2007 GMC Sierra 1500 Pickup Owner's Manual - Page 121

To unlock the door from the outside, use the Remote Keyless Entry (RKE) transmitter or the key. To unlock or lock the door from the inside, slide the manual lever forward or rearward. Power Door Locks If your vehicle has this power door lock switch, press the raised side of the switch, with the lock symbol, on either front door to lock all the doors at once. Press the recessed side of the switch with the unlock symbol, to unlock all the doors at once. 121