2012 GMC ACADIA brake

Black plate (29,1)GMC Acadia/Acadia Denali Owner Manual - 2012
Driving and Operating 9-29
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 9‑45.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.
Hill Start Assist (HSA)
This vehicle has a Hill Start Assist
(HSA) feature, which may be useful
when the vehicle is stopped on a
grade. This feature is designed to
prevent the vehicle from rolling,
either forward or rearward, during
vehicle drive off. After the driver
completely stops and holds the
vehicle in a complete standstill on a
grade, HSA will be automatically
activated. During the transition
period between when the driver
releases the brake pedal and starts
to accelerate to drive off on a grade,
HSA holds the braking pressure
to ensure that there is no rolling.
The brakes will automatically
release when the accelerator pedal
is applied within the two‐second
window. It will not activate if the
vehicle is in a drive gear and facing
downhill or if the vehicle is facing
uphill and in R (Reverse).

Black plate (30,1)GMC Acadia/Acadia Denali Owner Manual - 2012
9-30 Driving and Operating
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 mi) 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
Ride Control
System Messages on page 5‑42.
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.
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

Black plate (31,1)GMC Acadia/Acadia Denali Owner Manual - 2012
Driving and Operating 9-31
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 9‑10.
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.
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. See
Cruise
Control on page 9‑32.
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.

Black plate (32,1)GMC Acadia/Acadia Denali Owner Manual - 2012
9-32 Driving and Operating
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.
[(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.

Black plate (33,1)GMC Acadia/Acadia Denali Owner Manual - 2012
Driving and Operating 9-33
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. 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
Tor if the ignition is turned off.

Black plate (35,1)GMC Acadia/Acadia Denali Owner Manual - 2012
Driving and Operating 9-35
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 10‑86.
.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 an object was
hanging out of the liftgate during
the last drive cycle. Once the
object is removed, URPA will
return to normal operation.
.A tow bar is attached to the
vehicle.
.The bumper is damaged.
Take the vehicle to your dealer
to repair the system.
.Other conditions, such as
vibrations from a jackhammer or
the compression of air brakes on
a very large truck, are affecting
system performance.
Rear Vision
Camera (RVC)
The vehicle may have a rear vision
camera system. Read this entire
section before using it.
{WARNING
The RVC system does not display
pedestrians, bicyclists, animals,
or any other object located
outside the camera's field of view,
below the bumper, or under the
vehicle.
(Continued)
WARNING (Continued)
Do not back the vehicle using
only the RVC screen or by
using the screen during longer,
higher speed backing maneuvers,
or where there could be
cross-traffic. Perceived distances
may be different from actual
distances.
Failure to use proper care before
backing may result in injury,
death, or vehicle damage. Always
check before backing by checking
behind and around the vehicle.
Vehicles without Navigation
System
The rear vision camera system is
designed to help the driver when
backing up by displaying a view
of the area behind the vehicle.

Black plate (45,1)GMC Acadia/Acadia Denali Owner Manual - 2012
Driving and Operating 9-45
For information on towing a disabled
vehicle, seeTowing the Vehicle on
page 10‑82. For information on
towing the vehicle behind another
vehicle such as a motor home, see
Recreational Vehicle Towing on
page 10‑82.
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.
(Continued)
WARNING (Continued)
For example, if the trailer is too
heavy, the brakes may not work
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 9‑49. 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 (46,1)GMC Acadia/Acadia Denali Owner Manual - 2012
9-46 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 9‑51.
.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.
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.
Tow/Haul Mode
Tow/Haul assists when pulling a
heavy trailer or a large or heavy
load. The purpose of the Tow/Haul
mode is to:
.Reduce the frequency and
improve the predictability of
transmission shifts.
.Provide the same solid shift feel
as when the vehicle is unloaded.