2021 GMC ACADIA brake

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-14608671) - 2021 - CRC - 10/26/20
208 Driving and Operating
{Warning
Coasting downhill in N (Neutral) or with
the ignition off is dangerous. This can
cause overheating of the brakes and loss
of steering assist. Always have the engine
running and the vehicle in gear.
.Drive at speeds that keep the vehicle in
its own lane. Do not swing wide or cross
the center line.
.Be alert on top of hills; something could
be in your lane (e.g., stalled car, crash).
.Pay attention to special road signs
(e.g., falling rocks area, winding roads,
long grades, passing or no-passing zones)
and take appropriate action.
Winter Driving
Driving on Snow or Ice
Snow or ice between the tires and the road
creates less traction or grip, so drive
carefully. Wet ice can occur at about 0 °C
(32 °F) when freezing rain begins to fall.
Avoid driving on wet ice or in freezing rain
until roads can be treated.For Slippery Road Driving:
.Accelerate gently. Accelerating too quickly
causes the wheels to spin and makes the
surface under the tires slick.
.Turn on Traction Control. See
Traction
Control/Electronic Stability Control 0226.
.The Antilock Brake System (ABS) improves
vehicle stability during hard stops, but
the brakes should be applied sooner than
when on dry pavement. See Antilock
Brake System (ABS) 0224.
.Allow greater following distance and
watch for slippery spots. Icy patches can
occur on otherwise clear roads in shaded
areas. The surface of a curve or an
overpass can remain icy when the
surrounding roads are clear. Avoid sudden
steering maneuvers and braking while
on ice.
.Turn off cruise control.
.Select All-Wheel Drive (AWD) Mode for
vehicles equipped with AWD. Select
Snow/Ice Mode for FWD only vehicles.
See Driver Mode Control 0228 and
All-Wheel Drive 0224.
Blizzard Conditions
Stop the vehicle in a safe place and signal
for help. Stay with the vehicle unless there
is help nearby. If possible, use Roadside
Assistance. See Roadside Assistance Program
0 366. To get help and keep everyone in
the vehicle safe:
.Turn on the hazard warning flashers.
.Tie a red cloth to an outside mirror.
{Warning
Snow can trap engine exhaust under the
vehicle. This may cause exhaust gases to
get inside. Engine exhaust contains
carbon monoxide (CO), which cannot be
seen or smelled. It can cause
unconsciousness and even death.
If the vehicle is stuck in snow:
.Clear snow from the base of the
vehicle, especially any blocking the
exhaust pipe.
.Open a window about 5 cm (2 in) on
the vehicle side that is away from the
wind, to bring in fresh air.
.Fully open the air outlets on or under
the instrument panel.
(Continued)

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-14608671) - 2021 - CRC - 10/26/20
212 Driving and Operating
Certification/Tire Label
Label Example
A vehicle-specific Certification/Tire label
is attached to the center pillar (B-pillar).
The label may show the size of the
vehicle's original tires and the inflation
pressures needed to obtain the gross
weight capacity of the vehicle. The label
shows the gross weight capacity of the
vehicle. This is called the Gross Vehicle
Weight Rating (GVWR). The GVWR
includes the weight of the vehicle, all
occupants, fuel, and cargo.The Certification/Tire label may also
show the maximum weights for the
front and rear axles, called the Gross
Axle Weight Rating (GAWR). To find out
the actual loads on the front and rear
axles, weigh the vehicle at a weigh
station. Your dealer can help with this.
Be sure to spread the load equally on
both sides of the centerline.
Caution
Overloading the vehicle may cause
damage. Repairs would not be covered by
the vehicle warranty. Do not overload the
vehicle.
{Warning
Things inside the vehicle can strike
and injure people in a sudden stop or
turn, or in a crash.
.Put things in the cargo area of the
vehicle. In the cargo area, put
them as far forward as possible.
Try to spread the weight evenly.
(Continued)
Warning (Continued)
.Never stack heavier things, like
suitcases, inside the vehicle so
that some of them are above the
tops of the seats.
.Do not leave an unsecured child
restraint in the vehicle.
.Secure loose items in the vehicle.
.Do not leave a seat folded down
unless needed.
Starting and Operating
New Vehicle Break-In
Caution
The vehicle does not need an elaborate
break-in. But it will perform better in the
long run if you follow these guidelines:
.Do not drive at any one constant
speed, fast or slow, for the first
800 km (500 mi). Do not make
full-throttle starts. Avoid downshifting
to brake or slow the vehicle.
(Continued)

