traction control CHEVROLET IMPALA 2008 9.G User Guide

Traction Control System (TCS)
Your vehicle may have a Traction Control System (TCS)
that limits wheel spin. This is especially useful in
slippery road conditions. The system operates only if it
senses that one or both of the front wheels are
spinning or beginning to lose traction. When this
happens, the system reduces engine power and may
also upshift the transmission and apply the front brakes
to limit wheel spin.
This light will ash
when the TCS is limiting
wheel spin.
You may feel or hear the system working, but this is
normal.
If your vehicle is in cruise control when the TCS begins
to limit wheel spin, the cruise control will automatically
disengage. When road conditions allow you to safely
use it again, the cruise control can be re-engaged.
SeeCruise Control on page 3-10.The TCS operates in all transmission shift lever
positions. But the system can upshift the transmission
only as high as the shift lever position chosen, so
use the lower gears only when necessary. See
Automatic Transmission Operation on page 2-26.
When the system is on,
this warning light comes
on and stays on to let
you know if there is
a problem.
A SERVICE TRACTION CONTROL message also
appears on the DIC. When this warning light is on, the
system will not limit wheel spin. Adjust your driving
accordingly. SeeDIC Warnings and Messages
on page 3-52for more information.
To limit wheel spin, especially in slippery road
conditions, you should always leave the TCS on.
But you can turn the system off if you ever need to.
Turn the system off if your vehicle ever gets stuck
in sand, mud or snow and rocking the vehicle is
required. SeeRocking Your Vehicle to Get It Out on
page 4-20andIf Your Vehicle is Stuck in Sand,
Mud, Ice, or Snow on page 4-20for more information.
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To turn the system on or
off, press the Traction
Control button located on
the left side of the
instrument panel.
When you turn the system off, a chime will sound,
the Traction Control warning light comes on and stays
on, and a TRACTION CONTROL OFF message
appears on the DIC. If the traction control system is
limiting wheel spin when you press the button to turn the
system off, the warning light will come on and the
system will turn off right away.
Press the Traction Control button again to turn the
system back on. The Traction Control warning light
should go off.
Adding non-dealer/non-retailer accessories can affect
your vehicle’s performance. SeeAccessories and
Modifications on page 5-3for more information.Electronic Stability Control
Your vehicle may have an Electronic Stability Control
(ESC) 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 your vehicle and begin to drive
away, the system performs several diagnostic checks to
ensure there are no problems. You may hear or feel
the system working. This is normal and does not mean
there is a problem with your vehicle. The system
should initialize before the vehicle reaches
20 mph (32 km/h).
If the system fails to turn on or activate, the ESC/TCS
light will be on solid, and the SERVICE STABILITRAK
message will be displayed.
For more information, seeDriver Information Center
(DIC) on page 3-44.
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This light will ash on the
instrument panel cluster
when the ESC system
is both on and activated.
You may also feel or hear the system working;
this is normal.
When the light is on solid and the SERVICE
STABILITRAK message is displayed, the system
will not assist the driver in maintaining directional
control of the vehicle. Adjust your driving accordingly.
SeeDIC Warnings and Messages on page 3-52.
The Electronic Stability Control (ESC) system is
automatically enabled whenever you start your vehicle.
To assist the driver with vehicle directional control,
especially in slippery road conditions, you should always
leave the system on. But, you can turn ESC off if you
ever need to.
If the vehicle is in cruise control when the system
begins to assist the driver maintain directional
control of the vehicle, the ESC/TCS 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 3-10.The ESC/TCS button
is located on the
instrument panel.
The traction control system can be turned off or
back on by pressing the ESC/TCS button. To disable
both traction control and ESC, press and hold the
button briey.
When the ESC system is turned off, the TRACTION
CONTROL OFF message will appear, and the ESC/TCS
light will be on solid to warn the driver that both
traction control and ESC are disabled.
It is recommended to leave the system on for normal
driving conditions, but it may be necessary to turn the
system off if your vehicle is stuck in sand, mud,
ice or snow, and you want to “rock” your 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 4-20.
ESC may also turn off automatically if it determines that
a problem exists with the system. The SERVICE
STABILITRAK message and the ESC/TCS light will be
on solid to warn the driver that ESC is disabled and
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requires service. If the problem does not clear after
restarting the vehicle, you should see your dealer/retailer
for service. SeeDIC Warnings and Messages on
page 3-52for more information.
