How do you program door lock on 2003 avalanche?

To program the door locks on a 2003 Chevrolet Avalanche, first, insert the key into the ignition and turn it to the "On" position without starting the engine. Then, press and hold the "Unlock" button on the driver's side door while simultaneously pressing the "Lock" button three times. Release both buttons, and the door locks should cycle to confirm the programming. If you are programming a new key fob, you may need to refer to the vehicle's owner manual for specific instructions as it can vary slightly.