2003 GMC Yukon Owner's Manual - Page 102

To lock the door from the inside, slide the lever rearward. To unlock the door, slide the lever forward. Press the recessed side of the switch with the unlock symbol, to unlock all the doors at once. If your vehicle has the delayed locking feature, see "Delayed Locking" later in this section. If your vehicle has this power door lock switch, press the bottom of the switch on either front door to lock all the doors at once. Power Door Locks If your vehicle is equipped with power door locks, press the raised side of the switch, with the lock symbol, on either front door to lock all the doors at once. Press the top of the switch to unlock all the doors at once. The power door locks will operate at any time even when the ignition is off. Operating the power locks may interact with the theft-deterrent system (if equipped). See Content Theft-Deterrent on page 2-16. 2-8