brakes GMC ACADIA 2009 Owner's Manual

The following describes how the URPA display lights appear as the vehicle
gets closer to a detected object:
DescriptionEnglishMetric
amber light 8 ft2.5 m
amber/amber lights 40 in1.0 m
amber/amber/red lights 23 in0.6 m
amber/amber/red lights ashing 1 ft 0.3 m
The system can be disabled through
the Driver Information Center
(DIC). See “Park Assist” under DIC
Operation and Displays (With
DIC Buttons) on page 3-46 orDIC
Operation and Displays (Without
DIC Buttons) on page 3-51 for more
information.
When the System Does Not
Seem to Work Properly
If the URPA system will not activate
due to a temporary condition, the
message PARK ASSIST OFF will be
displayed on the DIC and a red
light will be shown on the rear URPA display when the shift lever is
moved into R (Reverse). This may
occur under the following
conditions:
The driver disables the system.
The parking brake pedal is
depressed.
The ultrasonic sensors are not
clean. Keep the vehicle’s rear
bumper free of mud, dirt,
snow, ice and slush. For cleaning
instructions, see
Washing Your
Vehicle on page 5-84 .
A trailer was attached to the
vehicle, or a bicycle or an
object was hanging out of the
liftgate during the last drive cycle,
the red light may illuminate in
the rear display. 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/retailer 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.
If the system is still disabled, after
driving forward at least 15 mph
(25 km/h), take the vehicle to your
dealer/retailer.
2-36 Features and Controls

Under certain outside temperature
conditions, steam might ow
out of the washer nozzles for a
short period of time before washer
uid is sprayed. This is normal.
HEATING WASH FLUID WASH
WIPES PENDING is displayed on
the DIC when the washer system is
heating the uid.
WASHER FLUID LOW ADD FLUID
is displayed on the DIC when the
washer uid is low. SeeDIC
Warnings and Messages on
page 3-56.
Rear Window
Wiper/Washer
The rear wiper and rear wash
button is located on the instrument
panel below the climate control
system.
Z(Rear Wiper):Press to turn the
rear wiper on and off. The wiper
speed cannot be changed.
Y(Wash):Press to spray washer
uid on the rear window. The
window wiper will also come on.
Release the button when enough
uid has been sprayed on the
window. The rear wiper will run a
few more cycles after it is released.
If the rear wiper function was
already on, prior to pressing the
wash button, it stays on until
the wiper button is pressed again.
The rear window washer uses
the same uid that is in the
windshield washer reservoir.
SeeWindshield Washer Fluid
on page 5-24.Cruise Control
With cruise control, a speed of
about 25 mph (40 km/h) or more can
be maintained without keeping
your foot on the accelerator. Cruise
control does not work at speeds
below about 25 mph (40 km/h).
When the brakes are applied, the
cruise control is disengaged.
{CAUTION
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.
Instrument Panel 3-9

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.
[(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 uid 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.
{CAUTION
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 25 mph
(40 km/h) 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 briey. Each time
this is done, the vehicle goes
about 1 mph (1.6 km/h) faster.
3-10 Instrument Panel

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
briey. Each time this is done,
the vehicle goes about 1 mph
(1.6 km/h) 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.
Press theTbutton.
Erasing Speed Memory
The cruise control set speed memory
is erased when the cruise control or
the ignition is turned off.
Exterior Lamps
The exterior lamps control is located
on the instrument panel to the left
of the steering wheel.
It controls the following systems:
Headlamps
Taillamps
Parking Lamps
License Plate Lamps
Instrument Panel Lights
Fog Lamps
Instrument Panel 3-11

Voltmeter Gage
When the engine is not running, but
the ignition is turned on, this
gage shows the battery’s state of
charge in DC volts.
When the engine is running, this
gage shows the condition of the
charging system. The vehicle’s
charging system regulates voltage
based on the state of charge of the
battery. The voltmeter may uctuate.
This is normal. Readings between
the low and high warning zones
indicate the normal operating range.
Readings in the low warning zone
may occur when a large number of
electrical accessories are operating
in the vehicle and the engine is
left idling for an extended period.If there is a problem with the battery
charging system, a SERVICE
BATTERY CHARGING SYSTEM
message will appear in the
Driver Information Center (DIC)
and/or the charging system light will
come on. SeeDIC Warnings and
Messages on page 3-56and
Charging System Light on page 3-37
for more information.
However, readings in either warning
zone may indicate a possible
problem in the electrical system.
Have the vehicle serviced as soon
as possible.
Brake System Warning
Light
This vehicle’s hydraulic brake
system is divided into two parts.
If one part is not working, the other
part can still work and stop the
vehicle. For good braking both parts
need to be working.If the warning light comes on, there
is a brake problem. Have the
brake system inspected right away.
This light should come on briey
when the ignition key is turned
to ON/RUN. If it does not come on
then, have it xed so it will be
ready to warn if there is a problem.
This light may also come on due
to low brake uid. SeeBrakes
on page 5-25for more information.
When the ignition is on, the
brake system warning light will also
come on when the parking brake
is set. The light will stay on if
the parking brake does not release
fully. If it stays on after the
parking brake is fully released, it
means there is a brake problem.
United StatesCanada
3-38 Instrument Panel

