Page 297 of 478

Black plate (25,1)GMC Acadia/Acadia Denali Owner Manual - 2011
Driving and Operating 9-25
{WARNING
It can be dangerous to get out
of the vehicle if the automatic
transmission 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 unless
you have to. 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).
Follow the proper steps to be
sure the vehicle will not move.
See Shifting Into Park on
page 9‑21.
If parking on a hill and pulling a
trailer, see Driving Characteristics
and Towing Tips on page 9‑47.
Automatic
Transmission
The automatic transmission has a
shift lever located on the console
between the seats.
P (Park): This position locks the
front wheels. It is the best position
to use 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.
Do not leave the vehicle when
the engine is running unless
you have to. 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). See Shifting Into Park
on page 9‑21. If you are pulling a
trailer, see Driving Characteristics
and Towing Tips on page 9‑47.
Make sure the shift lever is
fully in P (Park) before starting
the engine. The vehicle has
an automatic transmission
shift lock control system.
Page 298 of 478

Black plate (26,1)GMC Acadia/Acadia Denali Owner Manual - 2011
9-26 Driving and Operating
You must fully apply the regular
brake first and then press the shift
lever button before shifting from
P (Park) when the ignition key is
in ON/RUN. 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. SeeShifting Out
of Park on page 9‑23.
R (Reverse): Use this gear to
back up.
Notice: 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 on page 9‑11. N (Neutral):
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.
Notice: 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 (Drive):
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.
Notice: If the vehicle seems to
accelerate slowly or not shift
gears when you go faster, and
you continue to drive the vehicle
that way, you could damage the
transmission. Have the vehicle
serviced right away. You can
drive in L (Low) when you are
driving less than 56 km/h (35 mph)
and D (Drive) for higher speeds
until then.
If the vehicle is stopped on
a hill, with your foot off the brake
pedal, the vehicle may roll.
Page 299 of 478

Black plate (27,1)GMC Acadia/Acadia Denali Owner Manual - 2011
Driving and Operating 9-27
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 (Low):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.
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 down hill or towing a trailer.
The vehicle has an electronic
shift position indicator within the
instrument panel cluster. When
using the ERS Mode a number will
display next to the L, indicating the
current gear that has been selected. To use this feature:
1. Move the shift lever to L (Low).
2. Press the plus/minus button
located 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) (With DIC
Buttons) on page 5‑25 orDriver
Information Center (DIC) (Without
DIC Buttons) on page 5‑30 for more
information. 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).
While in L (Low), 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
the
−(Minus) button 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 and Tow/Haul mode.
While using the ERS, cruise control
and the tow/haul mode can be used.
See Tow/Haul Mode following.
Page 300 of 478

Black plate (28,1)GMC Acadia/Acadia Denali Owner Manual - 2011
9-28 Driving and Operating
Tow/Haul Mode
_
(Tow/Haul):The vehicle may
have a Tow/Haul mode.
The button is located on the
instrument panel under the climate
controls.
Push the button to activate the
system. Push it again to deactivate
the system. You can use this feature
to assist when towing or hauling a
heavy load.
When Tow/Haul is activated the
Tow/Haul symbol will come on
the instrument panel cluster.
See “Tow/Haul Mode” underDriving
Characteristics and Towing Tips on
page 9‑47 for more information.
Automatic Engine Grade
Braking
Automatic Engine Grade Braking
assists when driving on a downhill
grade. It maintains vehicle speed
by automatically implementing
a shift schedule that uses the
engine and the transmission to
slow the vehicle. The system will
automatically command downshifts
to reduce vehicle speed, until the
brake pedal is no longer being
pressed.
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 on
page 9‑25.
Drive Systems
All-Wheel Drive
Vehicles with this feature always
send engine power to all four
wheels. It is fully automatic, and
adjusts itself as needed for road
conditions.
When using a compact spare
tire on an AWD vehicle, the
system automatically detects the
compact spare and disables AWD.
To restore 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 on page 10‑82 for more
information.
Page 301 of 478

Black plate (29,1)GMC Acadia/Acadia Denali Owner Manual - 2011
Driving and Operating 9-29
Brakes
Antilock Brake
System (ABS)
This vehicle has the Antilock
Brake System (ABS), an advanced
electronic braking system that helps
prevent a braking skid.
When the engine is started and the
vehicle begins to drive away, ABS
checks itself. A momentary motor or
clicking noise might be heard while
this test is going on, and it might
even be noticed that the brake
pedal moves a little. This is normal.
If there is a problem with ABS, this
warning light stays on. SeeAntilock
Brake System (ABS) Warning Light
on page 5‑21. 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 that 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
the driver 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 might hear the ABS
pump or motor operating and feel
the brake pedal pulsate, but this is
normal.
Braking in Emergencies
ABS allows the driver to steer and
brake at the same time. In many
emergencies, steering can help
more than even the very best
braking.
Page 302 of 478

