I have a 01 Tahoe LT. It was purchased without a key fob for power locks. I picked up a couple online and tried to program them on the 01 with no luck. I figured it was maybe the remotes do I tried to program them in my 00 Tahoe and they worked just fine. I held the "unlock" button and cycled the key twice. The 01 gave me the "lock and unlock" feedback telling me that it was in program mode but when I held the buttons on the remote, I never got the truck to take the remote's signal. I held the buttons down for probably a minute.

I'm a bit lost on this one... Any ideas on where to start? I tried a search but everything I found didn't really help with this situation.

 

You may need to find someone with a Tech 2 or equivalent scan tool.

They can see what going when they try to relearn the new remotes. When you fill the 4 available slots, sometimes you have to clear them out in order for new ones to take.