brake GMC ACADIA 2009 Owner's Guide

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

The traction control system is
enabled automatically when the
vehicle is started. It will activate and
the StabiliTrak light will ash 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.
If cruise control is being used when
the system activates, the StabiliTrak
light will ash and cruise control
will automatically disengage. Cruise
control may be reengaged when
road conditions allow. SeeCruise
Control on page 3-9.
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.All-Wheel Drive (AWD)
System
If the vehicle has this feature,
engine power is sent to all four
wheels when extra traction is
needed. This is like four-wheel drive,
but there is no separate lever or
switch to engage or disengage the
axle. It is fully automatic, and
adjusts itself as needed for road
conditions.
When using a compact spare tire
on the AWD equipped vehicle,
the AWD system automatically
detects the presence of the compact
spare and the AWD is disabled.
To restore the AWD operation and
prevent excessive wear on the
AWD system, replace the compact
spare with a full-size tire as
soon as possible. SeeCompact
Spare Tire on page 5-81for more
information.
Driving Your Vehicle 4-7

Steering
Power Steering
If power steering assist is lost
because the engine stops or the
system is not functioning, the vehicle
can be steered but it will take
more effort.
Variable Effort Steering
If the vehicle has this steering
system, the system continuously
adjusts the effort felt when steering
at all vehicle speeds. It provides
ease when parking, yet a rm, solid
feel at highway speeds.
Steering Tips
It is important to take curves at a
reasonable speed.
Traction in a curve depends on the
condition of the tires and the
road surface, the angle at which the
curve is banked, and vehicle
speed. While in a curve, speed is
the one factor that can be controlled.If there is a need to reduce speed,
do it before entering the curve,
while the front wheels are straight.
Try to adjust the speed so you
can drive through the curve.
Maintain a reasonable, steady
speed. Wait to accelerate until out
of the curve, and then accelerate
gently into the straightaway.
Steering in Emergencies
There are times when steering can
be more effective than braking.
For example, you come over a hill
and nd a truck stopped in your
lane, or a car suddenly pulls
out from nowhere, or a child darts
out from between parked cars
and stops right in front of you.
These problems can be avoided
by braking — if you can stop in time.
But sometimes you cannot stop in
time because there is no room.
That is the time for evasive
action — steering around the
problem.The vehicle can perform very well in
emergencies like these. First,
apply the brakes. SeeBraking on
page 4-3. It is better to remove
as much speed as possible from a
collision. Then steer around the
problem, to the left or right
depending on the space available.
An emergency like this requires
close attention and a quick decision.
If holding the steering wheel at
the recommended 9 and 3 o’clock
positions, it can be turned a
full 180 degrees very quickly
without removing either hand.
4-8 Driving Your Vehicle

But you have to act fast, steer
quickly, and just as quickly
straighten the wheel once you have
avoided the object.
The fact that such emergency
situations are always possible is a
good reason to practice defensive
driving at all times and wear
safety belts properly.
Off-Road Recovery
The vehicle’s right wheels can drop
off the edge of a road onto the
shoulder while driving.
If the level of the shoulder is only
slightly below the pavement,
recovery should be fairly easy.Ease off the accelerator and then, if
there is nothing in the way, steer
so that the vehicle straddles
the edge of the pavement. Turn
the steering wheel 3 to 5 inches,
8 to 13 cm, (about one-eighth turn)
until the right front tire contacts
the pavement edge. Then turn
the steering wheel to go straight
down the roadway.Passing
Passing another vehicle on a
two-lane road can be dangerous.
To reduce the risk of danger
while passing:
Look down the road, to the sides,
and to crossroads for situations
that might affect a successful
pass. If in doubt, wait.
Watch for traffic signs, pavement
markings, and lines that could
indicate a turn or an intersection.
Never cross a solid or
double-solid line on your
side of the lane.
Do not get too close to the vehicle
you want to pass. Doing so can
reduce your visibility.
Wait your turn to pass a slow
vehicle.
When you are being passed, ease
to the right.
Loss of Control
Let us review what driving experts
say about what happens when
the three control systems — brakes,
steering, and acceleration — do
not have enough friction where the
tires meet the road to do what
the driver has asked.
In any emergency, do not give up.
Keep trying to steer and constantly
seek an escape route or area of
less danger.
Driving Your Vehicle 4-9

