2005 GMC Envoy Remote Programming Procedure:
IMPORTANT: Before entering fob learning mode, have with you all remote you want to use on the vehicle, including old ones you want to keep working. At the time you program the transmitter, all previous learned keyfobs will be taken out from the memory. The other remotes will not be functional until you program the fobs again.
1. Shut all vehicle doors, all windows closed, wait for dome light to turn off.
2. Put the key into the ignition.
3. Press and Hold the power UNLOCK button on the driver’s door panel-do not release until step 9.
4. Perform steps 5-8 quickly.
5. Switch the ignition switch to the ON position (as far as you can go WITHOUT activating the engine).
6. Switch the ignition switch to the OFF position.
7. Turn the ignition switch to the ON position.
8. Move the ignition switch to the OFF position.
9. Release the power unlock button on the door panel. The vehicle will lock and unlock the doors automatically.
10. Hold down the LOCK and UNLOCK buttons on the transmitter at the same time until the door locks lock and unlock. This step may take up to Half a minute.
11. Repeat step 10 for each and every additional keyfob(including any existing remotes).
12. Move the ignition switch to the ON position in order to exit the keyfob learning method.