traction control GMC ACADIA 2008 User Guide

All-Wheel Drive (AWD) System
If your 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 front axle. It is fully automatic,
and adjusts itself as needed for road conditions.
When using a compact spare tire on your 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 clutch in your AWD system,
replace the compact spare with a full-size tire as soon
as possible. SeeCompact Spare Tire on page 5-88
for more information.
Steering
Power Steering
If you lose power steering assist because the engine
stops or the system is not functioning, you can steer but
it will take much more effort.
Variable Effort Steering
If your vehicle has this steering system, the system
continuously adjusts the effort you feel 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.
A lot of the “driver lost control” accidents mentioned on
the news happen on curves. Here is why:
Experienced driver or beginner, each of us is subject to
the same laws of physics when driving on curves.
The traction of the tires against the road surface makes
it possible for the vehicle to change its path when
you turn the front wheels. If there is no traction, inertia
will keep the vehicle going in the same direction. If
you have ever tried to steer a vehicle on wet ice, you
will understand this.
The traction you can get in a curve depends on the
condition of the tires and the road surface, the angle at
which the curve is banked, and your speed. While
you are in a curve, speed is the one factor you
can control.
Suppose you are steering through a sharp curve.
Then you suddenly accelerate. Both control
systems — steering and acceleration — have to do their
work where the tires meet the road. Adding the
sudden acceleration can demand too much of those
places. You can lose control. SeeStabiliTrak
®System
on page 4-6.
What should you do if this ever happens? Ease up on
the accelerator pedal, steer the vehicle the way you
want it to go, and slow down.
4-9

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.
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 your 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.
A cornering skid is best handled by easing your foot off
the accelerator pedal.If your 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,
your 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, you
want to 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
your 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.
4-12

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 5-48.
4-14

StabiliTrak®improves your ability to accelerate when
driving on a slippery road. Even with StabiliTrak®, slow
down and adjust your driving to the road conditions.
Under certain conditions, you might want to turn
the traction control part of the StabiliTrak
®System off,
such as when driving through deep snow and loose
gravel, to help maintain vehicle motion at lower speeds.
SeeStabiliTrak
®System on page 4-6andIf Your
Vehicle is Stuck in Sand, Mud, Ice, or Snow on
page 4-20.
The Antilock Brake System (ABS) improves your
vehicle’s stability when you make a hard stop on a
slippery road. Even though you have ABS, begin
stopping sooner than you would on dry pavement. See
Antilock Brake System (ABS) on page 4-5.
Allow greater following distance on any slippery road.
Watch for slippery spots. The road might be ne until
you hit a spot that is covered with ice. On an
otherwise clear road, ice patches can appear in
shaded areas where the sun cannot reach, such as
around clumps of trees, behind buildings, or under
bridges. Sometimes the surface of a curve or an
overpass can remain icy when the surrounding roads
are clear. If you see a patch of ice ahead of you,
brake before you are on it. Try not to brake while you
are actually on the ice, and avoid sudden steering
maneuvers.
If You Are Caught in a Blizzard
If you are stopped by heavy snow, you could be in a
serious situation. You should probably stay with
your vehicle unless you know for sure that you are near
help and you can hike through the snow. Here are
some things to do to summon help and keep yourself
and your passengers safe:
Turn on the hazard warning ashers.
Tie a red cloth to your vehicle to alert police that
you have been stopped by the snow.
Put on extra clothing or wrap a blanket around you.
If you do not have blankets or extra clothing, make
body insulators from newspapers, burlap bags,
rags, oor mats — anything you can wrap around
yourself or tuck under your clothing to keep warm.
4-18