Skidding
In a skid, a driver can lose control
of the vehicle. Defensive drivers
avoid most skids by taking
reasonable care suited to existing
conditions, and by not overdriving
those conditions. But skids are
always possible.
The three types of skids correspond
to the vehicle’s three control
systems. In the braking skid, the
wheels are not rolling. In the steering
or cornering skid, too much speed
or steering in a curve causes tires
to slip and lose cornering force.
And in the acceleration skid, too
much throttle causes the driving
wheels to spin.
If the vehicle starts to slide, ease
your foot off the accelerator
pedal and quickly steer the way you
want the vehicle to go. If you
start steering quickly enough, the
vehicle may straighten out. Always
be ready for a second skid if it
occurs.Of course, traction is reduced when
water, snow, ice, gravel, or other
material is on the road. For safety,
slow down and adjust your
driving to these conditions. It is
important to slow down on slippery
surfaces because stopping
distance is longer and vehicle
control more limited.
While driving on a surface with
reduced traction, try your best to
avoid sudden steering, acceleration,
or braking, including reducing vehicle
speed by shifting to a lower gear.
Any sudden changes could cause
the tires to slide. You might not
realize the surface is slippery until
the vehicle is skidding. Learn to
recognize warning clues — such as
enough water, ice, or packed snow
on the road to make a mirrored
surface — and slow down when you
have any doubt.
Remember: Any Antilock Brake
System (ABS) helps avoid only the
braking skid.
Driving at Night
Night driving is more dangerous than
day driving because some drivers
are likely to be impaired — by alcohol
or drugs, with night vision problems,
or by fatigue.
Night driving tips include:
Drive defensively.
Do not drink and drive.
Reduce headlamp glare by
adjusting the inside rearview
mirror.
Slow down and keep more space
between you and other vehicles
because headlamps can only
light up so much road ahead.
Watch for animals.
When tired, pull off the road.
Do not wear sunglasses.
Avoid staring directly into
approaching headlamps.
4-10 Driving Your Vehicle

Keep the windshield and all glass
on your vehicle clean — inside
and out.
Keep your eyes moving,
especially during turns or curves.
No one can see as well at night as
in the daytime. But, as we get
older, these differences increase.
A 50-year-old driver might need
at least twice as much light to see
the same thing at night as a
20-year-old.
Driving in Rain and on
Wet Roads
Rain and wet roads can reduce
vehicle traction and affect your
ability to stop and accelerate.
Always drive slower in these types
of driving conditions and avoid
driving through large puddles and
deep-standing or owing water.
{CAUTION
Wet brakes can cause crashes.
They might not work as well in a
quick stop and could cause
pulling to one side. You could
lose control of the vehicle.
After driving through a large
puddle of water or a car/vehicle
wash, lightly apply the brake
pedal until the brakes work
normally.
Flowing or rushing water creates
strong forces. Driving through
owing water could cause your
vehicle to be carried away. If this
happens, you and other vehicle
occupants could drown. Do not
ignore police warnings and be
very cautious about trying to drive
through owing water.
Hydroplaning
Hydroplaning is dangerous. Water
can build up under your vehicle’s
tires so they actually ride on
the water. This can happen if the
road is wet enough and you
are going fast enough. When your
vehicle is hydroplaning, it has little or
no contact with the road.
There is no hard and fast rule about
hydroplaning. The best advice is
to slow down when the road is wet.
Other Rainy Weather Tips
Besides slowing down, other wet
weather driving tips include:
Allow extra following distance.
Pass with caution.
Keep windshield wiping
equipment in good shape.
Keep the windshield washer uid
reservoir lled.
Have good tires with proper tread
depth. SeeTires on page 5-35.
Turn off cruise control.
Driving Your Vehicle 4-11

Before Leaving on a
Long Trip
To prepare your vehicle for a long
trip, consider having it serviced
by your dealer/retailer before
departing.
Things to check on your own
include:
Windshield Washer Fluid:
Reservoir full? Windows
clean — inside and outside?
Wiper Blades:In good shape?
Fuel, Engine Oil, Other Fluids:All
levels checked?
Lamps:Do they all work and are
lenses clean?
Tires:Are treads good? Are tires
inated to recommended
pressure?
Weather and Maps:Safe to
travel? Have up-to-date maps?
Highway Hypnosis
Always be alert and pay attention
to your surroundings while driving.
If you become tired or sleepy,
nd a safe place to park your
vehicle and rest.
Other driving tips include:
Keep the vehicle well ventilated.
Keep interior temperature cool.
Keep your eyes moving — scan
the road ahead and to the sides.
Check the rearview mirror and
vehicle instruments often.
Hill and Mountain Roads
Driving on steep hills or through
mountains is different than driving
on at or rolling terrain. Tips for
driving in these conditions include:
Keep the vehicle serviced
and in good shape.
Check all uid levels and brakes,
tires, cooling system, and
transmission.
Going down steep or long hills,
shift to a lower gear.
{CAUTION
If you do not shift down, the
brakes could get so hot that they
would not work well. You would
then have poor braking or even
none going down a hill. You could
crash. Shift down to let the engine
assist the brakes on a steep
downhill slope.
4-12 Driving Your Vehicle