2002 Cadillac DeVille Owner's Manual - Page 123

Light Sensor Exterior Lighting Battery Saver If the manual parking lamps or headlamps have been left on, the exterior lamps will turn off approximately ten minutes after the ignition is turned to OFF. This protects against draining the battery in case you have accidentally left the headlamps or parking lamps on. The battery saver does not work if the headlamps are turned on after the ignition switch is turned to OFF. If you need to leave the lamps on for more than 10 minutes, use the exterior lamp control to turn the lamps back on. To delay the lamps from turning off, see "Twilight Sentinel" in the Index. The light sensor for the DRL and the Twilight Sentinel is located in the center of the front defogger grille. If you cover the sensor, it will read "dark" and the exterior lamps or the HEADLAMPS SUGGESTED message will be on whenever the ignition is on. 2-55