wheel GMC ACADIA 2021 Workshop Manual

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-14608671) - 2021 - CRC - 10/26/20
Driving and Operating 221
This vehicle is equipped with an
electronically controlled transmission. The
R (Reverse) and D (Drive) shift switches are
designed to prevent inadvertent shifting out
of P (Park) unless the ignition is on, and the
brake pedal is applied.
When the vehicle is stopped, press ENGINE
START/STOP to turn off the vehicle. The
transmission will shift to P (Park)
automatically.
The vehicle will not shift into P (Park) if it is
moving too fast. Stop the vehicle and shift
into P (Park).
To shift in and out of P (Park), seeShifting
Into Park 0217 and
Shifting out of Park 0218.
R : Use this gear to back up.
If the vehicle is shifted from either
R (Reverse) to D (Drive), or D (Drive) to
R (Reverse) while the speed is too high, the
vehicle will shift to N (Neutral). Reduce the
vehicle speed and try the shift again.
To shift into R (Reverse): 1. Bring the vehicle to a complete stop.
2. Pull the R (Reverse) switch on the center stack. To shift out of R (Reverse):
1. Bring the vehicle to a complete stop.
2. Shift to the desired gear.
At low vehicle speeds, R (Reverse) can be
used to rock the vehicle back and forth to
get out of snow, ice, or sand without
damaging the transmission. See If the
Vehicle Is Stuck 0209.
N : In this position, the engine does not
connect with the wheels. To restart the
engine when the vehicle is already moving,
use N (Neutral) only.
{Warning
Shifting into a drive gear while the
engine is running at high speed is
dangerous. Unless your foot is firmly on
the brake pedal, the vehicle could move
very rapidly. You could lose control and
hit people or objects. Do not shift into a
drive gear while the engine is running at
high speed.
Caution
Shifting out of P (Park) or N (Neutral) with
the engine running at high speed may
damage the transmission. The repairs
would not be covered by the vehicle
warranty. Be sure the engine is not
running at high speed when shifting the
vehicle.
Caution
The vehicle is not designed to stay in
N (Neutral) for extended periods of time.
It will automatically shift into P (Park).
To shift into N (Neutral), press the
N (Neutral) switch until the N indicator
displays.
To shift out of N (Neutral): 1. Bring the vehicle to a complete stop.
2. Shift to the desired gear.
Car Wash Mode
This vehicle includes a Car Wash Mode that
allows the vehicle to remain in N (Neutral)
for use in automatic car washes.

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-14608671) - 2021 - CRC - 10/26/20
224 Driving and Operating
time allowed, the lower gear range shift will
not be completed. Slow the vehicle, then
press the−(Minus) button to the desired
lower gear range.
While using ERS, cruise control can be used.
Tow/Haul Mode
See Driver Mode Control 0228.
Drive Systems
All-Wheel Drive
Vehicles with this feature can operate in
AWD Mode. See Driver Mode Control 0228.
Brakes
Electric Brake Boost
Vehicles equipped with electric brake boost
have hydraulic brake circuits that are
electronically controlled when the brake
pedal is applied during normal operation.
The system performs routine tests and turns
off within a few minutes after the vehicle is
turned off. Noise may be heard during this
time. If the brake pedal is pressed during the tests or when the electric brake boost
system is off, a noticeable change in pedal
force and travel may be felt. This is normal.
Antilock Brake System (ABS)
The Antilock Brake System (ABS) helps
prevent a braking skid and maintain steering
while braking hard.
ABS performs a system check when the
vehicle is first driven. A momentary motor
or clicking noise may be heard while this
test is going on, and the brake pedal may
move slightly. This is normal.
If there is a problem with ABS, this warning
light stays on. See
Antilock Brake System
(ABS) Warning Light 0110.
ABS does not change the time needed to
get a foot on the brake pedal and does not
always decrease stopping distance. If you
get too close to the vehicle ahead, there will
not be enough time to apply the brakes if that vehicle suddenly slows or stops. Always
leave enough room ahead to stop, even
with ABS.
Using ABS
Do not pump the brakes. Just hold the brake
pedal down firmly. Hearing or feeling ABS
operate is normal.
Braking in Emergencies
ABS allows steering and braking at the same
time. In many emergencies, steering can
help even more than braking.
Electric Parking Brake

