2009 GMC Envoy Remote Programming Procedure:
NOTE: Before initiating programming mode, have in possession all transmitter you want to use on the car, including old ones you want to keep working. When you program the transmitter, all previous codes will be removed from the memory. The other keyfobs will not be functional until you program the fobs again.
1. Shut all vehicle doors, all windows closed, wait for dome light to go 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. Move the ignition switch to the ON position (as far as you can go WITHOUT starting the engine).
6. Turn the ignition switch to the OFF position.
7. Flip the ignition switch to the ON position.
8. Flip 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 by itself.
10. Hold down the LOCK and UNLOCK buttons on the transmitter at the same time until the door locks cycle. This step may take up to Half a minute.
11. Repeat step 10 for every additional transmitter(including any existing keyfobs).
12. Flip the ignition switch to the ON position in order to quit the keyfob learning function.