Cadillac 2011 STS Owner's Manual page 209

Adaptive Cruise Control may not detect and
react to stationary or slow moving vehicles or
other objects ahead of you. You could crash into
an object ahead of you. Do not use Adaptive
Cruise Control when approaching stationary or
slow moving vehicles or other objects.
Adaptive Cruise Control may not detect and react
to stationary or slow-moving vehicles or other
objects ahead of you. Your vehicle may accelerate
toward objects, such as a stopped vehicle that
suddenly appears after the lead vehicle changes
lanes. Your complete attention is always required
while driving and you should be ready to take
action and apply the brakes.
If your speed falls below 40 km/h (25 mph) while
following a vehicle ahead, Adaptive Cruise Control will
begin to disengage. The driver alert symbol on the HUD
will flash and the warning beep will sound. The driver
must take action since Adaptive Cruise Control will not
slow the vehicle to a stop.
If the HUD is turned off when Adaptive Cruise Control is
engaged, it will begin to disengage. A warning beep
sounds and the message RADAR CRUISE NOT
READY appears on the Driver Information Center (DIC).
See DIC Warnings and Messages on page 4 76 for
additional information. If Adaptive Cruise Control was
braking when the HUD is turned off, the braking will
continue briefly.
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