The interior lamps will turn on if you open the door when it is dark enough outside. When you close the door with the ignition off, the interior lamps will stay on for up to 25 seconds or until the ignition is turned to an on position. When the lamps turn off as a result of the 25 second timer or the ignition switch being turned on, the lighting will deactivate by way of the theater dimming effect. Locking the doors will override the delayed entry lighting feature and the lamps will turn off right away.