Cadillac 2009 STS-V - Manual (Page 194)

Exterior Lighting Battery Saver
If the parking lamps or headlamps have been left on,
the exterior lamps will turn off about 10 minutes after the
ignition is turned 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 is
turned 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.
Instrument Panel Brightness
Press the center knob on
the DIC control panel to
extend. Then turn the knob
clockwise to brighten the
lights or counterclockwise
to dim them. If the knob
is turned completely
clockwise, the interior
lamps turn on.
Base Level Shown,
Uplevel Similar
3-40