GMC Sierra 2014 Owner's Manual page 329

visibility. FCA will not detect another
vehicle ahead until it is completely
in the driving lane.
Warning
FCA does not provide a warning
to help avoid a crash, unless it
detects a vehicle. FCA may not
detect a vehicle ahead if the FCA
sensor is blocked by dirt, snow,
or ice, or if the windshield is
damaged. It may also not detect a
vehicle on winding or hilly roads,
or in conditions that can limit
visibility such as fog, rain,
or snow, or if the headlamps or
windshield are not cleaned or in
proper condition. Keep the
windshield, headlamps, and FCA
sensors clean and in good repair.
Collision Alert
When your vehicle approaches
another vehicle too rapidly, six red
lights will flash on the windshield. In
addition, either eight beeps will
sound from the front, or both sides
of the Safety Alert Seat will pulse
five times.
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
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