GMC ACADIA 2021 Owner's Manual

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-14608671) - 2021 - CRC - 10/26/20
230 Driving and Operating
Automatic Engine Grade Braking
Automatic Engine Grade Braking assists
when driving downhill. It maintains vehicle
speed by automatically implementing a shift
pattern that uses the engine and the
transmission to slow the vehicle. The system
will automatically command downshifts to
reduce vehicle speed. The normal shift
pattern will return once the vehicle is on a
low grade or when the accelerator pedal is
pressed.
While in the Electronic Range Select (ERS)
mode, grade braking is deactivated, allowing
the driver to select a range and limiting the
highest gear available. Grade braking is
available for normal driving and in
Tow/Haul Mode.
SeeAutomatic Transmission 0220.
7Off-Road (AWD Only) : Use this mode
for off-road recreational driving. Choosing
Off-Road Mode also engages AWD Mode. For
more information on Off-Road Mode, see
Off-Road Driving 0203.
Cruise Control
{
Warning
Cruise control can be dangerous where
you cannot drive safely at a steady
speed. Do not use cruise control on
winding roads or in heavy traffic.
Cruise control can be dangerous on
slippery roads. On such roads, fast
changes in tire traction can cause
excessive wheel slip, and you could lose
control. Do not use cruise control on
slippery roads.
With cruise control, a speed of about
40 km/h (25 mph) or more can be
maintained without keeping your foot on
the accelerator. Cruise control does not work
at speeds below about 40 km/h (25 mph).
If the StabiliTrak/Electronic Stability Control
(ESC) system begins to limit wheel spin
while using cruise control, the cruise control
automatically disengages. See Traction
Control/Electronic Stability Control 0226.
If a collision alert occurs when cruise control
is activated, cruise control is disengaged. See
Forward Collision Alert (FCA) System 0245. When road conditions allow the cruise
control to be safely used, cruise control can
be turned back on.
Turning off the TCS or StabiliTrak/ESC
system will disengage the cruise control.
If the brakes are applied, cruise control
disengages.
J:
Press to turn the system on and off.
A white indicator appears in the instrument
cluster when cruise is turned on.
RES+ : If there is a set speed in memory,
press briefly to resume to that speed or
press and hold to accelerate. If the cruise
control is already active, use to increase
vehicle speed.

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-14608671) - 2021 - CRC - 10/26/20
Driving and Operating 231
SET−:Press briefly to set the speed and
activate cruise control. If the cruise control is
already active, use to decrease vehicle
speed.
*: Press to disengage cruise control
without erasing the set speed from memory.
Setting Cruise Control
If
Jis on when not in use, SET− or RES+
could get pressed and go into cruise when
not desired. Keep
Joff when cruise is not
being used.
1. Press
J.
2. Get up to the desired speed.
3. Press and release SET−. The desired set speed briefly appears in the instrument
cluster.
4. Remove your foot from the accelerator.
When the cruise control has been set to the
desired speed, a green cruise control
indicator appears on the instrument cluster.
Resuming a Set Speed
If the cruise control is set at a desired speed
and then the brakes are applied or
*is
pressed, the cruise control is disengaged
without erasing the set speed from memory. Once the vehicle speed reaches about
40 km/h (25 mph) or more, press RES+
briefly. The vehicle returns to the previous
set speed.
Increasing Speed While Using Cruise Control
If the cruise control system is already
activated:
.Press and hold RES+ up until the desired
speed is reached, then release it.
.To increase vehicle speed in small
increments, briefly press RES+. For each
press, the vehicle goes about 1 km/h
(1 mph) faster.
The speedometer reading can be displayed
in either English or metric units. See
Instrument Cluster (Base and Midlevel) 097
or
Instrument Cluster (Uplevel) 0100. The
increment value used depends on the units
displayed.
Reducing Speed While Using Cruise Control
If the cruise control system is already
activated:
.Press and hold SET− until the desired
lower speed is reached, then release it.
.To decrease the vehicle speed in small
increments, briefly press SET−. For each
press, the vehicle goes about 1 km/h
(1 mph) slower.
The speedometer reading can be displayed
in either English or metric units. See
Instrument Cluster (Base and Midlevel) 097
or
Instrument Cluster (Uplevel) 0100. The
increment value used depends on the units
displayed.
Passing Another Vehicle While Using Cruise
Control
Use the accelerator pedal to increase the
vehicle speed. When you take your foot off
the pedal, the vehicle will slow down to the
previous set cruise speed.
While pressing the accelerator pedal or
shortly following the release to override
cruise, briefly applying SET− will result in
cruise set to the current vehicle speed.
Using Cruise Control on Hills
How well the cruise control will work on
hills depends upon the vehicle speed, load,
and the steepness of the hills. When going
up steep hills, you might have to step on
the accelerator pedal to maintain your
speed. When going downhill, you may have

