
GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9803770) - 2017 - crc - 7/12/16
226 Driving and Operating
If the vehicle is not in P (Park), the
ignition will return to ACC/
ACCESSORY and display the
message SHIFT TO PARK in the
Driver Information Center (DIC).
SeeTransmission Messages 0156.
When the vehicle is shifted into
P (Park), the ignition system will
switch to 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, shift
to P (Park), and turn the
ignition to OFF. On vehicles
with an automatic transmission,
the shift lever must be in
P (Park) to turn the ignition
switch to the OFF position.
4. Set the parking brake. See Electric Parking Brake 0237.
{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.
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 0227. The
ignition will then remain in ON/RUN.
Service Only 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

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9803770) - 2017 - crc - 7/12/16
Driving and Operating 227
the vehicle in Service Only 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 Only Mode. Press the
button again to turn the vehicle off.
Starting the Engine
Move the shift lever to P (Park) or
N (Neutral). The engine will not start
in any other position. 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.
SeeAdd-On Electrical
Equipment 0280.
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. See
Key
and Lock Messages 0151.
Caution
Cranking the engine for long
periods of time, by returning the
ignition to the START position
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 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

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9803770) - 2017 - crc - 7/12/16
228 Driving and Operating
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
Exiting the vehicle without first
shifting into P (Park) may cause
the vehicle to move. You or others
may be injured. Because the
vehicle has the auto engine stop/
start feature, the vehicle's engine
might seem to be shut off;
however, once the brake pedal is
released, the engine will start up
again.
Shift to P (Park) and turn the
ignition to LOCK/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 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
0 127. 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.
Engine Heater
The engine coolant 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 coolant 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
coolant heater operation at
temperatures above 0 °F (−18 °C).

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9803770) - 2017 - crc - 7/12/16
Driving and Operating 229
To Use the Engine Coolant
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 0285.
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)
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.

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9803770) - 2017 - crc - 7/12/16
232 Driving and Operating
Extended Parking
It is better not to park with the
vehicle running. If the vehicle is left
while running, follow the proper
steps to be sure the vehicle will not
move and there is adequate
ventilation. SeeShifting Into Park
0 230 andEngine Exhaust 0232.
If the vehicle is left in P (Park) while
running and the Remote Keyless
Entry (RKE) transmitter is outside
the vehicle, the vehicle will turn off
after one hour.
If the vehicle is left in P (Park) while
running and the RKE transmitter is
inside, the vehicle will run for two
hours. At the end of the second
hour, the vehicle will turn off.
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)
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.

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9803770) - 2017 - crc - 7/12/16
234 Driving and Operating
press the shift lever button and
move the shift lever into another
gear. SeeShifting out of Park 0231.
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 0220.
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. Also, use N (Neutral) when the
vehicle is being towed.
{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. D :
This position is for normal
driving. It provides the best fuel
economy. If you need more power
for passing, and you are:
. Going less than 56 km/h
(35 mph), push the accelerator
pedal about halfway down.
. Going about 56 km/h (35 mph) or
more, push the accelerator all
the way 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

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9803770) - 2017 - crc - 7/12/16
Driving and Operating 235
economy than D (Drive). You can
use it on very steep hills, or in deep
snow or mud. SeeManual
Mode 0235.
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.
To use this feature:
1. Move the shift lever to L (Low).
2. Press + (Plus) or −(Minus) on
the shift lever to increase or
decrease the gear range
available.
When you shift from D (Drive) to
L (Low), the transmission will shift to
a pre-determined lower gear range.
The highest gear available for this
pre-determined range is displayed next to the L in the DIC. See
Driver
Information Center (DIC) (Base and
Midlevel) 0141 orDriver Information
Center (DIC) (Uplevel) 0144. The
number displayed in the DIC is the
highest gear that the transmission
will be allowed to operate in. This
means that all gears below that
number are available. For example,
when 4 (Fourth) is shown next to the
L, 1 (First) through 4 (Fourth) gears
are automatically shifted by the
vehicle. The transmission will not
shift into 5 (Fifth) until the + (Plus)
button is used or you shift back into
D (Drive).
If the transmission is in 6 (Sixth)
gear when L (Low) is selected, a
downshift to 4 (Fourth) will be
commanded. If in 5 (Fifth) through
2 (Second) a single downshift will
occur.

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9803770) - 2017 - crc - 7/12/16
Driving and Operating 237
If driving safely on a wet road and it
becomes necessary to slam on the
brakes and continue braking to
avoid a sudden obstacle, a
computer senses the wheels are
slowing down. If one of the wheels
is about to stop rolling, the computer
will separately work the brakes at
each wheel.
ABS can change the brake pressure
to each wheel, as required, faster
than any driver could. This can help
you steer around the obstacle while
braking hard.
As the brakes are applied, the
computer keeps receiving updates
on wheel speed and controls
braking pressure accordingly.
Remember: ABS does not change
the time needed to get a foot up to
the brake pedal or always decrease
stopping distance. If you get too
close to the vehicle in front of you,
there will not be enough time to
apply the brakes if that vehicle
suddenly slows or stops. Always
leave enough room up ahead to
stop, even with ABS.Using ABS
Do not pump the brakes. Just hold
the brake pedal down firmly and let
ABS work. You may hear the ABS
pump or motor operating and feel
the brake pedal pulsate. This is
normal.
Braking in Emergencies
ABS allows you to steer and brake
at the same time. In many
emergencies, steering can help
more than even the very best
braking.
Electric Parking Brake
The Electric Parking Brake (EPB)
switch is on the instrument panel, to
the left of the steering wheel. The
EPB can always be activated, even
if the ignition is off. To prevent
draining the battery, avoid repeated
cycles of the EPB when the engine
is not running.
The system has a red parking brake
status light and an amber parking
brake warning light. SeeElectric
Parking Brake Light 0135 and
Service Electric Parking Brake Light
0 135. There are also parking
brake-related Driver Information
Center (DIC) messages. See Brake
System Messages 0148. In case of
insufficient electrical power, the EPB
cannot be applied or released.
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 switch momentarily.