2003 CHEVROLET IMPALA traction control

{CAUTION:
Drinking and then driving is very dangerous.
Your re¯exes, perceptions, attentiveness
and judgment can be affected by even a
small amount of alcohol. You can have a
serious Ð or even fatal Ð collision if you drive
after drinking. Please don't drink and drive or
ride with a driver who has been drinking. Ride
home in a cab; or if you're with a group,
designate a driver who will not drink.
Control of a Vehicle
You have three systems that make your vehicle go
where you want it to go. They are the brakes, the
steering and the accelerator. All three systems have to do
their work at the places where the tires meet the road.
Sometimes, as when you're driving on snow or ice, it's
easy to ask more of those control systems than the
tires and road can provide. That means you can lose
control of your vehicle. Also see
Traction Control System
(TCS) (3800 V6 Engine) on page 4-9.
4-5

Traction Control System (TCS)
(3800 V6 Engine)
Your vehicle may have a traction control system 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 transaxle and
apply the front brakes to limit wheel spin.
This light will come on when your traction control
system is limiting wheel spin. See
Traction Active
Message on page 3-41.
You may feel or hear the system working, but this is
normal.
If your vehicle is in cruise control when the traction
control system begins to limit wheel spin, the cruise
control will automatically disengage. When roadconditions allow you to safely use it again, you may
re-engage the cruise control. See ªCruise Controlº
in
Turn Signal/Multifunction Lever on page 3-7.
The traction control system operates in all transaxle
shift lever positions. But the system can upshift
the transaxle only as high as the shift lever position
you've chosen, so you should use the lower gears only
when necessary. See
Automatic Transaxle Operation
on page 2-23.
When the system is on,
this warning light will come
on to let you know if
there's a problem.
See. When this warning light is on, the system will not
limit wheel spin. Adjust your driving accordingly.
To limit wheel spin, especially in slippery road conditions,
you should always leave the traction control system on.
But you can turn the system off if you ever need to. You
should turn the system off if your vehicle ever gets stuck
in sand, mud or snow and rocking the vehicle is required.
See ªRocking Your Vehicle To Get It Outº under
If You
Are Stuck: In Sand, Mud, Ice or Snow on page 4-30. United States
Canada
4-9

To turn the system on or
off, press the TRAC OFF
button on the left side
of the instrument panel.
When you turn the system off, a chime will sound and
the TRAC OFF warning light will come on and stay on.
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.
You can turn the system back on at any time by
pressing the button again. The TRAC OFF warning light
should go off.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
Driving on Curves
It's important to take curves at a reasonable speed.
A lot of the ªdriver lost controlº accidents mentioned on
the news happen on curves.
Here's 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's no traction, inertia
will keep the vehicle going in the same direction. If
you've ever tried to steer a vehicle on wet ice, you'll
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're in a curve, speed is the one factor you
can control.
4-10

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
ªoverdrivingº 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
aren't 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'll
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 Ð such as enough water, ice or packed snow
on the road to make a ªmirrored surfaceº Ð and slow
down when you have any doubt.
If you have the anti-lock braking system, remember: It
helps avoid only the braking skid. If you do not have
anti-lock, 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.
4-15

What's the worst time for this? ªWet ice.º 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's
about freezing (32ÉF; 0ÉC) 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 a traction control system,
you'll want to slow down and adjust your driving to
the road conditions. See
Traction Control System (TCS)
(3800 V6 Engine) on page 4-9.
Unless you have the anti-lock braking system, you'll
want to brake very gently, too. (If you do have anti-lock,
see
Braking on page 4-6. This system improves your
vehicle's stability when you make a hard stop on a
slippery road.) Whether you have the anti-lock braking
system or not, you'll want to begin stopping sooner than
you would on dry pavement. Without anti-lock brakes,
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 you have anti-lock, if you brake
so hard that your wheels stop rolling, you'll just slide.
Brake so your wheels always keep rolling and you can
still steer.
·Whatever your 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's covered with ice. On
an otherwise clear road, ice patches may appear in
shaded areas where the sun can't 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're actually on the ice, and avoid sudden
steering maneuvers.
4-27

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 don't want to spin your
wheels too fast. The method known as ªrockingº can
help you get out when you're 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 transaxle or other parts of the
vehicle can overheat. That could cause an
engine compartment ®re or other damage.
When you're stuck, spin the wheels as little as
possible. Don't 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 transaxle back
and forth, you can destroy your transaxle. See
ªRocking Your Vehicle To Get It Out.º
For information about using tire chains on your vehicle,
see
Tire 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. If your vehicle
has traction control, you should turn the system off.
See
Traction Control System (TCS) (3800 V6 Engine)
on page 4-9. Then shift back and forth between
REVERSE (R) and a forward gear, spinning the wheels
as little as possible. Release the accelerator pedal
while you shift, and press lightly on the accelerator pedal
when the transaxle 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 doesn't get you out after a few tries, you may
need to be towed out. If you do need to be towed out,
see ªTowing Your Vehicleº following.
4-30

Buying New Tires
To ®nd out what kind and size of tires you need, look at
the Tire-Loading Information label.
The tires installed on your vehicle when it was new had
a Tire Performance Criteria Speci®cation (TPC Spec)
number on each tire's sidewall. When you get new tires,
get ones with that same TPC Spec number. That way
your vehicle will continue to have tires that are designed
to give proper endurance, handling, speed rating,
traction, ride 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 ªMSº (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
or types (radial and bias-belted tires), the
vehicle may not handle properly, and you
could have a crash. Using tires of different
sizes may also cause damage to your vehicle.
Be sure to use the same size and type tires on
all wheels. It's all right to drive with your
compact spare temporarily, it was developed
for use on your vehicle. See ªCompact Spare
Tireº in the index.
{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.
5-67

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 speci®ed 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 signi®cantly 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 speci®ed 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.
5-68