See also:

Using Universal Home Remote
Press and hold the appropriate button for at least half of a second. The indicator light will come on while the signal is being transmitted. ...

Programming with a Recognized Transmitter (Keyless Access Vehicles Only)
A new transmitter can be programmed to the vehicle when there is one recognized transmitter. To program, the vehicle must be off and all of the transmitters, both currently recognized and new, mus ...

Warranty
OnStar equipment may be warranted as part of the new-vehicle limited warranty. The manufacturer of the vehicle furnishes detailed warranty information. ...