I have a used '05 Express with an extra key fob that is not programmed. Anyone with experience setting these up? The dealer I bought from is too far away to drive there just for this and others want $50 to do the job. Thanks in advance for any help/suggestions.

 

I can't remember exactly how to do it but I'll give it a shot.

The key eithe doesn't have to be on or it does have to be on. Try both if one doesn't work.
After that. Press the unlock door button once to make the doors unlocked.
Then press and hold the lock door button until the doors unlock and then relock.
At that time on the key fob press and hold both the unlock and the lock buttons.
Once it programs it will then unlock and lock again.

Now I'm not sure if that's right and I may have somethings backwards but play with it trying different things. Also you may have reprogram the other key fob also when you program the one that doesn't work.

 

Bad news is this can only be done with the GM scanner tool. This model of truck does not have the "self programing" setup built in. Take all the remotes to the dealer when reprograming as everything is reset to match.