brakes GMC ACADIA 2011 User Guide

Black plate (9,1)GMC Acadia/Acadia Denali Owner Manual - 2011
Driving and Operating 9-9
WARNING (Continued)
that they would not work well.
You would then have poor braking
or even none going down a hill.
You could crash. Always have the
engine running and the vehicle in
gear when going downhill.
.Stay in your own lane. Do not
swing wide or cut across the
center of the road. Drive at
speeds that let you stay in
your own lane.
.Top of hills: Be
alert—something could
be in your lane (stalled car,
accident).
.Pay attention to special road
signs (falling rocks area, winding
roads, long grades, passing or
no-passing zones) and take
appropriate action.
Winter Driving
Driving on Snow or Ice
Drive carefully when there is
snow or ice between the tires
and the road, creating less traction
or grip. Wet ice can occur at about
0°C (32°F) when freezing rain
begins to fall, resulting in even less
traction. Avoid driving on wet ice or
in freezing rain until roads can be
treated with salt or sand.
Drive with caution, whatever the
condition. Accelerate gently so
traction is not lost. Accelerating
too quickly causes the wheels to
spin and makes the surface under
the tires slick, so there is even less
traction.
Try not to break the fragile traction.
If you accelerate too fast, the drive
wheels will spin and polish the
surface under the tires even more. The
Antilock Brake System (ABS)
on page 9‑29 improves vehicle
stability during hard stops on
slippery roads, but apply the brakes
sooner than when on dry pavement.
Allow greater following distance on
any slippery road and watch for
slippery spots. Icy patches can
occur on otherwise clear roads in
shaded areas. The surface of a
curve or an overpass can remain
icy when the surrounding roads
are clear. Avoid sudden steering
maneuvers and braking while
on ice.
Turn off cruise control on slippery
surfaces.

Black plate (18,1)GMC Acadia/Acadia Denali Owner Manual - 2011
9-18 Driving and Operating
Ignition Positions
The ignition switch has four different
positions.
In order to shift out of P (Park),
the ignition must be in ON/RUN or
ACC/ACCESSORY and the brake
pedal must be applied.Notice:
Using a tool to force the
key to turn in the ignition could
cause damage to the switch or
break the key. Use the correct
key, make sure it is all the way in,
and turn it only with your hand.
If the key cannot be turned by
hand, see your dealer.
((STOPPING THE ENGINE/
LOCK/OFF): When the vehicle is
stopped, turn the ignition switch to
LOCK/OFF to turn the engine off.
Retained Accessory Power (RAP)
will remain active. See Retained
Accessory Power (RAP) on
page 9‑21.
This position locks the ignition
and transmission. The key can
be removed in LOCK/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. 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 LOCK/OFF. On vehicles with
an automatic transmission, the
shift lever must be in P (Park) to
turn the ignition switch to the
LOCK/OFF position.
4. Set the parking brake. See Parking Brake on
page 9‑30.

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.

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.

Black plate (33,1)GMC Acadia/Acadia Denali Owner Manual - 2011
Driving and Operating 9-33
If cruise control is being used when
the system activates, the StabiliTrak
light will flash and cruise control will
automatically disengage. Cruise
control may be reengaged when
road conditions allow. SeeCruise
Control on page 9‑33.
StabiliTrak may also turn off
automatically if it determines that
a problem exists with the system.
If the problem does not clear itself
after restarting the vehicle, see your
dealer for service.Cruise Control
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).
When the brakes are applied, the
cruise control is disengaged.
{WARNING
Cruise control can be dangerous
where you cannot drive safely at
a steady speed. So, do not use
the 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.The cruise control buttons are
located on left side of the steering
wheel.
T(On/Off): Press to turn cruise
control on and off. The indicator
comes on when cruise control is on.
+ RES (Resume/Accelerate):
Press briefly to make the vehicle
resume to a previously set speed,
or press and hold to accelerate.
SET– :Press to set the speed and
activate cruise control or to make
the vehicle decelerate.

