GMC Yukon 2021 Owner's Manual page 258

or both sides of the Safety Alert Seat (if
equipped) will pulse five times. See
Collision/Detection Systems under Vehicle
Personalization 0 125
See Defensive Driving 0 214.
Approaching and Following a Vehicle
The vehicle ahead indicator is in the
instrument cluster and HUD, if equipped.
It only displays when a vehicle is detected
in your vehicle s path moving in the same
direction. If this symbol is not displaying,
ACC will not respond to or brake for vehicles
ahead.
ACC automatically slows the vehicle down
and adjusts vehicle speed to follow a
detected vehicle ahead at the selected
following gap. The vehicle speed increases or
decreases to follow a detected vehicle in
front of your vehicle when that vehicle is
traveling slower than your vehicle set speed.
It may apply limited braking, if necessary.
When braking is active, the brake lamps will
come on. The automatic braking may feel or
sound different than if the brakes were
applied manually. This is normal.
Passing a Vehicle While Using ACC
If the set speed is high enough, and the left
turn signal is used to pass a vehicle ahead
in the selected following gap, ACC may
assist by gradually accelerating the vehicle
prior to the lane change.
Warning
When using ACC to pass a vehicle or
perform a lane change, the following
distance to the vehicle being passed may
be reduced. ACC may not apply sufficient
acceleration or braking when passing a
vehicle or performing a lane change.
Always be ready to manually accelerate
or brake to complete the pass or lane
change.
Stationary or Very Slow-Moving Objects
Warning
ACC may not detect and react to stopped
or slow-moving vehicles ahead of you. For
example, the system may not brake for a
Driving and Operating
Warning (Continued)
vehicle it has never detected moving. This
can occur in stop-and-go traffic or when a
vehicle suddenly appears due to a vehicle
ahead changing lanes. Your vehicle may
not stop and could cause a crash. Use
caution when using ACC. Your complete
attention is always required while driving
and you should be ready to take action
and apply the brakes.
Irregular Objects Affecting ACC
ACC may have difficulty detecting the
following objects:
Vehicles with cargo extending from the
back end.
Non-standard shaped vehicles, such as
vehicle transport, vehicles with a side car
fitted, or horse carriages.
Objects that are close to the front of your
vehicle.
ACC Automatically Disengages
ACC may automatically disengage and the
driver will need to manually apply the
brakes to slow the vehicle if:
The sensors are blocked.
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