2008 CHEVROLET IMPALA Owners Manual

ABS can change the brake pressure faster than any
driver could. The computer is programmed to make the
most of available tire and road conditions. This can
help you steer around the obstacle while braking hard.
As you brake, the computer keeps receiving updates
on wheel speed and controls braking pressure
accordingly.
Remember: ABS 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 the brakes
if that vehicle suddenly slows or stops. Always leave
enough room up ahead to stop, even though you
have ABS.
Using ABS
Do not pump the brakes. Just hold the brake pedal
down rmly and let antilock work for you. You might feel
a slight brake pedal pulsation or notice some noise,
but this is normal.
Braking in Emergencies
At some time, nearly every driver gets into a situation
that requires hard braking.
If you have ABS, you can steer and brake at the same
time. However, if you do not have ABS, your rst
reaction — to hit the brake pedal hard and hold it
down — might 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 ABS, 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
ABS, it is different. SeeAntilock Brake System (ABS)
on page 4-4.
In many emergencies, steering can help you more than
even the very best braking.
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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
4-8

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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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.
Adding non-dealer/non-retailer accessories can affect
your vehicle’s performance. SeeAccessories and
Modifications on page 5-3.
Steering in Emergencies
There are times when steering can be more effective
than braking. For example, you come over a hill and nd
a truck stopped in your lane, or a car suddenly pulls
out from nowhere, or a child darts out from between
parked cars and stops right in front of you. You can
avoid these problems by braking — if you can stop in
time. But sometimes you cannot; there is not room.
That is the time for evasive action — steering around
the problem.
Your vehicle can perform very well in emergencies like
these. First apply the brakes — but, unless you have
antilock brakes, not enough to lock the wheels.
SeeBraking on page 4-3. It is better to remove as
much speed as you can from a possible collision.
Then steer around the problem, to the left or right
depending on the space available.An emergency like this requires close attention and a
quick decision. If you are holding the steering wheel at
the recommended 9 and 3 o’clock positions, you
can turn it a full 180 degrees very quickly without
removing either hand. But you have to act fast, steer
quickly, and just as quickly straighten the wheel
once you have avoided the object.
The fact that such emergency situations are always
possible is a good reason to practice defensive driving
at all times and wear safety belts properly.
4-10

Off-Road Recovery
You may nd that your vehicle’s right wheels have
dropped off the edge of a road onto the shoulder while
you are driving.
If the level of the shoulder is only slightly below the
pavement, recovery should be fairly easy. Ease off the
accelerator and then, if there is nothing in the way,
steer so that your vehicle straddles the edge of
the pavement. You can turn the steering wheel up to
one-quarter turn until the right front tire contacts
the pavement edge. Then turn the steering wheel to go
straight down the roadway.
Passing
Passing another vehicle on a two-lane road can be
dangerous. To reduce the risk of danger while passing,
we suggest the following tips:
Look down the road, to the sides, and to crossroads
for situations that might affect a successful pass.
If in doubt, wait.
Watch for traffic signs, pavement markings, and
lines that could indicate a turn or an intersection.
Never cross a solid or double-solid line on your
side of the lane.
Do not get too close to the vehicle you want to
pass. Doing so can reduce your visibility.
Wait your turn to pass a slow vehicle.
When you are being passed, ease to the right.
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, 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.
4-12