Cadillac 2004 DeVille - Manual (Page 147)

Light Sensor
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 displayed whenever the ignition is on.
Exterior Lighting Battery Saver
If the manual parking lamps or headlamps have been
left on, the exterior lamps will turn off approximately
10 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
® ” listed previously in this section.
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