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-14608671) - 2021 - CRC - 10/26/20
Driving and Operating 213
Caution (Continued)
.Avoid making hard stops for the first
300 km (200 mi) or so. During this
time the new brake linings are not yet
broken in. Hard stops with new linings
can mean premature wear and earlier
replacement. Follow this breaking-in
guideline every time you get new
brake linings.
Following break-in, engine speed and load
can be gradually increased.
Ignition Positions
The vehicle has an electronic keyless ignition
with pushbutton start. The Remote Keyless Entry (RKE) transmitter
must be in the vehicle for the system to
operate. If the pushbutton start is not
working, the vehicle may be near a strong
radio antenna signal causing interference to
the Remote Keyless Entry (RKE) system. See
Remote Keyless Entry (RKE) System
Operation
07.
To shift out of P (Park), the vehicle must be
on and the brake pedal must be applied.
Stopping the Engine/LOCK/OFF (No Indicator
Lights) : When the vehicle is stopped, press
ENGINE START/STOP once to turn the
engine off.
If the vehicle is in P (Park), the ignition will
turn off, and Retained Accessory Power (RAP)
will remain active. See Retained Accessory
Power (RAP) 0217.
If the vehicle is in R (Reverse), D (Drive) or
L (Low), the vehicle will shift to P (Park), the
ignition will turn off, and Retained Accessory
Power (RAP) will remain active. If the vehicle
is in N (Neutral), the ignition will return to
ACC/ACCESSORY and display the message
SHIFT TO PARK in the Driver Information
Center (DIC). When the vehicle is shifted
into P (Park), the ignition will turn off. Do not turn the engine off when the vehicle
is moving. This will cause a loss of power
assist in the brake and steering systems and
disable the airbags.
If the vehicle must be shut off in an
emergency:
1. Brake using a firm and steady pressure. Do not pump the brakes repeatedly. This
may deplete power assist, requiring
increased brake pedal force.
2. Shift the vehicle to N (Neutral). This can be done while the vehicle is moving.
After shifting to N (Neutral), firmly apply
the brakes and steer the vehicle to a
safe location.
3. Come to a complete stop and shift to P (Park).
4. Set the parking brake. See Electric
Parking Brake 0224. And press ENGINE
START/STOP to turn the vehicle off.
{Warning
Turning off the vehicle while moving may
cause loss of power assist in the brake
and steering systems and disable the
airbags. While driving, only shut the
vehicle off in an emergency.

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-14608671) - 2021 - CRC - 10/26/20
214 Driving and Operating
If the vehicle cannot be pulled over, and
must be shut off while driving, press and
hold ENGINE START/STOP for longer than
two seconds, or press twice in five seconds.
ACC/ACCESSORY (Amber Indicator Light) :
This mode allows some electrical accessories
to be used when the engine is off.
With the ignition off, pressing the button
one time without the brake pedal applied
will place the ignition system in ACC/
ACCESSORY.
The ignition will switch from ACC/
ACCESSORY to off after five minutes to
prevent battery rundown.
ON/RUN/START (Green Indicator Light) :This
mode is for driving and starting. With the
ignition off, and the brake pedal applied,
pressing the button once will place the
ignition system in ON/RUN/START. Once
engine cranking begins, release the button.
Engine cranking will continue until the
engine starts. See Starting the Engine 0214.
The ignition will then remain in ON/RUN.
Service Mode
This power mode is available for service and
diagnostics, and to verify the proper
operation of the malfunction indicator lamp
as may be required for emission inspection purposes. With the vehicle off, and the
brake pedal not applied, pressing and
holding the button for more than
five seconds will place the vehicle in Service
Mode. The instruments and audio systems
will operate as they do in ON/RUN, but the
vehicle will not be able to be driven. The
engine will not start in Service Mode. Press
the button again to turn the vehicle off.
Starting the Engine
Shift the vehicle into P (Park) or N (Neutral).
To restart the engine when the vehicle is
already moving, use N (Neutral) only.
Caution
Do not try to shift to P (Park) if the
vehicle is moving. If you do, you could
damage the transmission. Shift to P (Park)
only when the vehicle is stopped.
Caution
If you add electrical parts or accessories,
you could change the way the engine
operates. Any resulting damage would
not be covered by the vehicle warranty.
See
Add-On Electrical Equipment 0266.
Starting Procedure
1. With the Keyless Access system, the RKE
transmitter must be in the vehicle. Press
ENGINE START/STOP with the brake pedal
applied. When the engine begins
cranking, let go of the button.
The idle speed will go down as the
engine gets warm. Do not race the
engine immediately after starting it.
If the RKE transmitter is not in the
vehicle, if there is interference, or if the
RKE battery is low, the Driver
Information Center (DIC) will display a
message.
Caution
Cranking the engine for long periods of
time, by trying to start the engine
immediately after cranking has ended,
can overheat and damage the cranking
motor, and drain the battery. Wait at
least 15 seconds between each try, to let
the cranking motor cool down.
2. If the engine does not start after five to 10 seconds, especially in very cold
weather (below −18 °C or 0 °F), it could
be flooded with too much gasoline. Try
pushing the accelerator pedal all the way

