traction control GMC ACADIA 2007 User Guide

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, you may notice a reduction
in acceleration, or may hear a noise or vibration.
This is normal.
If your vehicle is in cruise control when the system
activates, the StabiliTrak
®light will ash and the
cruise control will automatically disengage.
When road conditions allow you to use cruise
again, you may re-engage the cruise control.
SeeCruise Control on page 180.
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, you should see your dealer/retailer
for service.
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 477
for more information.
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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.
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 337.
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.
Speed limit signs near curves warn that you should
adjust your speed. Of course, the posted speeds
are based on good weather and road conditions.
Under less favorable conditions you will want to go
slower.
If you need to reduce your speed as you approach
a curve, do it before you enter the curve, while
the front wheels are straight ahead.
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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 Anti-Lock Brake System (ABS)
helps avoid only the braking skid.
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And, if the tires do not have much tread left, you
get even less traction. It is always wise to go
slower and be cautious if rain starts to fall while
you are driving. The surface may get wet suddenly
when your reexes are tuned for driving on dry
pavement.
The heavier the rain, the harder it is to see.
Even if the windshield wiper blades are in good
shape, a heavy rain can make it harder to see road
signs and traffic signals, pavement markings,
the edge of the road, and even people walking.
It is wise to keep windshield wiping equipment in
good shape and keep the windshield washer
uid reservoir lled with washer uid. Replace
windshield wiper inserts when they show signs of
streaking or missing areas on the windshield,
or when strips of rubber start to separate from
the inserts.
{CAUTION:
Wet brakes can cause accidents. They
may not work as well in a quick stop and
may cause pulling to one side. You could
lose control of the vehicle.
After driving through a large puddle of
water or a car wash, apply the brake pedal
lightly until the brakes work normally.
Driving too fast through large water puddles or
even going through some car washes can cause
problems, too. The water may affect the brakes.
Try to avoid puddles. But if you cannot, try to slow
down before you hit them.
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Driving on Snow or Ice
Most of the time, those places where the tires
meet the road probably have good traction.
However, if there is snow or ice between the tires
and the road, you can have a very slippery
situation. You will have a lot less traction, or grip,
and will need to be very careful.What is the worst time for this? Wet ice. Very cold
snow or ice can be slick and hard to drive on.
But wet ice can be even more trouble because it
may offer the least traction of all. You can get
wet ice when it is about freezing, 32°F (0°C), and
freezing rain begins to fall. Try to avoid driving
on wet ice until salt and sand crews can get there.
Whatever the condition — smooth ice, packed,
blowing, or loose snow — drive with caution.
StabiliTrak
®improves your ability to accelerate
when driving on a slippery road. Even with
StabiliTrak
®, you will want to 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 337and
If Your Vehicle is Stuck in Sand, Mud, Ice, or
Snow on page 360.
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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.
SeeStabiliTrak®System on page 337. 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 367.
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.
361

Service
Your dealer/retailer knows your vehicle best and
wants you to be happy with it. We hope you will go
to your dealer/retailer for all your service needs.
You will get genuine GM parts and GM-trained and
supported service people.
We hope you will want to keep your GM vehicle all
GM. Genuine GM parts have one of these marks:
Accessories and Modications
When you add non-GM accessories 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 anti-lock brakes, traction control and
stability control. Some of these accessories may
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.
385

When It Is Time for New Tires
One way to tell when it
is time for new tires is
to check the treadwear
indicators, which will
appear when your tires
have only 1/16 inch
(1.6 mm) or less of tread
remaining.
You need a new tire 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.
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 by the tire manufacturer.
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 436for additional information.
450

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 450and
Accessories and Modifications on page 385
for additional information.
452

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.
453