I just purchased a 2000 Silverado. It didn't come with any key fobs. I checked the glove box RPO sticker for an AU0 code to verify it would work with a FOB. Bought 2 from Ebay. Hold unlock button drivers door and cycle switch 2 times. Hold down lock/unlock on FOB. The door locks cycles like it picks up the fobs. Cycle key to leave program mode. Then the FOB's don't work. I tried different combinations of cycling the key different numbers of times but no go. Tried pulling in turn signal lever with key cycling and it repeats everything just as it should but still FOBs don't work. So I just bought another fancier FOB from Ebay for 2000 Silverado with the key made into the FOB. It programs just like the others but doesn't function either. I guess I need to replace the passenger door control module? I know the passenger door control modules reads the FOB and then instructs the Body control module to unlock doors, cycle headlights and toot horn. Is the passenger door control module the assembly with the power window button and door lock button? Or is it a separate module located somewhere else? I'm lost at this point. does anybody have any ideas of what I need to do? How to troubleshoot? Thanks. Lonnie