Adding non-dealer/non-retailer accessories can affect
your vehicle’s performance. SeeAccessories and
Modifications on page 5-3for 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.
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 apply the brakes. Both control
systems — steering and braking — have to do their work
where the tires meet the road. Unless you have
antilock brakes, adding the hard braking can demand
too much of those places. You can lose control.
The same thing can happen if you are steering through
a sharp curve and you suddenly accelerate. Those
two control systems — steering and acceleration — can
overwhelm those places where the tires meet the road
and make you lose control.
What should you do if this ever happens? Ease up on
the brake or 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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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 and an acceleration skid are 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
will want to slow down and adjust your driving to
these conditions. It is important to slow down on slippery
surfaces because stopping distance will be 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 may 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.
If you have the Antilock Brake System (ABS),
remember: It helps avoid only the braking skid. If you do
not have ABS, then in a braking skid, where the
wheels are no longer rolling, release enough pressure
on the brakes to get the wheels rolling again. This
restores steering control. Push the brake pedal down
steadily when you have to stop suddenly. As long as the
wheels are rolling, you will have steering control.
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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 your 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.
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 accidents. 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.
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Whatever the condition — smooth ice, packed, blowing,
or loose snow — drive with caution.
If your vehicle has the Traction Control System (TCS),
it will improve your ability to accelerate when driving
on a slippery road. Even though you have TCS,
slow down and adjust your driving to the road conditions.
Under certain conditions, you might want to turn the
TCS off, such as when driving through deep snow and
loose gravel, to help maintain vehicle motion at
lower speeds. SeeTraction Control System (TCS) on
page 4-6.
If your vehicle does not have TCS, accelerate gently.
Try not to break the fragile traction. If you accelerate too
fast, the drive wheels will spin and polish the surface
under the tires even more.
Unless your vehicle has the Antilock Brake System
(ABS), you will want to brake very gently, too. If you
do have ABS, seeAntilock Brake System (ABS)
on page 4-4. ABS improves your vehicle’s stability when
you make a hard stop on a slippery road. Whether
your vehicle has ABS or not, begin stopping sooner than
you would on dry pavement. Without ABS, if you feel
your vehicle begin to slide, let up on the brakes a little.
Push the brake pedal down steadily to get the most
traction you can.Remember, unless your vehicle has ABS, if you brake
so hard that the wheels stop rolling, your vehicle will just
slide. Brake so the wheels always keep rolling and
you can still steer.
Whatever your vehicle’s braking system, 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.
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If Your Vehicle is Stuck in Sand,
Mud, Ice, or Snow
Slowly and cautiously spin the wheels to free your
vehicle when stuck in sand, mud, ice, or snow.
SeeRocking Your Vehicle to Get It Out on page 4-20.
If your vehicle has a traction system, it can often help to
free a stuck vehicle. Refer to your vehicle’s traction
system in the Index. If the stuck condition is too severe
for the traction system to free the vehicle, turn the
traction system off and use the rocking method.
{CAUTION:
If you let your vehicle’s tires spin at high
speed, they can explode, and you or others
could be injured. The vehicle can overheat,
causing an engine compartment re or other
damage. Spin the wheels as little as possible
and avoid going above 35 mph (55 km/h) as
shown on the speedometer.
For information about using tire chains on your vehicle,
seeTire Chains on page 5-76.
Rocking Your Vehicle to Get It Out
First, turn the steering wheel left and right to clear
the area around the front wheels. Turn off any traction
system. SeeTraction Control System (TCS) 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.
4-20

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 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 1-67.
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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 5-55
for additional information.GM recommends replacing tires in sets of four. This is
because uniform tread depth on all tires will help
keep your vehicle performing most like it did when the
tires were new. Replacing less than a full set of tires can
affect the braking and handling performance of your
vehicle. SeeTire Inspection and Rotation on page 5-68
for information on proper tire rotation.
{CAUTION:
Mixing tires could cause you to lose control
while driving. If you mix tires of different sizes,
brands, or types (radial and bias-belted tires),
the vehicle may not handle properly, and you
could have a crash. Using tires of different
sizes, brands, or types may also cause damage
to your vehicle. Be sure to use the correct size,
brand, and type of tires on all wheels. It is all
right to drive with your compact spare
temporarily, as it was developed for use on your
vehicle. SeeCompact Spare Tire on page 5-89.
5-71