Rocking Your Vehicle to Get It Out
First, turn the steering wheel left and right to clear
the area around the front wheels. Turn the traction
control part of the StabiliTrak
®System off. See
StabiliTrak®System on page 4-6. Then shift back and
forth between REVERSE (R) and a forward gear,
spinning the wheels as little as possible. To prevent
transmission wear, wait until the wheels stop spinning
before shifting gears. Release the accelerator pedal
while you shift, and press lightly on the accelerator pedal
when the transmission is in gear. By slowly spinning
the wheels in the forward and reverse directions, you will
cause a rocking motion that could free your vehicle. If
that does not get your vehicle out after a few tries,
it might need to be towed out. If your vehicle does need
to be towed out, seeTowing Your Vehicle on
page 4-26.
Loading Your Vehicle
It is very important to know how much weight your
vehicle can carry. This weight is called the
vehicle capacity weight and includes the weight of
all occupants, cargo, and all nonfactory-installed
options. Two labels on your vehicle show how
much weight it may properly carry, the Tire and
Loading Information label and the Certication/Tire
label.
{CAUTION:
Do not load your vehicle any heavier than
the Gross Vehicle Weight Rating (GVWR),
or either the maximum front or rear Gross
Axle Weight Rating (GAWR). If you do,
parts on your vehicle can break, and it
can change the way your vehicle handles.
These could cause you to lose control
and crash. Also, overloading can shorten
the life of your vehicle.
4-21

Accessories and Modications
When non-dealer/non-retailer accessories are added to
your vehicle they can affect your vehicle’s performance
and safety, including such things as, airbags, braking,
stability, ride and handling, emissions systems,
aerodynamics, durability, and electronic systems like
antilock brakes, traction control and stability control.
Some of these accessories could even cause
malfunction or damage not covered by warranty.
GM Accessories are designed to complement and
function with other systems on your vehicle. Your GM
dealer/retailer can accessorize your vehicle using
genuine GM Accessories. When you go to your GM
dealer/retailer and ask for GM Accessories, you
will know that GM-trained and supported service
technicians will perform the work using genuine GM
Accessories.
Also, seeAdding Equipment to Your Airbag-Equipped
Vehicle on page 1-76.
California Proposition 65 Warning
Most motor vehicles, including this one, contain and/or
emit chemicals known to the State of California to
cause cancer and birth defects or other reproductive
harm. Engine exhaust, many parts and systems
(including some inside the vehicle), many uids, and
some component wear by-products contain and/or emit
these chemicals.
California Perchlorate Materials
Requirements
Certain types of automotive applications, such as airbag
initiators, seat belt pretensioners, and lithium batteries
contained in remote keyless entry transmitters, may
contain perchlorate materials. Special handling may be
necessary. For additional information, see
www.dtsc.ca.gov/hazardouswaste/perchlorate.
5-4

You need new tires if any of the following statements
are true:
You can see the indicators at three or more places
around the tire.
You can see cord or fabric showing through the
tire’s rubber.
The tread or sidewall is cracked, cut, or snagged
deep enough to show cord or fabric.
The tire has a bump, bulge, or split.
The tire has a puncture, cut, or other damage that
cannot be repaired well because of the size or
location of the damage.
The rubber in tires degrades over time, even if they are
not being used. This is also true for the spare tire, if
your vehicle has one. Multiple conditions affect how fast
this aging takes place, including temperatures, loading
conditions, and ination pressure maintenance. With
proper care and maintenance tires will typically wear out
before they degrade due to age. If you are unsure
about the need to replace your tires as they get older,
consult the tire manufacturer for more information.
Buying New Tires
GM has developed and matched specic tires for
your vehicle. The original equipment tires
installed on your vehicle, when it was new, were
designed to meet General Motors Tire
Performance Criteria Specication (TPC Spec)
system rating. If you need replacement tires, GM
strongly recommends that you get tires with
the same TPC Spec rating. This way, your vehicle
will continue to have tires that are designed to
give the same performance and vehicle safety,
during normal use, as the original tires.
GM’s exclusive TPC Spec system considers over
a dozen critical specications that impact the
overall performance of your vehicle, including
brake system performance, ride and handling,
traction control, and tire pressure monitoring
performance. GM’s TPC Spec number is molded
onto the tire’s sidewall near the tire size. If the
tires have an all-season tread design, the
TPC Spec number will be followed by an MS for
mud and snow. SeeTire Sidewall Labeling on
page 5-49for additional information.
5-64

