traction control CHEVROLET CORVETTE 2004 5.G User Guide

Remember: Anti-lock does not change the time you
need to get your foot up to the brake pedal or always
decrease stopping distance. If you get too close to
the vehicle in front of you, you will not have time to apply
your brakes if that vehicle suddenly slows or stops.
Always leave enough room up ahead to stop, even
though you have anti-lock brakes.
Using Anti-Lock
Do not pump the brakes. Just hold the brake pedal
down firmly and let anti-lock work for you. You may hear
a motor or clicking noise and feel the brake pedal
move a little during a stop, but this is normal.
Braking in Emergencies
With anti-lock, you can steer and brake at the same
time. In many emergencies, steering can help you more
than even the very best braking.
Traction Control System (TCS)
Your vehicle has a traction control system called TCS
that limits wheel spin. This is especially useful in slippery
road conditions. The system operates only if it senses
that the rear wheels are spinning too much or are
beginning to lose traction. When this happens, the
system works the rear brakes and reduces engine power
(by closing the throttle and managing engine spark) to
limit wheel spin.
The TRACTION SYS ACTIVE message will come on
when the TCS system is limiting wheel spin. See
DIC Warnings and Messages on page 3-58. You may
feel or hear the system working, but this is normal.
If your vehicle is in cruise control when the TCS system
begins to limit wheel spin, the cruise control will
automatically disengage. When road conditions allow you
to safely use it again, you may re-engage the cruise
control. SeeTurn Signal/Multifunction Lever on page 3-6.
4-9

The SERVICE TRACTION
SYSTEM message and
the TCS warning light will
come on to let you
know if there is a problem
with your TCS system.
SeeDIC Warnings
and Messages on
page 3-58.
When this light and the SERVICE TRACTION SYSTEM
message are on, the system will not limit wheel spin.
Adjust your driving accordingly.
The TCS system automatically comes on whenever you
start your vehicle. To limit wheel spin, especially in
slippery road conditions, you should always leave the
system on. But you can turn the TCS system off if
you ever need to.To turn the system off,
press the button located
on the console. You
can turn the system on or
off at any time by
pressing the ACTIVE
HANDLING button. The
DIC will display the
appropriate message when
you push the button.
Active Handling System
The Active Handling System is a computer controlled
system that helps the driver maintain directional control
of the vehicle in difficult driving conditions. This is
accomplished by selectively applying any one of the
vehicle’s brakes.
When you first start your vehicle and begin to drive away
(6 mph (10 km/h)), the message ACT HNDLG WARMING
UP may be displayed in the DIC, the instrument cluster
light will be on, and a chime will sound. This is normal.
You can acknowledge this message by pressing the
RESET button. The Active Handling System performance
is affected until the message, WARM UP COMPLETE, is
displayed in the DIC.
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The ACT HNDLG WARMING UP message may be
displayed in the DIC after exceeding 12 mph (20 km/h)
for 30 seconds. The Active Handling System is off
until the WARM UP COMPLETE message is displayed.
The ACTIVE HANDLING message will come on
when the system is operating. SeeDIC Warnings and
Messages on page 3-58for more information. You
may also feel or hear the system working. This
is normal.
The SERVICE ACTIVE
HNDLG message will be
displayed, the instrument
cluster light will come
on, and a chime will sound
to let you know if there
is a problem with the
system. SeeDIC Warnings
and Messages on
page 3-58for more
information.
When this light and the SERVICE ACTIVE HNDLG
message are on, the system is not operational. Adjust
your driving accordingly.The Active Handling System comes on automatically
whenever you start your vehicle. To help maintain
directional control of the vehicle, you should always
leave the system on. You can turn the system off if you
ever need to. If you turn the Active Handling System
off, the Traction Control System will also be turned off.
Adjust your driving accordingly.
To turn the system off,
press the ACTIVE
HANDLING button on the
console. You can turn
the system on and off at
any time by pressing
the button. The DIC will
display the appropriate
message when you push
the button.
4-11

Competitive Driving Mode
The driver can select this optional handling mode by
pressing the ACTIVE HANDLING button on the console
for more than five seconds. A chime will sound and
COMPETITIVE DRIVING will be displayed in the DIC.
Competitive Driving mode allows the driver to have
full control of the rear wheels while the Active Handling
System helps steer the vehicle by selective brake
application. The instrument cluster light will not be on.
The Traction Control System will not be operating.
Adjust your driving accordingly.
When you press the ACTIVE HANDLING button again,
or turn the ignition to ACC, the Active Handling and
Traction Control Systems will be on. The TRAC/ACT
HNDLG-ON message will be displayed temporarily in the
DIC and a chime will be heard.
Limited-Slip Rear Axle
Your limited-slip rear axle can give you additional
traction on snow, mud, ice, sand or gravel. It works like a
standard axle most of the time, but when one of the rear
wheels has no traction and the other does, this feature
will allow the wheel with traction to move the vehicle.
Selective Ride Control
You may have a ride control system on your vehicle
called Selective Ride Control. The system provides the
following performance benefits:
•Reduced Impact Harshness
•Improved Road Isolation
•Improved High-Speed Stability
•Improved Handling Response
•Better Control of Body Ride Motions
4-12

