GM Service Manual Online
For 1990-2009 cars only

Key Coding Procedure

Important: 

   • To initiate, this procedure requires that a learned key be available.
   • This procedure adds keys only. The procedure does not erase previously learned keys.
   • If more than one key is to be learned, immediately precede each new key with a learned key.

  1. With a previously learned key, turn ON the ignition, with the engine OFF.
  2. Turn OFF the ignition and remove the key.
  3. Within 15 seconds of turning OFF the ignition, insert the key to be learned and turn ON the ignition. The vehicle has now learned the new key.