Black plate (34,1)GMC Acadia/Acadia Denali Owner Manual - 2011
9-34 Driving and Operating
[(Cancel):Press to disengage
cruise control without erasing the
set speed from memory.
Setting Cruise Control
If the cruise button is on when not in
use, it could get bumped and go into
cruise when not desired. Keep the
cruise control switch off when cruise
is not being used.
The cruise control light on the
instrument panel cluster comes on
after the cruise control has been
set to the desired speed.
1. Press the
Ibutton to turn the
cruise control system on.
2. Get up to the speed desired.
3. Press and release the SET– button located on the steering
wheel.
4. Take your foot off the accelerator. Resuming a Set Speed
If the cruise control is set at a
desired speed and then the brakes
are applied, the cruise control is
disengaged without erasing the
set speed from memory.
Once the vehicle speed is 40 km/h
(25 mph) or greater, press the
+RES button on the steering wheel.
The vehicle returns to the previously
set speed and stays there.
Increasing Speed While Using
Cruise Control
If the cruise control system is
already activated,
.Press and hold the +RES button
on the steering wheel until the
desired speed is reached, then
release it.
.To increase vehicle speed in
small increments, press the
+RES button briefly. Each time
this is done, the vehicle goes
about 1.6 km/h (1 mph) faster.Reducing Speed While Using
Cruise Control
If the cruise control system is
already activated,
.Press and hold the SET–
button
on the steering wheel until the
lower speed desired is reached,
then release it.
.To slow down in small amounts,
press the SET– button briefly.
Each time this is done, the
vehicle goes about 1.6 km/h
(1 mph) slower.
Passing Another Vehicle While
Using Cruise Control
Use the accelerator pedal to
increase vehicle speed. When
you take your foot off the pedal,
the vehicle will slow down to the
previously set cruise 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.

Black plate (35,1)GMC Acadia/Acadia Denali Owner Manual - 2011
Driving and Operating 9-35
When going up steep hills,
you might have to step on the
accelerator pedal to maintain
the vehicle speed. When going
downhill, you might have to brake
or shift to a lower gear to keep the
vehicle speed down. When the
brakes are applied the cruise
control is disengaged.
Ending Cruise Control
There are three ways to end cruise
control:
.Step lightly on the brake pedal.
.Press the[button.
.To turn off the cruise control,
press
Ton the steering wheel.
Erasing Speed Memory
The cruise control set speed is
erased from memory by pressing
the
Tbutton or if the ignition is
turned off.
Object Detection
Systems
Ultrasonic Parking Assist
For vehicles with the Ultrasonic
Rear Parking Assist (URPA) system,
it operates at speeds less than
8 km/h (5 mph), and assists the
driver with parking and avoiding
objects while in R (Reverse).
The sensors on the rear bumper are
used to detect the distance to an
object up to 2.5 m (8 ft) behind the
vehicle, and at least 25.4 cm (10 in)
off the ground.
{WARNING
The Ultrasonic Rear Parking
Assist (URPA) system does not
replace driver vision. It cannot
detect:
.Objects that are below the
bumper, underneath the
vehicle, or too close or far
from the vehicle.
.Children, pedestrians,
bicyclists, or pets.
If you do not use proper care
before and while backing, vehicle
damage, injury, or death could
occur. Even with URPA, always
check behind the vehicle before
backing up. While backing, be
sure to look for objects and check
the vehicle's mirrors.

