Cadillac 2010 DTS Owner's Manual page 185

The alert symbol flashes and a warning beep sounds
when driver action may be required. If ACC is engaged,
the alert symbol will flash when:
ACC cannot apply sufficient braking because you
are approaching a vehicle too rapidly.
The vehicle speed drops below about
32 km/h (20 mph).
The ACC alert symbol is
located on the display at
the top of the instrument
panel to the right of the
driver.
A temporary condition prohibits ACC from
operating. See DIC Warnings and Messages on
page 4 66 for more information.
A malfunction is detected in the system. See DIC
Warnings and Messages on page 4 66 for more
information.
See Defensive Driving on page 5 2.
Adaptive Cruise Control has only limited braking
ability to slow your vehicle. In some cases,
Adaptive Cruise Control may not have time to
slow your vehicle enough to avoid a collision.
Be ready to take action and apply the brakes
yourself. See Defensive Driving on page 5 2.
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