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-14608671) - 2021 - CRC - 10/26/20
Driving and Operating 215
to the floor and holding it there as you
press ENGINE START/STOP, for up to a
maximum of 15 seconds. Wait at least
15 seconds between each try, to allow
the cranking motor to cool down. When
the engine starts, let go of the button
and the accelerator. If the vehicle starts
briefly but then stops again, do the
same thing. This clears the extra gasoline
from the engine. Do not race the engine
immediately after starting it. Operate
the engine and transmission gently until
the oil warms up and lubricates all
moving parts.
Stop/Start System
The Stop/Start system will shut off the
engine to help conserve fuel. It has
components designed for the increased
number of starts.
{Warning
The automatic engine Stop/Start feature
causes the engine to shut off while the
vehicle is still on. Do not exit the vehicle
before shifting to P (Park). The vehicle
may restart and move unexpectedly.
Always shift to P (Park), and then turn
the ignition off before exiting the vehicle.Auto Engine Stop/Start
When the brakes are applied and the vehicle
is at a complete stop, the engine may turn
off. When stopped, the tachometer displays
AUTO STOP. See
Tachometer0102. When
the brake pedal is released or the
accelerator pedal is pressed, the engine will
restart.
To maintain vehicle performance, other
conditions may cause the engine to
automatically restart before the brake pedal
is released.
Auto Stops may not occur and/or auto
restarts may occur because:
.The climate control settings require the
engine to be running to cool or heat the
vehicle interior.
.The vehicle battery charge is low.
.The vehicle battery has recently been
disconnected.
.Minimum vehicle speed has not been
reached since the last Auto Stop
.The accelerator pedal is pressed.
.The engine or transmission is not at the
required operating temperature.
.The outside temperature is not in the
required operating range.
.The transmission is shifted out of
D (Drive) to any gear other than P (Park).
.Tow/Haul Mode or other driver modes
have been selected.
.The vehicle is on a steep hill or grade.
.The driver door has been opened or driver
seat belt has been unbuckled.
.The hood has been opened.
.The Auto Stop has reached the maximum
allowed time.
Auto Stop/Start Disable Switch
The automatic engine Stop/Start feature can
be disabled and enabled by pressing
h.
Auto Stop/Start is enabled each time you
start the vehicle.

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-14608671) - 2021 - CRC - 10/26/20
Driving and Operating 217
{Warning
Improper use of the heater cord or an
extension cord can damage the cord and
may result in overheating and fire.
.Plug the cord into a three-prong
electrical utility receptacle that is
protected by a ground fault detection
function. An ungrounded outlet could
cause an electric shock.
.Use a weatherproof, heavy-duty,
15 amp-rated extension cord if needed.
Failure to use the recommended
extension cord in good operating
condition, or using a damaged heater
or extension cord, could make it
overheat and cause a fire, property
damage, electric shock, and injury.
.Do not operate the vehicle with the
heater cord permanently attached to
the vehicle. Possible heater cord and
thermostat damage could occur.
.While in use, do not let the heater
cord touch vehicle parts or sharp
edges.
.Before starting the vehicle, unplug the
cord. Keep the cord away from any
moving parts.6. Before starting the engine, be sure to
unplug and store the cord.
7. Install the engine heater connector cover.
The length of time the heater should remain
plugged in depends on several factors. Ask a
dealer in the area where you will be parking
the vehicle for the best advice on this.
Retained Accessory Power (RAP)
When the ignition is turned from on to off,
the following features (if equipped) will
continue to function for up to 10 minutes,
or until the driver door is opened. These
features will also work when the ignition is
in RUN or ACC/ACCESSORY:
.Infotainment System
.Power Windows (during RAP this
functionality will be lost when any door
is opened)
.Sunroof (during RAP this functionality will
be lost when any door is opened)
.Auxiliary Power Outlet
.Audio System
.OnStar System
Shifting Into Park
{Warning
It can be dangerous to get out of the
vehicle if the vehicle is not in P (Park)
with the parking brake set. The vehicle
can roll. If you have left the engine
running, the vehicle can move suddenly.
You or others could be injured. To be
sure the vehicle will not move, even
when you are on fairly level ground, use
the steps that follow. If you are pulling a
trailer, see Driving Characteristics and
Towing Tips 0256.
To shift into P (Park): 1. Hold the brake pedal down and set the parking brake. See Electric Parking Brake
0 224.
2. Press the P (Park) switch on the center console.
3. Press ENGINE START/STOP to turn the engine off.
If the vehicle is shifted into P (Park) on a
hill, the electric parking brake (EPB) may
apply automatically. The driver may not be

