Chevrolet Impala Owner's Manual page 258

9-50 Driving and Operating
Tailgating Alert
The vehicle ahead indicator will
display amber when you are
following a vehicle ahead much too
closely.
Selecting the Alert Timing
With Adaptive Cruise Control
Without Adaptive Cruise Control
Press the collision alert/following
gap button on the steering wheel to
set the FCA timing to Far, Medium,
Near, or on some vehicles, Off. The
first button press shows the current
setting on the DIC. Additional button
presses will change this setting. The
chosen setting will remain until it is
changed and will affect the timing of
both the Collision Alert and the
Tailgating Alert features. The timing
of both alerts will vary based on
vehicle speed. The faster the
vehicle speed, the farther away the
alert will occur. Consider traffic and
weather conditions when selecting
the alert timing. The range of
selectable alert timing may not be
appropriate for all drivers and
driving conditions.
Changing the FCA timing setting
automatically changes the following
gap setting (Far, Medium, or Near)
for the Adaptive Cruise Control
(ACC) feature.