Chevrolet 2015 Impala Owner's Manual page 249

9-40 Driving and Operating
ACC Automatically Disengages
ACC may automatically disengage
and the driver will need to manually
apply the brakes to slow the
vehicle when:
The sensors are blocked.
The Traction Control System
(TCS) or electronic stability
control system has activated or
been disabled.
There is no traffic or other
objects to detect.
There is a fault in the system.
A message indicating that the cruise
is disengaging will appear on the
DIC and the ACC active symbol will
not be displayed when ACC is no
longer active.
Notification to Resume ACC
ACC will maintain a following gap
behind a detected vehicle and slow
your vehicle to a stop behind that
vehicle.
If the stopped vehicle ahead has
driven away and ACC has not been
resumed, the vehicle ahead symbol
will flash as a reminder to check
traffic ahead before proceeding. In
addition, three beeps will sound.
See Go Notifier under Collision/
Detection systems in Vehicle
Personalization on page 5-38.
When the vehicle ahead drives
away, press RES+ or the
accelerator pedal to resume cruise
control. If stopped for more than
two minutes or if the driver door is
opened, the ACC automatically
applies the Electric Parking Brake to
hold the vehicle. The Electric
Parking Brake status light will turn
on. See Parking Brake on
page 9-29. To resume ACC and
release the Electric Parking Brake,
press the accelerator pedal. ACC
can be resumed when the vehicle is
travelling greater than 25 km/h
(16 mph).
A DIC warning message may
display indicating to shift to P (Park)
before exiting the vehicle. See
Vehicle Messages on page 5-28.
Warning
If ACC has stopped the vehicle,
and if ACC is disengaged, turned
off, or canceled, the vehicle will
no longer be held at a stop. The
vehicle can move. When ACC is
holding the vehicle at a stop,
always be prepared to manually
apply the brakes.
Warning
Leaving the vehicle without
placing it in P (Park) can be
dangerous. Do not leave the
vehicle while it is being held at a
stop by ACC. Always place the
vehicle in P (Park) and turn off
the ignition before leaving the
vehicle.