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-14608671) - 2021 - CRC - 10/26/20
218 Driving and Operating
able to release the EPB using the EPB
switch. It should automatically release when
the vehicle is shifted out of P (Park).
Leaving the Vehicle with the Engine
Running
{Warning
It can be dangerous to leave the vehicle
with the engine running. It could
overheat and catch fire.
It is dangerous to get out of the vehicle
if the vehicle is not in P (Park) with the
parking brake set. The vehicle can roll.
Do not leave the vehicle when the engine
is running. If you have left the engine
running, the vehicle can move suddenly.
You or others could be injured. To be
sure the vehicle will not move, even
when you are on fairly level ground,
always set the parking brake and shift
the vehicle to P (Park). SeeShifting Into
Park 0217. If you are towing a trailer,
see Driving Characteristics and Towing
Tips 0256. If you have to leave the vehicle with the
engine running, the vehicle must be in
P (Park) with the parking brake set.
Confirm that the vehicle is in P (Park).
Torque Lock
Torque lock is when the weight of the
vehicle puts too much force on the parking
pawl in the transmission. This happens when
parking on a hill and shifting the
transmission into P (Park) is not done
properly and then it is difficult to shift out
of P (Park). To prevent torque lock, set the
parking brake and then shift into P (Park). To
find out how, see
“Shifting Into Park” listed
previously.
On certain steep grades, the transmission
will automatically set the parking brake to
prevent torque lock.
If torque lock does occur, the vehicle may
need to be pushed uphill by another vehicle
to relieve the parking pawl pressure, so you
can shift out of P (Park).
Shifting out of Park
This vehicle is equipped with an electronic
transmission. If the vehicle has an
uncharged battery or a battery with low
voltage, try charging or jump starting the
battery. See Jump Starting - North America
0 332.
To shift out of P (Park): 1. Ensure the engine is running.
2. Apply the brake pedal.
3. Press or pull the desired shift switch on the center stack.
The P indicator will turn white and the gear
indicator will turn red when the vehicle is
no longer in P (Park).
If the vehicle cannot shift from P (Park), a
Driver Information Center (DIC) message will
be displayed. Check that the ignitionis on,
the engine is running, and the brake pedal
is applied when you are attempting to shift
out of P (Park). If all of these are met but
the vehicle will not shift out of P (Park), see
your dealer for service.

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-14608671) - 2021 - CRC - 10/26/20
220 Driving and Operating
Warning (Continued)
If unusual fumes are detected or if it is
suspected that exhaust is coming into the
vehicle:
.Drive it only with the windows
completely down.
.Have the vehicle repaired immediately.
Never park the vehicle with the engine
running in an enclosed area such as a
garage or a building that has no fresh air
ventilation.
Running the Vehicle While Parked
It is better not to park with the engine
running.
If the vehicle is left with the engine running,
follow the proper steps to be sure the
vehicle will not move. See Shifting Into Park
0 217 and
Engine Exhaust 0219.
If parking on a hill and pulling a trailer, see
Driving Characteristics and Towing Tips
0 256.
Automatic Transmission
The shift switches are on the center stack.
The selected gear position will illuminate red
on the shift switch, while all others will be
displayed in white. If the shift is not
immediate, as in very cold conditions, the
indicator on the shift switch may flash until
it is fully engaged.
The transmission does not operate when the
vehicle is off.
If the vehicle is in ACC/ACCESSORY, the
transmission can be shifted into P (Park). If ENGINE START/STOP is pressed twice while
at a relatively high speed, the engine will
turn off and the transmission will
automatically shift to N (Neutral). Once the
vehicle is stopped, P (Park) can be selected.
P :
This position locks the drive wheels. Use
P (Park) when starting the vehicle to ensure
the vehicle does not move.
{Warning
It is dangerous to get out of the vehicle
if the transmission is not in P (Park) with
the parking brake set. The vehicle
can roll.
Do not leave the vehicle when the engine
is running. If the engine has been left
running, the vehicle can move suddenly.
You or others could be injured. To be
sure the vehicle will not move, even
when on fairly level ground, always set
the parking brake and place the
transmission into P (Park). See Shifting
Into Park 0217 and
Driving Characteristics and Towing Tips
0 256.