Page 225 of 423

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349114) - 2018 - crc - 9/21/17
224 Driving and Operating
Caution (Continued)
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 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
{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.
If equipped with the 2.5L L4 engine,
the vehicle has a fuel saving stop/
start system to shut off the engine to
help conserve fuel.
Auto 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
0 131. When the brake pedal is
released or the accelerator pedal is
pushed, the engine will restart.
Auto Stop may be deactivated if:
. A minimum vehicle speed is not
reached.
. The engine or transmission is
not at the required operating
temperature.
. The outside temperature is not
in the required operating range,
typically between −10 °C (14 °F)
and 50 °C (122 °F).
. The shift lever is in any gear
other than D (Drive).
. The battery charge is low.
. The interior comfort level has not
reached the required level for
the climate control system or
defog settings.
. The Auto Stop time is greater
than two minutes.
Page 226 of 423

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349114) - 2018 - crc - 9/21/17
Driving and Operating 225
Engine Heater
The engine heater can provide
easier starting and better fuel
economy during engine warm-up in
cold weather conditions at or below
0 °F (−18 °C). Vehicles with an
engine heater should be plugged in
at least four hours before starting.
Some models may have an internal
thermostat in the cord which will
prevent engine heater operation at
temperatures above 0 °F (−18 °C).
{Warning
Do not plug in the engine block
heater while the vehicle is parked
in a garage or under a carport.
Property damage or personal
injury may result. Always park the
vehicle in a clear open area away
from buildings or structures.
To Use the Engine Heater
1. Turn off the engine.
2. Open the hood and unwrap theelectrical cord. The bundled
cord is on the driver side of the
engine compartment, in front of
the battery. See Engine
Compartment Overview 0283.
Check the heater cord for
damage. If it is damaged, do
not use it. See your dealer for
a replacement. Inspect the
cord for damage yearly.
3. Plug the cord into a normal, grounded 110-volt AC outlet.
{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
(Continued)
Page 227 of 423

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349114) - 2018 - crc - 9/21/17
226 Driving and Operating
Warning (Continued)
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. Never
close the hood on the
heater cord.
. Before starting the vehicle,
unplug the cord, reattach
the cover to the plug, and
securely fasten the cord.
Keep the cord away from
any moving parts.
4. Before starting the engine, be sure to unplug and store the
cord as it was before to keep it away from moving engine
parts. If you do not, it could be
damaged.
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)
Some vehicle accessories may be
used after the ignition is turned off.
The power windows and sunroof,
if equipped, will continue to work for
up to 10 minutes or until any door is
opened.
The infotainment system will
continue to work for 10 minutes,
until the driver door is opened,
or until the ignition is turned on or
placed in ACC/ACCESSORY.
Shifting Into Park
1. Hold the brake pedal down and set the parking brake. See
Electric Parking Brake 0233. 2. Move the shift lever into
P (Park) by holding in the
button on the shift lever and
pushing the shift lever all the
way toward the front of the
vehicle.
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 shift lever is not fully
in P (Park) with the parking brake
firmly 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, (Continued)
Page 228 of 423

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349114) - 2018 - crc - 9/21/17
Driving and Operating 227
Warning (Continued)
always set the parking brake and
move the shift lever to P (Park).
SeeShifting Into Park 0226.
If you are towing a trailer, see
Driving Characteristics and
Towing Tips 0270.
If you have to leave the vehicle with
the engine running, be sure the
vehicle is in P (Park) and the
parking brake is firmly set before
you leave it. After you have moved
the shift lever into P (Park), hold the
regular brake pedal down. Then,
see if you can move the shift lever
away from P (Park) without first
pressing the button.
If you can, it means that the shift
lever was not fully locked 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.
If torque lock does occur, your
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
The vehicle is equipped with an
electronic shift lock release system.
The shift lock release is designed to
prevent movement of the shift lever
out of P (Park), unless the ignition is
on or in ACC/ACCESSORY, and the
regular brake pedal is applied.
The shift lock release is always
functional except in the case of an
uncharged or low voltage (less than
9-volt) battery. 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 0351 for more information.
To shift out of P (Park):
1. Turn the ignition on.
2. Apply the brake pedal.
3. Press the shift lever button.
4. Move the shift lever to the desired position.
If you still are unable to shift out of
P (Park): 1. Fully release the shift lever button.
2. While holding down the brake pedal, press the shift lever
button again.
3. Move the shift lever to the desired position.
If you still cannot move the shift
lever from P (Park), see your dealer.
Page 229 of 423

