
GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13687875) - 2020 - CRC - 10/28/19
Driving and Operating 191
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. SeeRemote Keyless Entry
(RKE) System Operation 08.
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) 0196.
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 0207.
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.
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.

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13687875) - 2020 - CRC - 10/28/19
192 Driving and Operating
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 0192. 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
0 258.
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
(Continued)

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13687875) - 2020 - CRC - 10/28/19
Driving and Operating 193
Caution (Continued)
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 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
Tachometer
0 121. 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

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13687875) - 2020 - CRC - 10/28/19
Driving and Operating 197
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 Tips0246.
To shift into P (Park): 1. Hold the brake pedal down and set the parking brake. See
Electric Parking Brake 0207.
2. Press P (Park).
3. Turn the ignition off.
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). See
Shifting Into Park 0197. If you
are towing a trailer, see Driving
Characteristics and Towing Tips
0 246. 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.

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13687875) - 2020 - CRC - 10/28/19
198 Driving and Operating
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. SeeJump Starting - North
America 0335.
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.
4. The P indicator will turn white and the gear indicator will turn
red when the vehicle is no
longer in P (Park). Manual Park Release
{Warning
The transmission will be placed in
N (Neutral) when the manual park
release is pulled. The vehicle can
roll and you or others could be
injured. Ensure the vehicle is on
level ground.
Caution
The manual park release is not
intended to be used for towing.
Damage may result from using
the manual park release in this
way. The repairs would not be
covered by the vehicle warranty.
Pulling the manual park release
while the vehicle is on, or turning
the ignition on while the manual
park release is pulled, will result in a
Service Transmission message
being displayed. To place the vehicle in N (Neutral)
using the manual park release:
1. Ensure the vehicle is on level ground and set the parking
brake. Release the brake
pedal.
2. Turn the vehicle off.
3. Use a flat-bladed tool to remove the interior trim panel
on the center console to the
right of the accelerator pedal.
4. Ensure more than one minute has elapsed since Step 2.
Apply the brake pedal.

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13687875) - 2020 - CRC - 10/28/19
Driving and Operating 199
5. Pull the manual park releaselever 90° to its latching
position.
6. With the brake pedal released, place the ignition in ACC/
ACCESSORY. Then apply the
brake pedal and release the
parking brake.
7. Ensure there are no loose objects in the area that could
bump the manual park release
lever.
To return the vehicle to P (Park)
using the manual park release: 1. Bring the vehicle to a complete stop.2. Rotate the manual park release90° back to its original position.
3. Apply the parking brake.
4. Confirm that the vehicle is in P (Park) by turning the ignition
on or placing the ignition in
ACC/ACCESSORY, then
ensure that the indicator
displays P.
5. Install the interior trim panel.
Parking over Things
That Burn
{Warning
Things that can burn could touch
hot exhaust parts under the
vehicle and ignite. Do not park
over papers, leaves, dry grass,
or other things that can burn.
Active Fuel Management
The vehicle’s engine may be
equipped with Active Fuel
Management, which allows the
engine to operate on either all of its
cylinders, or in reduced cylinder
operation, depending on the driving
conditions.
When less power is required, such
as cruising at a constant vehicle
speed, the system will operate in
reduced operation mode, allowing
the vehicle to achieve better fuel
economy. When greater power
demands are required, such as
accelerating from a stop, passing,

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13687875) - 2020 - CRC - 10/28/19
202 Driving and Operating
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
(Continued)
Warning (Continued)
transmission into P (Park). See
Shifting Into Park0197 and
Driving Characteristics and
Towing Tips 0246.
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), see
Shifting Into Park 0197 and
Shifting out of Park 0198.
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 0185.
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.

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13687875) - 2020 - CRC - 10/28/19
Driving and Operating 203
{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.
Car Wash Mode is not to be used
for vehicle towing. If the vehicle
needs to be towed, see Towing the
Vehicle 0338
Caution
The vehicle is not designed to
stay in N (Neutral) for extended
periods of time. It will
automatically shift into P (Park) if
left in Car Wash Mode.
Car Wash Mode (Engine Off –
Driver in Vehicle)
To place the vehicle in N (Neutral)
with the engine off and the vehicle
occupied:
1. Drive to the entrance of the car wash.
2. Apply the brake pedal.
3. Shift to N (Neutral).
4. Turn off the engine and release the brake pedal.
5. The indicator should continue to show N. If it does not, start
the engine and repeat
Steps 2–4.
6. The vehicle is now ready for the car wash.