Black plate (36,1)GMC Acadia/Acadia Denali Owner Manual - 2011
9-36 Driving and Operating
How the System Works
URPA comes on automatically
when the shift lever is moved into
R (Reverse). A single tone sounds
to indicate the system is working.
URPA operates only at speeds less
than 8 km/h (5 mph).
An obstacle is indicated by audible
beeps. The interval between the
beeps becomes shorter as the
vehicle gets closer to the obstacle.
When the distance is less than
30 cm (12 in) the beeps are
continuous.
To be detected, objects must be at
least 25.4 cm (10 in) off the ground
and below liftgate level. Objects
must also be within 2.5 m (8 ft) from
the rear bumper. This distance may
be less during warmer or humid
weather.
The system can be disabled through
the Driver Information Center (DIC).
See“Park Assist” underVehicle
Personalization (With DIC Buttons)
on page 5‑47 for more information.
When the System Does Not
Seem to Work Properly
If the URPA system does not
activate due to a temporary
condition, the message PARK
ASSIST OFF or PARK ASST
BLOCKED SEE OWNERS
MANUAL will be displayed
on the DIC.
SERVICE PARK ASSIST: If this
message occurs, take the vehicle
to your dealer to repair the system.
PARK ASSIST OFF: This message
occurs if the driver disables the
system.
PARK ASST BLOCKED SEE
OWNERS MANUAL: This
message can occur under the
following conditions:
.The ultrasonic sensors are not
clean. Keep the vehicle's rear
bumper free of mud, dirt, snow,
ice and slush. For cleaning
instructions, see Exterior Care
on page 10‑90.
.The park assist sensors are
covered by frost or ice. Frost or
ice can form around and behind
the sensors and may not always
be seen; this can occur after
washing the vehicle in cold
weather. The message may
not clear until the frost or ice
has melted.
.A trailer was attached to the
vehicle, or a bicycle or an
object was hanging out of the
liftgate during the last drive
cycle. Once the attached object
is removed, URPA will return
to normal operation.
.A tow bar is attached to the
vehicle.
.The vehicle's bumper is
damaged. Take the vehicle to
your dealer to repair the system.
.Other conditions may affect
system performance, such as
vibrations from a jackhammer or
the compression of air brakes on
a very large truck.

Black plate (47,1)GMC Acadia/Acadia Denali Owner Manual - 2011
Driving and Operating 9-47
For information on towing a disabled
vehicle, seeTowing the Vehicle on
page 10‑87. For information on
towing the vehicle behind another
vehicle such as a motor home, see
Recreational Vehicle Towing on
page 10‑87.
Driving Characteristics
and Towing Tips
{WARNING
The driver can lose control when
pulling a trailer if the correct
equipment is not used or the
vehicle is not driven properly.
For example, if the trailer is too
heavy, the brakes may not work
(Continued)
WARNING (Continued)
well—or even at all. The driver
and passengers could be
seriously injured. The vehicle may
also be damaged; the resulting
repairs would not be covered by
the vehicle warranty. Pull a trailer
only if all the steps in this section
have been followed. Ask your
dealer for advice and information
about towing a trailer with the
vehicle.
The vehicle can tow a trailer when
equipped with the proper trailer
towing equipment. For trailering
capacity, see Trailer Towing on
page 9‑52. Trailering changes handling, acceleration, braking,
durability and fuel economy.
With the added weight, the engine,
transmission, wheel assemblies and
tires are forced to work harder and
under greater loads. The trailer also
adds wind resistance, increasing
the pulling requirements. For safe
trailering, correctly use the proper
trailering equipment.
The following information has
important trailering tips and rules
for your safety and that of your
passengers. Read this section
carefully before pulling a trailer.

Black plate (48,1)GMC Acadia/Acadia Denali Owner Manual - 2011
9-48 Driving and Operating
Pulling a Trailer
Here are some important points:
.There are many laws, including
speed limit restrictions that apply
to trailering. Check for legal
requirements.
.Consider using sway control.
SeeTowing Equipment on
page 9‑54.
.Do not tow a trailer at all during
the first 800 km (500 miles)
the new vehicle is driven.
The engine, axle or other
parts could be damaged.
.During the first 800 km
(500 miles) that a trailer is
towed, do not drive over 80 km/h
(50 mph) and do not make starts
at full throttle. This reduces wear
on the vehicle.
.The vehicle can tow in
D (Drive). Use a lower gear if
the transmission shifts too often.
See “Tow/Haul Mode” later in
this section.
.Obey speed limit restrictions
when towing a trailer.
.The vehicle is designed
primarily as a passenger and
load carrying vehicle. If a trailer
is towed, the vehicle will require
more frequent maintenance due
to the additional load.
Driving with a Trailer
Towing a trailer requires experience.
Get familiar with handling and
braking with the added trailer
weight. The vehicle is now longer
and not as responsive as the
vehicle is by itself.
Check all trailer hitch parts
and attachments, safety chains,
electrical connectors, lamps, tires
and mirror adjustments. If the trailer
has electric brakes, start the vehicle
and trailer moving and then apply
the trailer brake controller by hand
to be sure the brakes are working.
During the trip, check regularly to be
sure that the load is secure, and the
lamps and trailer brakes are working
properly.