GMC Acadia Owner's Manual page 249

Detecting the Vehicle Ahead
The green vehicle ahead indicator
will appear when a vehicle is
detected ahead. Whenever this
indicator does not appear, FCA will
not respond. The indicator may
disappear on curves, highway exit
ramps, or hills, or due to poor
visibility. The FCA system 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,
Warning (Continued)
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.
Tailgating Alert
The green vehicle ahead indicator
will turn amber if following another
vehicle much too closely.
(Continued)
Driving and Operating
Collision Alert
Without HUD
With HUD
When your vehicle approaches
another vehicle too rapidly, this red
FCA display will flash and eight
beeps will sound from the front.
When this occurs, the brake system
prepares for driver braking to occur
more rapidly. Continue to apply the
brake pedal as the driving situation
dictates.
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