GM did not provide a way to do this without a Tech II scanner but here is the process if you have a scanner available.
All transmitters that are to be recognized by the remote control door lock receiver (RCDLR) must be programmed in a single programming sequence. If the system is placed in program mode, all previously programmed transmitters will be erased upon receipt of the programming signal from the first transmitter.
Up to 4 transmitters can be programmed. Do not operate or program the transmitters in the vicinity of other vehicles that are in the keyless entry program mode. This prevents the programming of the transmitters to the incorrect vehicle. The order in which the transmitters are programmed is important. The first transmitter programmed will be transmitter #1, and the second transmitter programmed will be transmitter #2. Use care to program the transmitters correctly.
The scan tool must stay connected until all of the transmitters are programmed. All doors must be closed to perform this function.
- Install CANDI module.
- Install a scan tool.
- Turn ON the ignition with the engine OFF.
- With the scan tool, select Vehicle Control Systems.
- Select Computer/Integrating Systems.
- Select the proper engine size.
- Select Module Setup.
- Select Body Control Module (BCM).
- Select Program Key Fobs.
- Follow scan tool on screen instructions.
- Remove the scan tool.
- Exit the vehicle. Attempt to lock/unlock the doors to verify the programming.
- Operate the transmitter functions in order to verify correct system operation.