I have 2003 Suburban, it came with 2 key fobs and both stopped working so we took it to the dealership and they said they were the only ones who could do it, and we would have to buy the fobs in sets of 2 (at ~$100 each plus their service fee). We said hell no and went to Canadian Tire, of course they had them for $80 so bought one to try programming ourselves. The way I read the instructions is that when I programmed the new remote the truck wiped the previous two remotes from memory. So now we have one remote programmed to the truck. My question is, is there a limit on the number of fobs we can program to the vehicle? Is it two or can we get three or four fobs?

 

Found this on Google. Looks like you can program 4. I have also bought them on Ebay for about $30.00 and they were the GM ones.

Obtain all remote transmitters.
Close all doors.
Insert key into ignition, do not turn ignition switch.
Press and hold door lock switch in the unlock position.
Switch ignition ON, OFF, ON, OFF.
Release door lock switch.
Doors will lock and unlock, indicating programming mode activated.
To program remote transmitter proceed as follows:
Simultaneously press and hold transmitter LOCK and UNLOCK buttons.
Doors will lock and unlock, indicating remote transmitter programmed.
Repeat above procedure for each remote transmitter.
Switch ignition ON to exit programming mode.
NOTE: Existing remote transmitter memory positions will be overwritten.
NOTE: A maximum of 4 remote transmitters can be programmed.

 

up to 4 for that era of vehicle

 

Ours went out on our '04 HHR. Turns out it was the battery. Then on one of them, the bracket that holds the battery separated from the body of the circuit board so I soldered it back on.

Also what happens is that the little contacts inside the rubber cover wear out and quit making contact. So then you can buy the rubber covers with new contacts from O'Reillys and Auto Zone. Lot cheaper than buying new circuit boards that need programming.