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-14608671) - 2021 - CRC - 10/26/20
Driving and Operating 225
The Electric Parking Brake (EPB) can always
be applied, even if the vehicle is off. In case
of insufficient electrical power, the EPB
cannot be applied or released. To prevent
draining the battery, avoid unnecessary
repeated cycles of the EPB.
The system has a red parking brake status
light and an amber service parking brake
warning light. SeeElectric Parking Brake
Light 0109 and
Service Electric Parking Brake Light (Uplevel
and Midlevel Cluster Only) 0109. There are
also parking brake-related Driver Information
Center (DIC) messages.
Before leaving the vehicle, check the red
parking brake status light to ensure that the
parking brake is applied.
EPB Apply
To apply the EPB:
1. Be sure the vehicle is at a complete stop.
2. Press the EPB switch momentarily.
The red parking brake status light will flash
and then stay on once the EPB is fully
applied. If the red parking brake status light
flashes continuously, then the EPB is only partially applied or there is a problem with
the EPB. A DIC message will display. Release
the EPB and try to apply it again. If the
light does not come on, or keeps flashing,
have the vehicle serviced. Do not drive the
vehicle if the red parking brake status light
is flashing. See your dealer.
If the amber service parking brake warning
light is on, press the EPB switch. Continue to
hold the switch until the red parking brake
status light remains on. If the amber service
parking brake warning light is on, see your
dealer.
If the EPB is applied while the vehicle is
moving, the vehicle will decelerate as long
as the switch is pressed. If the switch is
pressed until the vehicle comes to a stop,
the EPB will remain applied.
The vehicle may automatically apply the EPB
in some situations when the vehicle is not
moving. This is normal, and is done to
periodically check the correct operation of
the EPB system, or at the request of other
safety functions that utilize the EPB.
If the EPB fails to apply, block the rear
wheels to prevent vehicle movement.
EPB Release
To release the EPB:
1. Turn the ignition on or to ACC/ACCESSORY.
2. Apply and hold the brake pedal.
3. Press the EPB switch momentarily.
The EPB is released when the red parking
brake status light is off.
If the amber service parking brake warning
light is on, release the EPB by pressing and
holding the EPB switch. Continue to hold the
switch until the red parking brake status
light is off. If either light stays on after
release is attempted, see your dealer.
Caution
Driving with the parking brake on can
overheat the brake system and cause
premature wear or damage to brake
system parts. Make sure that the parking
brake is fully released and the brake
warning light is off before driving.
If you are towing a trailer and parking on a
hill, see Driving Characteristics and Towing
Tips 0256.

