02]

Do you have a door adjar icon lit up on the dash when this occurs? I'm wondering if one of the 5 switches isn't being made. Instead of pin switches in the jambs, GM uses something internal to the door latches.

Joel