Black plate (30,1)GMC Acadia/Acadia Denali Owner Manual - 2011
9-30 Driving and Operating
Parking Brake
To set the parking brake, hold the
regular brake pedal down, then
push the parking brake pedal down.
If the ignition is on, the brake
system warning light will come on.
SeeBrake System Warning Light on
page 5‑20. Notice:
Driving with the parking
brake on can overheat the brake
system and cause premature
wear or damage to brake system
parts. Make sure that the parking
brake is fully released and the
brake warning light is off before
driving.
To release the parking brake, hold
the regular brake pedal down, then
push down momentarily on the
parking brake pedal until you feel
the pedal release. Slowly pull your
foot up off the park brake pedal.
If the parking brake is not released
when you begin to drive, the brake
system warning light will be on and
a chime will sound warning you that
the parking brake is still on.
If you are towing a trailer and
are parking on a hill, see Driving
Characteristics and Towing Tips on
page 9‑47.
Brake Assist
This vehicle has a brake assist
feature designed to assist the
driver in stopping or decreasing
vehicle speed in emergency
driving conditions. This feature
uses the stability system hydraulic
brake control module to supplement
the power brake system under
conditions where the driver has
quickly and forcefully applied the
brake pedal in an attempt to quickly
stop or slow down the vehicle.
The stability system hydraulic brake
control module increases brake
pressure at each corner of the
vehicle until the ABS activates.
Minor brake pedal pulsation or
pedal movement during this time
is normal and the driver should
continue to apply the brake pedal
as the driving situation dictates.
The brake assist feature will
automatically disengage when
the brake pedal is released or
brake pedal pressure is quickly
decreased.
Page 303 of 478

Black plate (31,1)GMC Acadia/Acadia Denali Owner Manual - 2011
Driving and Operating 9-31
Ride Control Systems
StabiliTrak®System
The vehicle has the StabiliTrak
system which combines antilock
brake, traction and stability control
systems and helps the driver
maintain directional control of the
vehicle in most driving conditions.
When you first start the vehicle
and begin to drive away, the
system performs several diagnostic
checks to ensure there are no
problems. The system may be
heard or felt while it is working.
This is normal and does not
mean there is a problem with the
vehicle. The system should initialize
before the vehicle reaches 32 km/h
(20 mph). In some cases, it may
take approximately 3.2 km (2 miles)
of driving before the system
initializes.
If the system fails to turn on or
activate, one of the following
messages will be displayed on theDriver Information Center (DIC):
SERVICE TRACTION CONTROL,
SERVICE STABILITRAK, the
StabiliTrak light will come on
and stay and four chimes are
heard. If these conditions are
observed, turn the vehicle off, wait
15 seconds, and then turn it back
on again to reset the system. If any
of these messages still appear on
the Driver Information Center (DIC),
the vehicle should be taken in for
service. For more information on
the DIC messages, see
Driver
Information Center (DIC) (With DIC
Buttons) on page 5‑25 orDriver
Information Center (DIC) (Without
DIC Buttons) on page 5‑30.
The StabiliTrak light will flash on the
instrument panel cluster when the
system is both on and activated. The system may be heard or felt
while it is working; this is normal.
The traction control button is located
on the instrument panel.
The traction control part of
StabiliTrak can be turned off by
pressing and releasing the traction
control button.
Traction control can be turned
on by pressing and releasing the
traction control button and the
appropriate TRACTION CONTROL
ON message will be displayed, if not
automatically shut off for any other
reason.
Page 304 of 478

Black plate (32,1)GMC Acadia/Acadia Denali Owner Manual - 2011
9-32 Driving and Operating
When the traction control system
is turned off, the appropriate
TRACTION CONTROL OFF
message will be displayed on
the DIC. The vehicle will still
have brake-traction control when
traction control is off, but will not
be able to use the engine speed
management system. See“Traction
Control Operation” following for
more information.
When the traction control system
has been turned off, system noises
may be heard and felt as a result of
the brake-traction control working.
It is recommended to leave the
system on for normal driving
conditions, but it may be necessary
to turn the system off if the vehicle
is stuck in sand, mud, ice or snow,
and you want to “rock”the vehicle
to attempt to free it. It may also be
necessary to turn off the system
when driving in extreme off-road
conditions where high wheel spin
is required. See If the Vehicle is
Stuck on page 9‑11.Traction Control Operation
The traction control system is part
of the StabiliTrak system. Traction
control limits wheel spin by reducing
engine power to the wheels (engine
speed management) and by
applying the brakes as necessary.
The traction control system is
enabled automatically when the
vehicle is started. It will activate
and the StabiliTrak light will flash
if it senses that any of the wheels
are spinning or beginning to lose
traction while driving. If traction
control is turned off, only the
brake-traction control portion
of traction control will work.
The engine speed management
will be disabled. In this mode,
engine power is not reduced
automatically and the driven
wheels can spin more freely.
This can cause the brake-traction
control to activate constantly. Notice:
If the wheel(s) of one axle
is allowed to spin excessively
while the StabiliTrak®, ABS, brake
warning lights, and any relevant
DIC messages are displayed, the
transfer case could be damaged.
The repairs would not be covered
by the vehicle warranty. Reduce
engine power and do not spin
the wheel(s) excessively while
these lights and messages are
displayed.
The traction control system may
activate on dry or rough roads
or under conditions such as
heavy acceleration while turning or
abrupt upshifts/downshifts of the
transmission. When this happens,
a reduction in acceleration may be
noticed, or a noise or vibration may
be heard. This is normal.