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-14608671) - 2021 - CRC - 10/26/20
232 Driving and Operating
to brake or shift to a lower gear to keep
your speed down. If the brake pedal is
applied, cruise control disengages.
Ending Cruise Control
There are four ways to end cruise control:
.Step lightly on the brake pedal.
.Press*.
.Shift the transmission to N (Neutral).
.PressJ.
Erasing Speed Memory
The cruise control set speed is erased from
memory if
Jis pressed or if the ignition is
turned off.
Adaptive Cruise Control
(Advanced)
If equipped with Adaptive Cruise Control
(ACC), it allows the driver to select the
cruise control set speed and following gap.
Read this entire section before using this
system. The following gap is the following
time between your vehicle and a vehicle
detected directly ahead in your path,
moving in the same direction. If no vehicle
is detected in your path, ACC works like regular cruise control. ACC uses camera and
radar sensors. See
Radio Frequency
Statement 0371.
If a vehicle is detected in your path, ACC can
apply acceleration or limited, moderate
braking to maintain the selected following
gap. To disengage ACC, apply the brake.
If ACC is controlling your vehicle speed
when the Traction Control System (TCS) or
StabiliTrak/Electronic Stability Control (ESC)
system activates, the ACC may automatically
disengage. See Traction Control/Electronic
Stability Control 0226. When road
conditions allow ACC to be safely used, the
ACC can be turned back on.
Disabling the TCS or StabiliTrak/ESC system
will disengage and prevent engagement
of ACC.
ACC can reduce the need for you to
frequently brake and accelerate, especially
when used on expressways, freeways, and
interstate highways. When used on other
roads, you may need to take over the
control of braking or acceleration more
often.
{Warning
ACC has limited braking ability and may
not have time to slow the vehicle down
enough to avoid a collision with another
vehicle you are following. This can occur
when vehicles suddenly slow or stop
ahead, or enter your lane. Also see
“Alerting the Driver” in this section.
Complete attention is always required
while driving and you should be ready to
take action and apply the brakes. See
Defensive Driving 0201.
{Warning
ACC will not detect or brake for children,
pedestrians, animals, or other objects.
Do not use ACC when:
.On winding and hilly roads or when
the sensors are blocked by snow, ice,
or dirt. The system may not detect a
vehicle ahead. Keep the entire front of
the vehicle clean.
.Visibility is low, such as in fog, rain,
or snow conditions. ACC performance
is limited under these conditions.
(Continued)

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-14608671) - 2021 - CRC - 10/26/20
Driving and Operating 233
Warning (Continued)
.On slippery roads where fast changes
in tire traction can cause excessive
wheel slip.
J:Press to turn the system on or off. The
indicator turns white on the instrument
cluster when ACC is turned on.
RES+ : Press briefly to resume the previous
set speed or to increase vehicle speed if ACC
is already activated. To increase speed by
1 km/h (1 mph), briefly press RES+. To
increase speed to the next 5 km/h (5 mph)
mark on the speedometer, press and hold
RES+, then release. SET–
:Press briefly to set the speed and
activate ACC or to decrease vehicle speed if
ACC is already activated. To decrease speed
by 1 km/h (1 mph), briefly press SET−. To
decrease speed to the next 5 km/h (5 mph)
mark on the speedometer, press and hold
SET−, then release.
*: Press to disengage ACC without erasing
the selected set speed.
[: Press to select a following gap time
(or distance) setting for ACC of Far, Medium,
or Near.
Switching Between ACC and Regular Cruise
Control
To switch between ACC and regular cruise
control, press and hold
*. A Driver
Information Display (DIC) message displays.
See Vehicle Messages 0122.
ACC IndicatorRegular Cruise Control
Indicator When ACC is engaged, a green
]indicator
will be lit on the instrument cluster. When
the regular cruise control is engaged, a
green
Jindicator will be lit on the
instrument cluster.
When the vehicle is turned on, the cruise
control mode will be set to the last mode
used before the vehicle was turned off.
{Warning
Always check the cruise control indicator
on the instrument cluster to determine
which mode cruise control is in before
using the feature. If ACC is not active, the
vehicle will not automatically brake for
other vehicles, which could cause a crash
if the brakes are not applied manually.
You and others could be seriously injured
or killed.
Setting Adaptive Cruise Control
If
Jis on when not in use, it could get
pressed and go into cruise when not desired.
Keep
Joff when cruise is not being used.
Select the set speed desired for cruise. This
is the vehicle speed when no vehicle is
detected in its path.