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-14608671) - 2021 - CRC - 10/26/20
226 Driving and Operating
Automatic EPB Release
The EPB will automatically release if the
vehicle is running, placed into gear, and an
attempt is made to drive away. Avoid rapid
acceleration when the EPB is applied, to
preserve parking brake lining life.
Brake Assist
Brake Assist detects rapid brake pedal
applications due to emergency braking
situations and provides additional braking to
activate the Antilock Brake System (ABS) if
the brake pedal is not pushed hard enough
to activate ABS normally. Minor noise, brake
pedal pulsation, and/or pedal movement
during this time may occur. Continue to
apply the brake pedal as the driving
situation dictates. Brake Assist disengages
when the brake pedal is released.
Hill Start Assist (HSA)
{Warning
Do not rely on the HSA feature. HSA does
not replace the need to pay attention
and drive safely. You may not hear or
feel alerts or warnings provided by this
system. Failure to use proper care when
driving may result in injury, death,
or vehicle damage. SeeDefensive Driving
0 201.
When the vehicle is stopped on a grade, Hill
Start Assist (HSA) prevents the vehicle from
rolling in an unintended direction during the
transition from brake pedal release to
accelerator pedal apply. The brakes release
when the accelerator pedal is applied. If the
accelerator pedal is not applied within a few
minutes, the Electric Parking Brake will
apply. The brakes may also release under
other conditions. Do not rely on HSA to hold
the vehicle.
HSA is available when the vehicle is facing
uphill in a forward gear, or when facing
downhill in R (Reverse). The vehicle must
come to a complete stop on a grade for HSA
to activate.
Ride Control Systems
Traction Control/Electronic
Stability Control
System Operation
The vehicle has a Traction Control System
(TCS) and StabiliTrak/Electronic Stability
Control (ESC), an electronic stability control
system. These systems help limit wheel spin
and assist the driver in maintaining control,
especially on slippery road conditions.
TCS activates if it senses that any of the
drive wheels are spinning or beginning to
lose traction. When this happens, TCS
applies the brakes to the spinning wheels
and reduces engine power to limit
wheel spin.
StabiliTrak/ESC activates when the vehicle
senses a difference between the intended
path and the direction the vehicle is actually
traveling. StabiliTrak/ESC selectively applies
braking pressure to any one of the vehicle
wheel brakes to assist the driver in keeping
the vehicle on the intended path.
If cruise control is being used and TCS or
StabiliTrak/ESC begins to limit wheel spin,
cruise control will disengage. Cruise control

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-14608671) - 2021 - CRC - 10/26/20
Driving and Operating 227
may be turned back on when road
conditions allow. TCS and StabiliTrak/ESC will
automatically turn on when cruise control
is set.
Both systems come on automatically when
the vehicle is started and begins to move.
The systems may be heard or felt while
they are operating or while performing
diagnostic checks. This is normal and does
not mean there is a problem with the
vehicle.
It is recommended to leave both systems on
for normal driving conditions, but it may be
necessary to turn TCS off if the vehicle gets
stuck in sand, mud, ice, or snow. SeeIf the
Vehicle Is Stuck 0209 and“Turning the
Systems Off and On” later in this section.
The indicator light for both systems is in the
instrument cluster. This light:
.Will flash when TCS is limiting wheel spin
.Will flash when StabiliTrak/ESC is
activated
.Will turn on and stay on when either
system is not working
.May flash when ABS is active
If either system fails to turn on or to
activate, a message may display in the
Driver Information Center (DIC), and
d
comes on and stays on to indicate that the
system is inactive and is not assisting the
driver in maintaining control. The vehicle is
safe to drive, but driving should be adjusted
accordingly.
If
dcomes on and stays on:
1. Stop the vehicle.
2. Turn the engine off and wait 15 seconds.
3. Start the engine.
4. Drive the vehicle.
If
dcomes on and stays on, the vehicle
may need more time to diagnose the
problem. If the condition persists, see your
dealer.
Turning the Systems Off and On
Caution
Do not repeatedly brake or accelerate
heavily when TCS is off. The vehicle
driveline could be damaged.
To turn off only TCS, press and release
g.
The Traction Off light
idisplays in the
instrument cluster and a DIC message may
display.
To turn TCS on again, press and release
g.
The Traction Off light
idisplayed in the
instrument cluster will turn off.

