I realize for my 2001 Silverado they changed fob/part numbers that are not interchangeable. I have tried to program both types of fobs and neither work. I can get my truck in program mode easy enough, but then no response from fob when I attempt to program. I checked for a fuse and there is a relay associated with such a thing. I can feel a clicking in the relay so everything appears to be in working order on the truck's end. Am I missing something?