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349114) - 2018 - crc - 9/21/17
228 Driving and Operating
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.
Extended Parking
It is best not to park with the vehicle
running. If the vehicle is left running,
be sure it will not move and there is
adequate ventilation.
SeeShifting Into Park 0226 and
Engine Exhaust 0228.
If the vehicle is left parked and
running with the RKE transmitter
outside the vehicle, it will turn off
after one hour.
If the vehicle is left parked and
running with the RKE transmitter
inside the vehicle, it will turn off after
two hours. The vehicle could turn off sooner if it
is parked on a hill, due to lack of
available fuel.
The timer will reset if the vehicle is
taken out of P (Park) while it is
running.
Engine Exhaust
{Warning
Engine exhaust contains carbon
monoxide (CO), which cannot be
seen or smelled. Exposure to CO
can cause unconsciousness and
even death.
Exhaust may enter the vehicle if:
. The vehicle idles in areas
with poor ventilation
(parking garages, tunnels,
deep snow that may block
underbody airflow or tail
pipes).
. The exhaust smells or
sounds strange or different.
. The exhaust system leaks
due to corrosion or damage.
. The vehicle exhaust system
has been modified,
damaged, or improperly
repaired.
(Continued)
Page 230 of 423

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349114) - 2018 - crc - 9/21/17
Driving and Operating 229
Warning (Continued)
.There are holes or openings
in the vehicle body from
damage or aftermarket
modifications that are not
completely sealed.
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 0226 and
Engine Exhaust 0228.
If parking on a hill and pulling a
trailer, see Driving Characteristics
and Towing Tips 0270.
Automatic
Transmission
P : This position locks the drive
wheels. Use P (Park) when starting
the engine because the vehicle
cannot move easily.
{Warning
It is dangerous to get out of the
vehicle if the shift lever is not fully
in P (Park) with the parking brake
firmly set. The vehicle can roll.
(Continued)
Page 231 of 423

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349114) - 2018 - crc - 9/21/17
230 Driving and Operating
Warning (Continued)
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
move the shift lever to P (Park).
SeeShifting Into Park 0226 and
Driving Characteristics and
Towing Tips 0270.
Make sure the shift lever is fully in
P (Park) before starting the engine.
The vehicle has an automatic
transmission shift lock control
system. With the ignition on fully
apply the regular brake, then press
the button on the back of the shift
lever before shifting from P (Park).
If you cannot shift out of P (Park),
ease pressure on the shift lever,
then push the shift lever all the way
into P (Park) as you maintain brake
application. Then press the shift lever button and move the shift lever
into another gear. See
Shifting out
of Park 0227.
R : Use this gear to back up.
Caution
Shifting to R (Reverse) while the
vehicle is moving forward could
damage the transmission. The
repairs would not be covered by
the vehicle warranty. Shift to
R (Reverse) only after the vehicle
is stopped.
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 0217.
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.
Page 232 of 423

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349114) - 2018 - crc - 9/21/17
Driving and Operating 231
Caution
A transmission hot message may
display if the automatic
transmission fluid is too hot.
Driving under this condition can
damage the vehicle. Stop and idle
the engine to cool the automatic
transmission fluid. This message
clears when the transmission fluid
has cooled sufficiently.
D : This position is for normal
driving. If more power is needed for
passing, press the accelerator
pedal down.
Caution
If the vehicle does not shift gears,
the transmission could be
damaged. Have the vehicle
serviced right away.
If the vehicle is stopped on a hill,
with your foot off the brake pedal,
the vehicle may roll. This is normal
and is due to the torque converter designed to improve fuel economy
and performance. Use the brake to
hold the vehicle on a hill. Do not use
the accelerator pedal.
L :
This position gives you access
to gear ranges. This provides more
engine braking but lower fuel
economy than D (Drive). You can
use it on very steep hills, or in deep
snow or mud. See Manual Mode
0 231.
Operating Modes : The
transmission may operate in a lower
gear than normal to improve vehicle
performance. The engine speed
may be higher and there may be an
increase in noise during the
following conditions:
. When climbing a grade.
. When driving downhill.
. When driving in hot
temperatures, or at high altitude.
Manual Mode
Electronic Range Select
(ERS) Mode
ERS mode allows you to choose the
top-gear limit of the transmission
and the vehicle's speed while
driving downhill or towing a trailer.
The vehicle has an electronic shift
position indicator within the
instrument cluster. When using the
ERS mode a number will display
next to the L, indicating the highest
gear available for the range
selected.