I have a 2003 Silverado K1500 extended cab. Left door switch module failed completely about 2 years ago. Ordered new one from dealer was over $150 IIRC. They said it would also cost over $100 to reprogram it for remote entry. Replaced it myself and everything was working again including the remote entry key fobs.
I think the remote entry may work through the right side door module.
As for the fobs, I had to replace one this past fall. It was the one used most often and was failing to lock and unlock doors part of the time. Got a new one at Ace Hardware with instructions for resynchronizing the new fob. Only problem was the other fob stopped working. However, figured out all fobs old and new, must be resynchronized at the same time.
Don't know if the dealer lied about reprogramming the remote entry to make more money off me or if it actually needs to be done when replacing the right side module. May have to do with the vehicle computer.
