brake GMC ACADIA 2010 Owner's Guide

9-22 Driving and Operating
Running the Vehicle
While Parked
It is better not to park with the
engine running. But if you ever have
to, here are some things to know.
{WARNING
Idling a vehicle in an enclosed
area with poor ventilation is
dangerous. Engine exhaust may
enter the vehicle. Engine exhaust
contains Carbon Monoxide (CO)
which cannot be seen or smelled.
It can cause unconsciousness
and even death. Never run the
engine in an enclosed area that
has no fresh air ventilation. For
more information, seeEngine
Exhaust on page 9‑21.
{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 9‑19.
If parking on a hill and pulling a
trailer, see Driving Characteristics
and Towing Tips on page 9‑44.
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.

Driving and Operating 9-23
{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).
SeeShifting Into Park
on
page 9‑19
. If you are pulling a
trailer, see Driving Characteristics
and Towing Tips on page 9‑44.
Make sure the shift lever is fully in
P (Park) before starting the engine.
The vehicle has an automatic
transmission shift lock control system. 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. See
Shifting Out of Park
on
page 9‑20.
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 9‑10. 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.

Driving and Operating 9-25
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.
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 9‑44for 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.
See Automatic Transmission
on
page 9‑22.
Drive Systems
All-Wheel Drive
With this feature, engine power is
always sent 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 system, replace
the compact spare with a full-size
tire as soon as possible. See
Compact Spare Tire
on page 10‑77for more information.

9-26 Driving and Operating
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 5‑19. 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. The ABS pump or motor
might be heard operating, and the
brake pedal might be felt to 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.

Driving and Operating 9-27
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 5‑19. 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 Trailer Towingon page 9‑49.
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 pulsations 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.

9-28 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 miles) of
driving before the system initializes.If the system fails to turn on or
activate, the StabiliTrak light along
with one of the following messages
will be displayed on the Driver
Information Center (DIC):
TRACTION CONTROL OFF,
SERVICE TRACTION CONTROL,
SERVICE STABILITRAK. 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 5‑23or Driver
Information Center (DIC) (Without
DIC Buttons) on page 5‑28.
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 disable button is
located on the instrument panel
below the climate controls.
The traction control part of
StabiliTrak can be turned off by
pressing and releasing the traction
control disable button.

Driving and Operating 9-29
Traction control can be turned on by
pressing and releasing the traction
control disable button if not
automatically shut off for any other
reason.
When the traction control system is
turned off, the StabiliTrak light and
the appropriate traction control off
message will be displayed on the
DIC to warn the driver. 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” next 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 brakes to each individual
wheel (brake-traction control) 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 and
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.

9-30 Driving and Operating
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 9‑30.
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/retailer 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 to make the vehicle
accelerate or resume to a previously
set speed.
SET– :Press to set the speed or
make the vehicle decelerate.

Driving and Operating 9-31
[(Cancel):Press to cancel cruise
control.
Setting Cruise Control
Cruise control will not work if the
parking brake is set, or if the master
cylinder brake fluid level is low.
The cruise control light on the
instrument panel cluster comes on
after the cruise control has been set
to the desired speed.
{WARNING
If you leave your cruise control on
when you are not using cruise,
you might hit a button and go into
cruise when you do not want to.
You could be startled and even
lose control. Keep the cruise
control switch off until you want to
use cruise control.
1. Press the
Ibutton.
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. But it does not need to
be reset.
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
There are two ways to increase the
vehicle speed while using cruise
control:.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
There are two ways to reduce the
vehicle speed while using cruise
control:
.Press and hold the SET– button
on the steering wheel until the
lower speed desired is reached,
then release it.
.To slow down in very small
amounts, press the SET– button
briefly. Each time this is done,
the vehicle goes about 1.6 km/h
(1 mph) slower.

9-32 Driving and Operating
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.
.Press theTbutton.
Erasing Speed Memory
The cruise control set speed
memory is erased when the cruise
control or 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.