GM Service Manual Online
For 1990-2009 cars only

Important: 

   • To initiate, this procedures requires that a learned master key be available.
   • A total of 10 master keys or valet keys may be programmed to a single vehicle.
   • This procedure adds keys only. The procedure does not erase previously learned keys.
   • The keys to be learned must duplicate the mechanical cut of the current key.
   • If more than one valet key is to be learned, immediately precede each valet key with a learned master key.

  1. With a previously learned master key, turn ON the ignition, with the engine OFF.
  2. Turn OFF the ignition and remove the key.
  3. Within 4 seconds insert the key to be learned.

Turn ON the ignition with the engine OFF. The vehicle has now learned the new key.