mine does the same thing ..............auo code on glovebox sticker , stating if you have it or not .

 

I found this thread, and have the exact same problem with a 2002 Silverado. The high beam->cycle key procedure causes immediate lock cycling, and then about 30 seconds later, the locks cycle again. No luck programming keys after this procedure.

The "unlock button->cycle key" causes a weak sort of "I'm trying to cycle the locks but failing" response, similar to what another poster reported. I'm baffled by this, since just a week ago the original key fob worked, until it got stepped on. So I know the keyless entry has the potential to work, but I cannot get an aftermarket fob to program, and it seems like my truck isn't even property entering programming mode.

Hope someone figures this one out.

Edit: After doing some more digging, it appears the high beam->cycle key procedure is to disable or enable the automatic locking or unlocking when shifting to drive or park. It is not related to programming.

Edit2: Success! So it turns out that I had the wrong replacement key fob. There are multiple fobs on Amazon/Ebay that claim to be for my Silverado and year, but you must order the fob that matches the original code for your vehicle. On mine I had an original, non-working fob, and could read the code off the back of it (15042968). I did the "hold unlock->cycle key" procedure, got a weak "trying to cycle" response (which I previously thought indicated that it was NOT entering programming mode), held lock/unlock buttons down on the remote for about 10 seconds and BAM the locks cycled, and the fob works. Hope this helps someone -- a weak "not really cycling locks" response, may still indicate entering programming mode, you just need to make sure you get the right replacement fob.