Cadillac 2011 DTS Owner's Manual page 181

Press the ACC button or turn the ignition off.
There are three additional messages that may appear
on the DIC. They are SERVICE RADAR CRUISE,
RADAR CRUISE NOT READY and CLEAN RADAR.
These messages will appear to indicate a problem with
the ACC. See DIC Warnings and Messages on
page 4 62 for more information.
The radar can become blocked by snow, ice, or dirt.
If so, you may need to turn off the engine and clean the
lens. Remember, do not use ACC in icy conditions,
or when visibility is low, such as in fog, rain or snow.
The emblem/lens is located in the center of the grille.
To clean the emblem/lens, wipe the surface with a soft
cloth. After cleaning the emblem/lens, try to engage the
ACC. If you are unable to do so, see your dealer.
It controls the following systems:
Headlamps
Taillamps
Parking Lamps
License Plate Lamps
Instrument Panel Lights
Fog Lamps
The exterior lamps control
is located on the
instrument panel to the
left of the steering wheel.
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