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-14608671) - 2021 - CRC - 10/26/20
234 Driving and Operating
ACC will not set at a speed less than
25 km/h (15 mph), although it can be
resumed when driving at lower speeds. The
minimum allowable set speed is 25 km/h
(15 mph).
To set ACC:1. Press
J.
2. Get up to the desired speed.
3. Press and release SET–.
4. Remove foot from the accelerator.
After ACC is set, it may immediately apply
the brakes if a vehicle ahead is detected
closer than the selected following gap.
ACC can also be set while the vehicle is
stopped if ACC is on and the brake pedal is
applied.
The ACC indicator displays on the
instrument cluster and Head-Up Display
(HUD), if equipped. When ACC is active, the
indicator will be lit green. Be mindful of speed limits, surrounding
traffic speeds, and weather conditions when
selecting the set speed.
Resuming a Set Speed
If ACC is set at a desired speed and then the
brakes are applied, ACC is disengaged
without erasing the set speed from memory.
To begin using ACC again, press RES+ up
briefly.
.If the vehicle is moving more than 5 km/h
(3 mph), it returns to the previous set
speed.
.If the vehicle is stopped with the brake
pedal applied, press RES+ and release the
brake pedal. ACC will hold the vehicle
until RES+ or the accelerator pedal is
pressed.
A green ACC indicator and the set speed
display on the instrument cluster. The
vehicle ahead indicator may be flashing if a
vehicle ahead was present and moved. See
“Approaching and Following a Vehicle” later
in this section.
Once ACC has resumed, if there is no vehicle
ahead, if the vehicle ahead is beyond the
selected following gap, or if the vehicle has
exited a sharp curve, then the vehicle speed
will increase to the set speed. Increasing Speed While ACC is at a Set Speed
If ACC is already activated, do one of the
following:
.Use the accelerator to get to the higher
speed. Press SET–
. Release the control
and the accelerator pedal. The vehicle will
now cruise at the higher speed.
When the accelerator pedal is pressed,
ACC will not brake because it is
overridden. While overridden, the ACC
indicator will turn blue on the instrument
cluster and heads up display, if equipped.
.Press and hold RES+ until the desired set
speed appears on the display, then
release it.
.To increase vehicle speed in small
increments, briefly press RES+. For each
press, the vehicle goes 1 km/h (1 mph)
faster.
.To increase speed in larger increments,
hold RES+. While holding RES+, the vehicle
speed increases to the next 5 km/h
(5 mph) step, then continues to increase
by 5 km/h (5 mph) at a time.
The set speed can also be increased while
the vehicle is stopped.

