GM Service Manual Online
For 1990-2009 cars
Makes 🢒 Chevrolet 🢒 2004 🢒 Tahoe - 2WD 🢒 Accessories 🢒 Theft Deterrent - Immobilizer - Some Export Vehicles 🢒 Adding Keys

Important: 

   • You may add up to 10 additional master keys or valet keys using this procedure if 2 learned master keys are available. If 2 learned master keys are not available the 10 minute relearn procedure must be performed. Refer to Programming Theft Deterrent System Components .
   • If more than one valet key is to be learned, immediately precede each valet key by 2 learned master keys.
   • 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.

  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 10 seconds insert a second previously learned master key. Turn ON the ignition with the engine OFF.
  4. Turn OFF the ignition and remove the key.
  5. Within 10 seconds insert the key to be learned. Turn ON the ignition with the engine OFF. The vehicle has now learned the new key.