transmission GMC ACADIA 2018 Owner's Guide

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.

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)

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.

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.

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349114) - 2018 - crc - 9/21/17
232 Driving and Operating
To use this feature:1. Move the shift lever to L (Manual Mode).
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 (Manual Mode), 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)
0 145 orDriver Information Center
(DIC) (Uplevel) 0148. 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 (Manual Mode) is
selected, a downshift to 4 (Fourth)
will be commanded. If in 5 (Fifth)
through 2 (Second) a single
downshift will occur.
While in L (Manual Mode), the
transmission will prevent shifting to
a lower gear range if the engine
speed is too high. You have a brief
period of time to slow the vehicle.
If vehicle speed is not reduced
within the time allowed, the lower
gear range shift will not be
completed. You must further slow
the vehicle, then press
−(Minus) to
the desired lower gear range.
Automatic Engine Grade Braking is
not available when the ERS is
active. It is available in D (Drive) for
both normal driving and Tow/Haul
Mode. While using the ERS, cruise
control and the Tow/Haul Mode can
be used. See Tow/Haul Mode 0232.
Tow/Haul Mode
See Driver Mode Control 0238.
Drive Systems
All-Wheel Drive
Vehicles with this feature can
operate in AWD Mode. See Driver
Mode Control 0238.

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349114) - 2018 - crc - 9/21/17
238 Driving and Operating
To turn TCS and StabiliTrak on
again, press and release
g. The
Traction Off light
iand StabiliTrak
OFF light
gin the instrument cluster
turn off.
Adding accessories can affect the
vehicle performance. See
Accessories and Modifications
0 281.
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, behind the transmission
shift lever.
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 and 22 km/h (2 and
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 and 60 km/h (14 and 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.
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-11349114) - 2018 - crc - 9/21/17
Driving and Operating 239
Driver Mode Control Knob
5orqTour (FWD) :Vehicle is
in Tour (FWD) Mode. Use this mode
during normal driving conditions.
See Driving for Better Fuel
Economy 027. 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.
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
0 350.6Snow/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
0 270.
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.

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349114) - 2018 - crc - 9/21/17
240 Driving and Operating
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 0229.
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 0209.
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 Traction Control System (TCS)
or StabiliTrak
®electronic stability
control system begins to limit wheel
spin while using cruise control, the
cruise control automatically disengages. See
Traction Control/
Electronic Stability Control 0236.
If a collision alert occurs when
cruise control is activated, cruise
control is disengaged. See Forward
Collision Alert (FCA) System 0256.
When road conditions allow the
cruise control to be safely used,
cruise control can be turned
back on.
Turning off the TCS or StabiliTrak
system will disengage the cruise
control.
If the brakes are applied, cruise
control disengages.

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349114) - 2018 - crc - 9/21/17
242 Driving and Operating
.To decrease the vehicle speed in
small increments, briefly press
SET−. For each press, the
vehicle goes about 1 km/h
(1 mph) slower.
The speedometer reading can be
displayed in either English or metric
units. See Instrument Cluster 0127.
The increment value used depends
on the units displayed.
Passing Another Vehicle While
Using Cruise Control
Use the accelerator pedal to
increase the vehicle speed. When
you take your foot off the pedal, the
vehicle will slow down to the
previous set cruise speed.
While pressing the accelerator pedal
or shortly following the release to
override cruise, briefly applying
SET− will result in cruise set to the
current vehicle speed.
Using Cruise Control on Hills
How well the cruise control will work
on hills depends upon the vehicle
speed, load, and the steepness of
the hills. When going up steep hills, you might have to step on the
accelerator pedal to maintain your
speed. While on a hill, the
transmission may downshift in order
to use engine braking to slow the
vehicle and maintain the set speed.
Also, you may have to brake or shift
to a lower gear to keep your speed
down. If the brake pedal is applied,
cruise control disengages.
Ending Cruise Control
There are four ways to end cruise
control:
.
Step lightly on the brake pedal.
. Press
*.
. Shift the transmission to
N (Neutral).
. Press
J.
Erasing Speed Memory
The cruise control set speed is
erased from memory if
Jis
pressed or if the ignition is
turned off.
Adaptive Cruise Control
If equipped with Adaptive Cruise
Control (ACC), it allows the driver to
select the cruise control set speed
and following gap. Read this entire
section before using this system.
The following gap is the following
time between your vehicle and a
vehicle detected directly ahead in
your path, moving in the same
direction. If no vehicle is detected in
your path, ACC works like regular
cruise control. ACC uses camera
and radar sensors. See Radio
Frequency Statement 0394.
If a vehicle is detected in your path,
ACC can apply acceleration or
limited, moderate braking to
maintain the selected following gap.
To disengage ACC, apply the brake.
If ACC is controlling your vehicle
speed when the Traction Control
System (TCS) or StabiliTrak
®
electronic stability control system
activates, the ACC may
automatically disengage. See
Traction Control/Electronic Stability
Control 0236. When road

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349114) - 2018 - crc - 9/21/17
Driving and Operating 271
.Do not tow a trailer during the
first 800 km (500 mi), to prevent
damage to the engine, axle or
other parts.
. Then, during the first 800 km
(500 mi) trailer towing, do not
drive over 80 km/h (50 mph) and
do not make starts at full throttle.
. The vehicle can tow in D (Drive)
but Manual Mode is
recommended. See Manual
Mode 0231. Use a lower gear if
the transmission shifts too often.
. Turn off Parking Assist and Rear
Cross Traffic Alert (RCTA) when
towing.
. Turn off Lane Keep Assist (LKA)
when towing.
. Do not use Adaptive Cruise
Control (ACC) when towing a
trailer.{Warning
When towing a trailer, exhaust
gases may collect at the rear of
the vehicle and enter if the
liftgate, trunk/hatch, or rear-most
window is open.
When towing a trailer:
. Do not drive with the
liftgate, trunk/hatch,
or rear-most window open.
. Fully open the air outlets on
or under the instrument
panel.
. Also adjust the climate
control system to a setting
that brings in only outside
air. See “Climate Control
Systems” in the Index.
For information about carbon
monoxide, see Engine Exhaust
0 228.
Towing a trailer requires a certain
amount of experience. The
combination you are driving is longer and not as responsive as the
vehicle itself. Get acquainted with
the handling and braking of the rig
before setting out for the open road.
Before starting, check all trailer hitch
parts and attachments, safety
chains, electrical connectors, lamps,
tires, and mirrors. If the trailer has
electric brakes, start the
combination moving and then apply
the trailer brake controller by hand
to be sure the brakes work.
During the trip, check occasionally
to be sure that the load is secure
and the lamps and any trailer
brakes still work.
Towing with a Stability Control
System
When towing, the sound of the
stability control system might be
heard. The system is reacting to the
vehicle movement caused by the
trailer, which mainly occurs during
cornering. This is normal when
towing heavier trailers.