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-14608671) - 2021 - CRC - 10/26/20
Driving and Operating 235
.If stopped with the brake applied, press
RES+ until the desired set speed is
displayed.
.If ACC is holding the vehicle at a stop and
there is another vehicle directly ahead,
pressing RES+ will increase the set speed.
Pressing RES+ when there is no longer a
vehicle ahead will cause ACC to resume.
When it is determined that there is no
vehicle ahead or the vehicle ahead is beyond
the selected following gap, then the vehicle
speed will increase to the set speed.
Reducing Speed While ACC is at a Set Speed
If ACC is already activated, do one of the
following:
.Use the brake to get to the desired lower
speed. Press SET– down and release the
accelerator pedal. The vehicle will now
cruise at the lower speed.
.Press and hold SET– until the desired
lower speed is reached, then release it.
.To decrease the vehicle speed in smaller
increments, briefly press SET−. For each
press, the vehicle goes about 1 km/h
(1 mph) slower.
.To decrease the vehicle speed in larger
increments, hold SET−. While holding
SET−, the vehicle speed decreases to the
next 5 km/h (5 mph) step, then continues
to decrease by 5 km/h (5 mph) at a time.
The set speed can also be decreased while
the vehicle is stopped.
.If stopped with the brake applied, press
or hold SET− until the desired set speed is
displayed.
Selecting the Follow Distance Gap
When a slower moving vehicle is detected
ahead within the selected following gap,
ACC will adjust the vehicle's speed and
attempt to maintain the follow distance gap
selected.
Press
[on the steering wheel to adjust
the following gap. Each press cycles the gap
button through three settings: Far, Medium,
or Near.
When pressed, the current gap setting
displays briefly on the instrument cluster
and HUD, if equipped. The gap setting will
be maintained until it is changed.
Since each gap setting corresponds to a
following time (Far, Medium, or Near), the
following distance will vary based on vehicle speed. The faster the vehicle speed, the
further back your vehicle will follow a
vehicle detected ahead. Consider traffic and
weather conditions when selecting the
following gap. The range of selectable gaps
may not be appropriate for all drivers and
driving conditions.
Changing the gap setting automatically
changes the alert timing sensitivity (Far,
Medium, or Near) for the Forward Collision
Alert (FCA) feature. See
Forward Collision
Alert (FCA) System 0245.
Alerting the Driver
With Head-Up Display
Without Head-Up Display

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-14608671) - 2021 - CRC - 10/26/20
236 Driving and Operating
If ACC is engaged, driver action may be
required when ACC cannot apply sufficient
braking because of approaching a vehicle
too rapidly.
When this condition occurs, the collision
alert symbol will flash on the windshield.
Either eight beeps will sound from the front,
or both sides of the Safety Alert Seat will
pulse five times. See“Collision/Detection
Systems” underVehicle Personalization
0 123.
See Defensive Driving 0201.
Approaching and Following a Vehicle
The vehicle ahead indicator is in the
instrument cluster and HUD, if equipped.
The vehicle ahead indicator 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 the
vehicle in front at the selected follow gap.
The vehicle speed increases or decreases to
follow the vehicle in front of you, but will
not exceed the set speed. It may apply
limited braking, if necessary. When braking
is active, the brake lights 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
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.

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
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Driving and Operating 237
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
StabiliTrak/ESC system has activated or
been disabled.
.There is a fault in the system.
.The radar may falsely report a blockage
when driving in a desert or remote area
with no other vehicles or roadside objects.
.A DIC message may display to indicate
that ACC is temporarily unavailable.
The ACC indicator will turn white when ACC
is no longer active.
In some cases, when ACC is temporarily
unavailable, regular cruise control may be
used. See “Switching Between ACC and
Regular Cruise Control” in this section.
Always consider driving conditions before
using either cruise control system.
Notification to Resume ACC
ACC will maintain a follow 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 resumed, the vehicle
ahead indicator will flash as a reminder to
check traffic ahead before proceeding. In
addition, the left and right sides of the
Safety Alert Seat will pulse three times,
or three beeps will sound. See
“Alert Type”
and “Adaptive Cruise Go Notifier” in
“Collision/Detection Systems” underVehicle
Personalization 0123.
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
and the driver seat belt is unbuckled, the
ACC automatically applies the Electric
Parking Brake (EPB) to hold the vehicle. The
EPB status light will turn on. See Electric
Parking Brake 0224. To resume ACC and
release the EPB, press the accelerator pedal.
A DIC warning message may display
indicating to shift to P (Park) before exiting
the vehicle. See Vehicle Messages 0122.
{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.
(Continued)
Warning (Continued)
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.
ACC Override
If using the accelerator pedal while ACC is
active, the ACC indicator turns blue on the
instrument cluster and HUD, if equipped.
ACC will resume operation when the
accelerator pedal is not being pressed.
{Warning
The ACC will not automatically apply the
brakes if your foot is resting on the
accelerator pedal. You could crash into a
vehicle ahead of you.

