traction control CHEVROLET IMPALA 2005 8.G User Guide

Your Driving, the Road, and Your Vehicle..........4-2
Defensive Driving...........................................4-2
Drunken Driving.............................................4-3
Control of a Vehicle........................................4-6
Braking.........................................................4-6
Anti-Lock Brake System (ABS).........................4-7
Braking in Emergencies...................................4-9
Traction Control System (TCS).........................4-9
Steering......................................................4-11
Off-Road Recovery.......................................4-13
Passing.......................................................4-13
Loss of Control.............................................4-15
Driving at Night............................................4-16
Driving in Rain and on Wet Roads..................4-18City Driving..................................................4-20
Freeway Driving...........................................4-21
Before Leaving on a Long Trip.......................4-22
Highway Hypnosis........................................4-23
Hill and Mountain Roads................................4-23
Winter Driving..............................................4-25
If Your Vehicle is Stuck in Sand, Mud,
Ice or Snow..............................................4-29
Rocking Your Vehicle to Get It Out.................4-30
Loading Your Vehicle....................................4-30
Towing..........................................................4-35
Towing Your Vehicle.....................................4-35
Recreational Vehicle Towing...........................4-35
Towing a Trailer...........................................4-37
Section 4 Driving Your Vehicle
4-1

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 are driving on snow or ice,
it is easy to ask more of those control systems than the
tires and road can provide. That means you can lose
control of your vehicle. SeeTraction Control System
(TCS) on page 4-9.
Braking
Braking action involves perception time and reaction time.
First, you have to decide to push on the brake pedal.
That is perception time. Then you have to bring up your
foot and do it. That is reaction time.
Average reaction time is about three-fourths of a
second. But that is only an average. It might be less
with one driver and as long as two or three seconds or
more with another. Age, physical condition, alertness,
coordination, and eyesight all play a part. So do alcohol,
drugs, and frustration. But even in three-fourths of a
second, a vehicle moving at 60 mph (100 km/h) travels66 feet (20 m). That could be a lot of distance in an
emergency, so keeping enough space between
your vehicle and others is important.
And, of course, actual stopping distances vary greatly
with the surface of the road, whether it is pavement
or gravel; the condition of the road, whether it is
wet, dry, or icy; tire tread; the condition of your brakes;
the weight of the vehicle; and the amount of brake
force applied.
Avoid needless heavy braking. Some people drive
in spurts — heavy acceleration followed by heavy
braking — rather than keeping pace with traffic. This is
a mistake. Your brakes may not have time to cool
between hard stops. Your brakes will wear out much
faster if you do a lot of heavy braking. If you keep pace
with the traffic and allow realistic following distances,
you will eliminate a lot of unnecessary braking.
That means better braking and longer brake life.
If your engine ever stops while you are driving, brake
normally but do not pump your brakes. If you do,
the pedal may get harder to push down. If your engine
stops, you will still have some power brake assist.
But you will use it when you brake. Once the power
assist is used up, it may take longer to stop and
the brake pedal will be harder to push.
4-6

Braking in Emergencies
At some time, nearly every driver gets into a situation
that requires hard braking.
If you have anti-lock brakes, you can steer and brake at
the same time. However, if you do not have anti-lock
brakes, your rst reaction — to hit the brake pedal hard
and hold it down — may be the wrong thing to do.
Your wheels can stop rolling. Once they do, the vehicle
cannot respond to your steering. Momentum will
carry it in whatever direction it was headed when the
wheels stopped rolling. That could be off the road, into
the very thing you were trying to avoid, or into traffic.
If you do not have anti-lock brakes, use a “squeeze”
braking technique. This will give you maximum braking
while maintaining steering control. You can do this
by pushing on the brake pedal with steadily increasing
pressure.
In an emergency, you will probably want to squeeze the
brakes hard without locking the wheels. If you hear or
feel the wheels sliding, ease off the brake pedal.
This will help you retain steering control. If you do have
anti-lock brakes, it is different. SeeAnti-Lock Brake
System (ABS) on page 4-7.
In many emergencies, steering can help you more than
even the very best braking.
Traction Control System (TCS)
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. SeeTraction Active
Message on page 3-41.
You may feel or hear the system working, but this is
normal.United States
Canada
4-9

If your vehicle is in cruise control when the traction
control 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. SeeCruise Control
on page 3-11.
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. SeeAutomatic Transaxle Operation
on page 2-20.
When the system is on,
this warning light will
come on to let you know
if there’s a problem.
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. SeeRocking Your Vehicle to Get It Out on
page 4-30andIf Your Vehicle is Stuck in Sand, Mud, Ice
or Snow on page 4-29for more information.
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 light should go off.
4-10

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 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 apply the brakes. Both control
systems — steering and braking — have to do their work
where the tires meet the road. Unless you have
four-wheel anti-lock 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 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.
4-11

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 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 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.
If you have the anti-lock braking 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.
4-15

Driving in Rain and on Wet Roads
Rain and wet roads can mean driving trouble. On a wet
road, you cannot stop, accelerate, or turn as well
because your tire-to-road traction is not as good as on
dry roads. And, if your tires do not have much tread
left, you will 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 your
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 your windshield wiping equipment in
good shape and keep your windshield washer tank lled
with washer uid. Replace your 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.
Driving too fast through large water puddles or even going
through some car washes can cause problems, too.
The water may affect your brakes. Try to avoid puddles.
But if you cannot, try to slow down before you hit them.
{CAUTION:
Wet brakes can cause accidents. They will 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 your brake pedal lightly
until your brakes work normally.
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 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.
Traction control improves your ability to accelerate when
driving on a slippery road. Even though your vehicle
has a traction control system, you will want to slow down
and adjust your driving to the road conditions. Under
certain conditions, you may want to turn the traction
control system 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 4-9.
Unless you have the anti-lock braking system (ABS),
you will want to brake very gently, too. If you do
have ABS, seeAnti-Lock Brake System (ABS) on
page 4-7. ABS improves your vehicle’s stability
when you make a hard stop on a slippery road.
Whether you have ABS or not, you will want to begin
stopping sooner than you would on dry pavement.
4-26

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 your traction
control 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. 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
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 4-35.
Loading Your Vehicle
It is very important to know how much weight your
vehicle can carry. Two labels on your vehicle show
how much weight it may properly carry, the Tire
and Loading Information label and the Vehicle
Certication 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.
4-30

Buying New Tires
To nd out what kind and size of tires your vehicle
needs, look at the tire and loading information label.
For more information about this label and its location on
your vehicle, seeLoading Your Vehicle on page 4-30.
The tires installed on your vehicle when it was new had
a Tire Performance Criteria Specication (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, speed rating, load range,
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 “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
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. SeeCompact Spare
Tire on page 5-88.
{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.
5-72