Your vehicle’s original equipment tires are listed
on the Tire and Loading Information Label.
SeeLoading Your Vehicle on page 4-21, for more
information about the Tire and Loading Information
Label and its location on your vehicle.
Different Size Tires and Wheels
If you add wheels or tires that are a different size than
your original equipment wheels and tires, this could
affect the way your vehicle performs, including its
braking, ride and handling characteristics, stability, and
resistance to rollover. Additionally, if your vehicle
has electronic systems such as anti-lock brakes, rollover
airbags, traction control, and electronic stability control,
the performance of these systems can be affected.
{CAUTION:
If you add different sized wheels, your vehicle
may not provide an acceptable level of
performance and safety if tires not
recommended for those wheels are selected.
You may increase the chance that you will
crash and suffer serious injury. Only use GM
specic wheel and tire systems developed for
your vehicle, and have them properly installed
by a GM certied technician.
SeeBuying New Tires on page 5-64andAccessories
and Modifications on page 5-4for additional information.
5-66

Uniform Tire Quality Grading
Quality grades can be found where applicable on
the tire sidewall between tread shoulder and
maximum section width. For example:
Treadwear 200 Traction AA Temperature A
The following information relates to the system
developed by the United States National Highway
Traffic Safety Administration (NHTSA), which
grades tires by treadwear, traction, and
temperature performance. This applies only to
vehicles sold in the United States. The grades are
molded on the sidewalls of most passenger car
tires. The Uniform Tire Quality Grading (UTQG)
system does not apply to deep tread, winter-type
snow tires, space-saver, or temporary use
spare tires, tires with nominal rim diameters of
10 to 12 inches (25 to 30 cm), or to some
limited-production tires.
While the tires available on General Motors
passenger cars and light trucks may vary with
respect to these grades, they must also conform
to federal safety requirements and additional
General Motors Tire Performance Criteria (TPC)
standards.
Treadwear
The treadwear grade is a comparative rating
based on the wear rate of the tire when tested
under controlled conditions on a specied
government test course. For example, a tire
graded 150 would wear one and a half (1.5) times
as well on the government course as a tire
graded 100. The relative performance of tires
depends upon the actual conditions of their use,
however, and may depart signicantly from
the norm due to variations in driving habits, service
practices, and differences in road characteristics
and climate.
Traction – AA, A, B, C
The traction grades, from highest to lowest, are AA,
A, B, and C. Those grades represent the tire’s
ability to stop on wet pavement as measured under
controlled conditions on specied government test
surfaces of asphalt and concrete. A tire marked C
may have poor traction performance.
Warning
:The traction grade assigned to this
tire is based on straight-ahead braking
traction tests, and does not include
acceleration, cornering, hydroplaning, or peak
traction characteristics.
5-67

Used Replacement Wheels
{CAUTION:
Putting a used wheel on your vehicle is
dangerous. You cannot know how it has been
used or how far it has been driven. It could fail
suddenly and cause a crash. If you have to
replace a wheel, use a new GM original
equipment wheel.
Tire Chains
{CAUTION:
Do not use tire chains. There is not enough
clearance. Tire chains used on a vehicle
without the proper amount of clearance can
cause damage to the brakes, suspension or
other vehicle parts. The area damaged by the
tire chains could cause you to lose control of
your vehicle and you or others may be injured
in a crash.
Use another type of traction device only if its
manufacturer recommends it for use on your
vehicle and tire size combination and road
conditions. Follow that manufacturer’s
instructions. To help avoid damage to your
vehicle, drive slowly, readjust or remove the
device if it is contacting your vehicle, and do
not spin your vehicle’s wheels. If you do nd
traction devices that will t, install them on the
front tires.
5-70