I have a 2007 Chevy Silverado LT (crew cab). The Left rear auto door lock does not work from remote key, passenger side lock, or left rear door lock. It does not lock or unlock Automatically, It Appears, occasionally, I have noticed when I open and close LR door. LR lock begins to work again. Then after a few days LR auto lock stops working.

Any Thoughts from anybody?
Frisco Ron