auto door locks

I have a 2000 Silverado with 97,000 miles. No trouble with vehicle until about a week ago. Seems that my door locks will not operate with fob. Changed battery and tried factory re-set. No responce. Went to owners manual and tried re-set with turn signal and key off/on steps. No responce. Door locks will not lock automatically with fob or when travel is greater that 15 mph. If I select lock button on fob, horn will sound. If I select unlock on fob, lights will flash as before to indicate open/unlock.
All dealer wants is to have me bring in and hook to their computer.
I believe this is a simple problem. Just need feedback. Anyone else have this happen to them?

do the locks work with the button? If not, then it is the truck, maybe computer, maybe a door lock relay out? If it works with the button, then the output on the keyless entry has gone out. The question that answers that is... does it not lock or unlock? Or just not lock... or just not unlock. I will be able to tell you more when I know some more from you.

just to add....do the doors lock/unlock with the power lock switch on the door...just another step to diagnose whether its the remote receiver or the power lock circuit itself.....just my $0.02