If the dome lamp is to DOOR, the lamps inside your vehicle will come on when any door is opened. In addition, the light will come on when the Remote Keyless Entry Unlock button is on. It will stay on for 20 seconds or until a door is opened. After the door is opened the light will remain on and stay on for 20 seconds after the doors are closed, or until you put the key in the ignition and turn the key to RUN. The light will then gradually dim until it is no longer lit.