If the light comes on while driving,
pull off the road and stop carefully.
Make sure the parking brake is
fully released. The pedal may be
harder to push or, the pedal may go
closer to the oor. It may take
longer to stop. If the light is still on,
have the vehicle towed for service.
SeeTowing Your Vehicle on
page 4-20.
{CAUTION
The brake system might not be
working properly if the brake
system warning light is on. Driving
with the brake system warning
light on can lead to a crash. If the
light is still on after the vehicle
has been pulled off the road and
carefully stopped, have the
vehicle towed for service.
Antilock Brake System
(ABS) Warning Light
For vehicles with the Antilock Brake
System (ABS), this light comes
on briey when the engine is started.
That is normal. If the light does
not come on then, have it xed so it
will be ready to warn if there is a
problem.
If the ABS light stays on, turn the
ignition off. If the light comes
on while driving, stop as soon as it
is safely possible and turn the
ignition off. A chime may also sound
when the light comes on steady.
Then start the engine again to reset
the system. If the ABS light stays
on, or comes on again while driving,
the vehicle needs service. If the
regular brake system warning light
is not on, the vehicle still has
brakes, but not antilock brakes.If the regular brake system warning
light is also on, the vehicle does
not have antilock brakes and there
is a problem with the regular
brakes. SeeBrake System Warning
Light on page 3-38.
For vehicles with a Driver Information
Center (DIC), seeDIC Warnings and
Messages on page 3-56for all brake
related DIC messages.
StabiliTrak®Indicator
Light
This light comes on briey while
starting the engine. If it does
not, have the vehicle serviced by
your dealer/retailer. If the system is
working normally the indicator light
will then go off.
If it stays on, or comes on while
driving, there may be a problem with
the StabiliTrak system and the
Instrument Panel 3-39

Police records show that almost
40 percent of all motor
vehicle-related deaths involve
alcohol. In most cases, these deaths
are the result of someone who was
drinking and driving. In recent years,
more than 17,000 annual motor
vehicle-related deaths have been
associated with the use of alcohol,
with about 250,000 people injured.
For persons under 21, it is against
the law in every U.S. state to drink
alcohol. There are good medical,
psychological, and developmental
reasons for these laws.
The obvious way to eliminate the
leading highway safety problem
is for people never to drink alcohol
and then drive.
Medical research shows that alcohol
in a person’s system can make crash
injuries worse, especially injuries
to the brain, spinal cord, or heart.This means that when anyone who
has been drinking — driver or
passenger — is in a crash, that
person’s chance of being killed or
permanently disabled is higher than
if the person had not been drinking.
Control of a Vehicle
The following three systems help
to control the vehicle while
driving — brakes, steering, and
accelerator. At times, as when
driving on snow or ice, it is easy to
ask more of those control systems
than the tires and road can provide.
Meaning, you can lose control of the
vehicle. SeeStabiliTrak
®System on
page 4-5.
Adding non-dealer/non-retailer
accessories can affect vehicle
performance. SeeAccessories and
Modifications on page 5-3.
Braking
SeeBrake System Warning Light
on page 3-38.
Braking action involves perception
time and reaction time. Deciding
to push the brake pedal is
perception time. Actually doing
it is reaction time.
Average reaction time is about
three-fourths of a second. But that
is only an average. It might be
less with one driver and as long as
two or three seconds or more
with another. Age, physical
condition, alertness, coordination,
and eyesight all play a part. So
do alcohol, drugs, and frustration.
But even in three-fourths of a
second, a vehicle moving at 60 mph
(100 km/h) travels 66 feet (20 m).
That could be a lot of distance in an
emergency, so keeping enough
space between the vehicle
and others is important.
Driving Your Vehicle 4-3

And, of course, actual stopping
distances vary greatly with the
surface of the road, whether it is
pavement or gravel; the condition of
the road, whether it is wet, dry, or icy;
tire tread; the condition of the brakes;
the weight of the vehicle; and the
amount of brake force applied.
Avoid needless heavy braking. Some
people drive in spurts — heavy
acceleration followed by heavy
braking — rather than keeping pace
with traffic. This is a mistake. The
brakes might not have time to cool
between hard stops. The brakes will
wear out much faster with a lot of
heavy braking. Keeping pace with
the traffic and allowing realistic
following distances eliminates a lot of
unnecessary braking. That means
better braking and longer brake life.
If the engine ever stops while the
vehicle is being driven, brake
normally but do not pump the
brakes. If the brakes are pumped,
the pedal could get harder to
push down. If the engine stops,there will still be some power brake
assist but it will be used when
the brake is applied. Once the power
assist is used up, it can take
longer to stop and the brake pedal
will be harder to push.
Adding non-dealer/non-retailer
accessories can affect vehicle
performance. SeeAccessories and
Modifications on page 5-3.
Antilock Brake
System (ABS)
This vehicle has the Antilock Brake
System (ABS), an advanced
electronic braking system that will
help 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. See
Antilock Brake System (ABS)
Warning Light on page 3-39.
Let us say the road is wet and you
are driving safely. Suddenly, an
animal jumps out in front of you.
You slam on the brakes and continue
braking. Here is what happens
with ABS:
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.
4-4 Driving Your Vehicle

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 rmly and
let antilock work. The antilock pump
or motor operating might be
heard 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.
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.
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 rst 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 20 mph
(32 km/h). In some cases, it may take
approximately two miles of driving
before the system initializes.
Driving Your Vehicle 4-5

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,
seeDriver Information Center (DIC)
on page 3-46.
The StabiliTrak light will ash 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.
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. SeeIf Your
Vehicle is Stuck in Sand, Mud,
Ice, or Snow on page 4-15.
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.
4-6 Driving Your Vehicle