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-14608671) - 2021 - CRC - 10/26/20
228 Driving and Operating
If TCS is limiting wheel spin whengis
pressed, the system will not turn off until
the wheels stop spinning.
To turn off both TCS and StabiliTrak/ESC,
press and hold
guntil the Traction Off light
iand StabiliTrak/ESC OFF lightgcome on
and stay on in the instrument cluster. A DIC
message may display.
To turn TCS and StabiliTrak/ESC on again,
press and release
g. The Traction Off light
iand StabiliTrak/ESC OFF lightgin the
instrument cluster turn off.
StabiliTrak will automatically turn on if the
vehicle exceeds 56 km/h (35 mph). Traction
control will remain off.
Adding accessories can affect the vehicle
performance. See Accessories and
Modifications 0268.
Hill Descent Control (HDC)
If equipped, HDC can be used when driving
downhill. It sets and maintains vehicle speed
while descending a very steep incline in a
forward or reverse gear.
The HDC switch is on the center console. Press
5to enable or disable HDC. Vehicle
speed must be below 50 km/h (31 mph).
A blinking HDC light indicates the system is
actively applying the brakes to maintain
vehicle speed.
HDC can maintain vehicle speeds between
3–22 km/h (2–14 mph) on an incline greater
than or equal to a 10% grade.
When HDC is activated, the initial HDC
speed is set to the current driving speed.
It can be increased or decreased by pressing
the RES+ or SET– steering wheel controls or
by applying the accelerator or brake pedal.
This adjusted speed becomes the new set
speed. HDC will remain enabled between
22–60 km/h (14–37 mph); however vehicle
speed cannot be set or maintained in this
range. It will automatically disable if the
vehicle speed is above 80 km/h (50 mph) or
above 60 km/h (37 mph) for at least
30 seconds. Press
5again to re-enable HDC.
Driver Mode Control
If equipped, the Driver Mode Control has the
following Modes: Tour (FWD), Sport,
All-Wheel Drive (AWD), Snow/Ice, Tow/Haul,
and Off-Road. Rotate the Driver Mode
Control knob on the center console to make
a mode selection. Continue turning the knob
through the available modes. The selected
mode’s icon will light up on the knob and
there may be additional messages in the
Driver Information Center (DIC) and
indicators in the instrument cluster.
If the vehicle is in Tour (FWD) or AWD, it
will stay in that mode through future
ignition cycles. If the vehicle is in any other
mode, it will revert back to Tour (FWD)
when the vehicle is restarted.

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-14608671) - 2021 - CRC - 10/26/20
Driving and Operating 229
Driver Mode Control Knob (AWD)
Driver Mode Control Knob (FWD)
5orqTour (FWD) :Vehicle is in Tour
(FWD) Mode. Use this mode during normal
driving conditions. See Driving for Better Fuel
Economy 0200. Tour (FWD) Mode operates
in Front-Wheel Drive to improve fuel
economy.
8Sport : Sport Mode improves vehicle
handling and acceleration on dry pavement.
When active, Sport Mode modifies steering
efforts, transmission shifting, AWD torque,
and suspension tuning (when properly
equipped). For AWD vehicles, choosing Sport
Mode also engages AWD Mode.
The Performance Algorithm Liftfoot (PAL)
feature is enabled in Sport Mode. PAL allows
the transmission to hold the current gear
after a quick release of a heavily applied
accelerator pedal. This provides greater
engine braking and enhanced vehicle control.
When PAL is activated, there may be an
additional green gear symbol which appears
in the instrument cluster display. See Gear
Shifting Light 0110.
4AWD (AWD Only) : AWD Mode
provides drive torque to all four wheels.
Select AWD to improve traction and control
on slippery road surfaces, such as gravel,
sand, wet pavement, snow, and ice. When in AWD Mode, the AWD Mode indicator will be
on. The AWD Mode will stay selected until
the mode is changed.
AWD is active in AWD, Sport, Tow/Haul, and
Off-Road Modes.
Sport, Tow/Haul, and Off-Road Modes are
cancelled with each ignition cycle and will
return to Tour (FWD) Mode.
When using a compact spare tire on an
AWD vehicle, the system automatically
detects the compact spare and reduces AWD
performance to protect the system. To
restore full AWD operation and prevent
excessive wear on the system, replace the
compact spare with a full-size tire as soon as
possible. See
Compact Spare Tire 0331.
6Snow/Ice (FWD Only) : Snow/Ice Mode
improves vehicle acceleration on snow and
ice covered roads.
_Tow/Haul : This feature can assist
when towing or hauling a heavy load. Use
this mode to assist in maintaining desired
vehicle speeds when driving on downhill
grades by using the engine and
transmission. For AWD vehicles, choosing
Tow/Haul Mode also engages AWD mode.
See Driving Characteristics and Towing Tips
0 256.

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 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
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