traction control CHEVROLET IMPALA 2009 9.G User Guide

Braking in Emergencies
At some time, nearly every driver gets into a situation
that requires hard braking.
If the vehicle has ABS, it allows the driver to steer and
brake at the same time. However, if the vehicle does
not have ABS, the rst reaction — to hit the brake pedal
hard and hold it down — might be the wrong thing to
do. The wheels can stop rolling. Once they do, the
vehicle cannot respond to the driver’s 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 the driver was trying
to avoid, or into traffic.
If the vehicle does not have ABS, use a “squeeze”
braking technique. This gives maximum braking while
maintaining steering control. 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 helps retain steering control. With ABS, it is
different. SeeAntilock Brake System (ABS) on page 4-5.
In many emergencies, steering can help more than
even the very best braking.
Electronic Stability Control (ESC)
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 3-42.
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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. See
DIC Warnings and Messages on page 3-49.
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 3-9.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 4-19.
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
requires service.
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If the problem does not clear after restarting the vehicle,
you should see your dealer/retailer for service. See
DIC Warnings and Messages on page 3-49for more
information.
Adding non-dealer/non-retailer accessories can affect
your vehicle’s performance. SeeAccessories and
Modifications on page 5-3for more information.
Traction Control System (TCS)
The 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.
The system may be heard or felt while it is working, but
this is normal.If cruise control is being used when TCS begins to limit
wheel spin, the cruise control will automatically
disengage. Cruise control may be reengaged when road
conditions allow. SeeCruise Control on page 3-9.
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 2-24.
When the system is on,
this warning light comes
on and stays on 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 3-49for more information.
To limit wheel spin, especially in slippery road
conditions, TCS should always be left on. But the
system can be turned off if needed.
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Turn the system off if the vehicle gets stuck in sand,
mud or snow and rocking the vehicle is required.
SeeRocking Your Vehicle to Get It Out on page 4-20
andIf Your Vehicle is Stuck in Sand, Mud, Ice, or Snow
on page 4-19for more information.
To turn the system on or
off, press the Traction
Control button located on
the instrument panel.
When the system is turned off, the traction control
warning light comes on and TRACTION CONTROL OFF
appears on the DIC. If the traction control system is
limiting wheel spin when the button is pressed to turn the
system off, the warning light comes 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
the vehicle’s performance. SeeAccessories and
Modifications on page 5-3for more information.Steering
Power Steering
If power steering assist is lost because the engine stops
or the system is not functioning, the vehicle can be
steered but it will take more effort.
Steering Tips
It is important to take curves at a reasonable speed.
Traction in a curve depends on the condition of the tires
and the road surface, the angle at which the curve is
banked, and vehicle speed. While in a curve, speed is
the one factor that can be controlled.
If there is a need to reduce speed, do it before entering
the curve, while the front wheels are straight.
Try to adjust the speed so you can drive through the
curve. Maintain a reasonable, steady speed. Wait
to accelerate until out of the curve, and then accelerate
gently into the straightaway.
4-9

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 the 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.
If the 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,
the 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, 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
the 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 the vehicle has the Antilock Brake System (ABS),
remember: It helps avoid only the braking skid. If
the vehicle does 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 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 crashes. 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.
Hydroplaning
Hydroplaning is dangerous. Water can build up under
your vehicle’s tires so they actually ride on the
water. This can happen if the road is wet enough and
you are going fast enough. When your vehicle is
hydroplaning, it has little or no contact with the road.
There is no hard and fast rule about hydroplaning. The
best advice is to slow down when the road is wet.
Other Rainy Weather Tips
Besides slowing down, other wet weather driving tips
include:
Allow extra following distance.
Pass with caution.
Keep windshield wiping equipment in good shape.
Keep the windshield washer uid reservoir lled.
Have good tires with proper tread depth. SeeTires
on page 5-53.
Turn off cruise control.
4-14

Winter Driving
Driving on Snow or Ice
Drive carefully when there is snow or ice between the
tires and the road, creating less traction or grip. Wet ice
can occur at about 32°F (0°C) when freezing rain
begins to fall, resulting in even less traction. Avoid
driving on wet ice or in freezing rain until roads can be
treated with salt or sand.
Drive with caution, whatever the condition. Accelerate
gently so traction is not lost. Accelerating too quickly
causes the wheels to spin and makes the surface under
the tires slick, so there is even less traction.
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.If the vehicle has theTraction Control System (TCS) on
page 4-8, it improves the ability to accelerate on
slippery roads, but slow down and adjust your driving to
the road conditions. When driving through deep snow,
turn off the traction control system to help maintain
vehicle motion at lower speeds.
TheAntilock Brake System (ABS) on page 4-5improves
vehicle stability during hard stops on a slippery roads,
but apply the brakes sooner than when on dry
pavement.
Allow greater following distance on any slippery road
and watch for slippery spots. Icy patches can occur on
otherwise clear roads in shaded areas. The surface
of a curve or an overpass can remain icy when
the surrounding roads are clear. Avoid sudden steering
maneuvers and braking while on ice.
Turn off cruise control, if equipped, on slippery surfaces.
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Rocking Your Vehicle to Get It Out
Turn the steering wheel left and right to clear the
area around the front wheels. Turn off any traction
system. Shift back and forth between R (Reverse) 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 shifting, and press lightly on the accelerator
pedal when the transmission is in gear. Slowly
spinning the wheels in the forward and reverse
directions causes a rocking motion that could free the
vehicle. If that does not get the vehicle out after a
few tries, it might need to be towed out. If the vehicle
does need to be towed out, seeTowing Your Vehicle on
page 4-26.
Loading the 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 the 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 the
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 the vehicle.
4-20

Service
For service and parts needs, visit your dealer/retailer.
You will receive genuine GM parts and GM-trained and
supported service people.
Genuine GM parts have one of these marks:
Accessories and Modications
When non-dealer/non-retailer accessories are added to
the vehicle, they can affect vehicle 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 the vehicle warranty.
Damage to vehicle components resulting from the
installation or use of non-GM certied parts, including
control module modications, are not covered under the
terms of the vehicle warranty and may affect remaining
warranty coverage for affected parts.
GM Accessories are designed to complement and
function with other systems on the vehicle. Your GM
dealer/retailer can accessorize the 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 1-72.
5-3

You need new tires if any of the following statements
are true:
You can see the indicators at three or more places
around the tire.
You can see cord or fabric showing through the
tire’s rubber.
The tread or sidewall is cracked, cut, or snagged
deep enough to show cord or fabric.
The tire has a bump, bulge, or split.
The tire has a puncture, cut, or other damage that
cannot be repaired well because of the size or
location of the damage.
The rubber in tires degrades over time, even if they are
not being used. This is also true for the spare tire, if
your vehicle has one. Multiple conditions affect how fast
this aging takes place, including temperatures, loading
conditions, and ination pressure maintenance. With
proper care and maintenance tires will typically wear out
before they degrade due to age. If you are unsure
about the need to replace your tires as they get older,
consult the tire manufacturer for more information.
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 5-54for additional
information.
5-69