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.
Magnetic Speed Variable Assist
Steering
Your vehicle is equipped with a steering system that
continuously adjusts the effort you feel when steering at
all vehicle speeds. It provides ease when parking,
yet a firm, solid feel at highway speeds.
Steering Tips
Driving on Curves
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 your 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. SeeTraction Control
System (TCS) on page 4-9.
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 your front
wheels are straight ahead.
Try to adjust your speed so you can “drive” through the
curve. Maintain a reasonable, steady speed. Wait to
accelerate until you are out of the curve, and then
accelerate gently into the straightaway.
4-14

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, your 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.Remember: Any traction control system helps avoid only
the acceleration skid. If your TCS system is off, then
an acceleration skid is also 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 engine braking 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.
Remember: Any anti-lock brake system (ABS) helps
avoid only the braking skid.
4-18

Driving On Snow or Ice
Most of the time, those places where your tires meet
the road probably have good traction.
However, if there is snow or ice between your 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 isabout 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.
Keep your traction control system on. It improves your
ability to accelerate when driving on a slippery road.
Even though your vehicle has the TCS system, you will
want to slow down and adjust your driving to the
road conditions. The Active Handling System may also
activate. SeeTraction Control System (TCS) on
page 4-9andActive Handling System on page 4-10.
Your anti-lock brakes improve your vehicle’s stability
when you make a hard stop on a slippery road.
Even though you have the anti-lock braking system, you
will want to begin stopping sooner than you would on
dry pavement. SeeBraking on page 4-6.
•Allow greater following distance on any slippery road.
•Watch for slippery spots. The road might be fine
until you hit a spot that is covered with ice. On
an otherwise clear road, ice patches may appear in
shaded areas where the sun can not reach:
around clumps of trees, behind buildings or under
bridges. Sometimes the surface of a curve or
an overpass may 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.
4-29

If You Are Stuck: In Sand, Mud,
Ice or Snow
In order to free your vehicle when it is stuck, you will
need to spin the wheels, but you do not want to
spin your wheels too fast. The method known as
“rocking” can help you get out when you are stuck, but
you must use caution.
{CAUTION:
If you let your tires spin at high speed, they can
explode, and you or others could be injured.
And, the transmission or other parts of the
vehicle can overheat. That could cause an
engine compartment re or other damage.
When you are stuck, spin the wheels as little as
possible. Do not spin the wheels above 35 mph
(55 km/h) as shown on the speedometer.
Notice:Spinning your wheels can destroy parts of
your vehicle as well as the tires. If you spin the
wheels too fast while shifting your transmission
back and forth, you can destroy your transmission.
For information about using tire chains on your
vehicle, seeTire Chains on page 5-71.
Rocking Your Vehicle To Get It Out
First, turn your steering wheel left and right. That will
clear the area around your front wheels. You should turn
your TCS System off. SeeTraction Control System
(TCS) on page 4-9. Then shift back and forth between
REVERSE (R) and a forward gear, spinning the
wheels as little as possible. For a manual transmission,
shift slowly between either FIRST (1) or SECOND (2)
and REVERSE (R), allowing the wheels to stop
before shifting into gear. Release the accelerator pedal
while you shift, and press lightly on the accelerator
pedal when the transmission is in gear. By slowly
spinning your wheels in the forward and reverse
directions, you will cause a rocking motion that may free
your vehicle. If that does not get you out after a few
tries, you may need to be towed out. If you do need to
be towed out, seeTowing Your Vehicle on page 4-33.
4-32

Buying New Tires
To find out what kind and size of tires your vehicle
needs, look at the Tire and Loading Information label.
SeeLoading Your Vehicle on page 4-33, for an example
of the label and where it is located on your vehicle.
The tires installed on your vehicle when it was new had
a Tire Performance Criteria Specification (TPC Spec)
number on each tire’s sidewall. When you get new tires,
GM recommends that you get tires with that same
TPC Spec number. That way your vehicle will continue
to have tires that are designed to give proper
endurance, handling, load range, speed rating, traction,
ride, tire pressure monitoring system performance
and other things during normal service on your vehicle.
If your tires have an all-season tread design, the
TPC number will be followed by an “MS” (for mud
and snow).
If you ever replace your tires with those not having a
TPC Spec number, make sure they are the same size,
load range, speed rating and construction type (bias,
bias-belted or radial) as your original tires.{CAUTION:
Mixing tires could cause you to lose control
while driving. If you mix tires of different sizes
(other than those originally installed on your
vehicle) or types (radial and bias-belted tires),
the vehicle may not handle properly, and you
could have a crash. Using tires of different
sizes (other than those originally installed on
your vehicle) may also cause damage to your
vehicle. Be sure to use the correct size and
type tires on all four wheels.
If your vehicle is equipped with Extended Mobility Tires
and you feel that winter tires are needed, see
Extended Mobility Tires (Except Z06) on page 5-61.
{CAUTION:
If you use bias-ply tires on your vehicle, the
wheel rim anges could develop cracks after
many miles of driving. A tire and/or wheel
could fail suddenly, causing a crash. Use only
radial-ply tires with the wheels on your vehicle.
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, 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
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 specified 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 significantly 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 specified 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