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-14608671) - 2021 - CRC - 10/26/20
238 Driving and Operating
Curves in the Road
{Warning
On curves, ACC may not detect a vehicle
ahead in your lane. You could be startled
if the vehicle accelerates up to the set
speed, especially when following a vehicle
exiting or entering exit ramps. You could
lose control of the vehicle or crash. Do
not use ACC while driving on an entrance
or exit ramp. Always be ready to use the
brakes if necessary.
{Warning
On curves, ACC may respond to a vehicle
in another lane, or may not have time to
react to a vehicle in your lane. You could
crash into a vehicle ahead of you, or lose
control of your vehicle. Give extra
attention in curves and be ready to use
the brakes if necessary. Select an
appropriate speed while driving in curves.
ACC may operate differently in a sharp
curve. It may reduce the vehicle speed if the
curve is too sharp. ACC automatically slows the vehicle down while navigating the curve
and may increase speed out of the curve,
but will not exceed the set speed.
When following a vehicle and entering a
curve, ACC may not detect the vehicle ahead
and accelerate to the set speed. When this
happens, the vehicle ahead indicator will not
appear.
ACC may detect a vehicle that is not in your
lane and apply the brakes.ACC may occasionally provide an alert and/
or braking that is considered unnecessary.
It could respond to vehicles in different
lanes, signs, guardrails, and other stationary
objects when entering or exiting a curve.
This is normal operation. The vehicle does
not need service.
Other Vehicle Lane Changes
ACC will not detect a vehicle ahead until it
is completely in the lane. The brakes may
need to be manually applied.
Objects Not Directly in Front of Your Vehicle
The detection of objects in front of the
vehicle may not be possible if:
.The vehicle or object ahead is not within
your lane.
.The vehicle ahead is shifted, not centered,
or is shifted to one side of the lane.

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
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Driving and Operating 239
Driving in Narrow Lanes
Vehicles in adjacent traffic lanes or roadside
objects may be incorrectly detected when
located along the roadway.
Do Not Use ACC on Hills and When Towing a
Trailer
Do not use ACC when driving on steep hills
or when towing a trailer. ACC will not detect
a vehicle in the lane while driving on steep
hills. The driver will often need to take over
acceleration and braking on steep hills,
especially when towing a trailer. If the
brakes are applied, the ACC disengages.
Disengaging ACC
There are three ways to disengage ACC:
.Step lightly on the brake pedal.
.Press*.
.PressJ.Erasing Speed Memory
The cruise control set speed is erased from
memory if
Jis pressed or if the ignition is
turned off.
Weather Conditions Affecting ACC
System operation may be limited under
snow, heavy rain, or road spray conditions.
Accessory Installations and Vehicle
Modifications
Do not install or place any object around
the front camera windshield area that would
obstruct the front camera view.
Do not install objects on top of the vehicle
that overhang and obstruct the front
camera, such as a canoe, kayak, or other
items that can be transported on a roof rack
system. See Roof Rack System 088.
Do not modify the hood, headlamps, or fog
lamps, as this may limit the camera’s ability
to detect an object.
Cleaning the Sensing System
The camera sensor on the windshield behind
the rearview mirror and the radar sensors
on the front of the vehicle can become blocked by snow, ice, dirt, or mud. These
areas need to be cleaned for ACC to operate
properly.
For cleaning instructions, see
“Washing the
Vehicle” underExterior Care 0337.
System operation may also be limited under
snow, heavy rain, or road spray conditions.
Driver Assistance Systems
This vehicle may have features that work
together to help avoid crashes or reduce
crash damage while driving, backing, and
parking. Read this entire section before
using these systems.
{Warning
Do not rely on the Driver Assistance
Systems. These systems do not replace
the need for paying attention and driving
safely. You may not hear or feel alerts or
warnings provided by these systems.
Failure to use proper care when driving
may result in injury, death, or vehicle
damage. See Defensive Driving 0201.
(Continued)