wheel CHEVROLET EXPRESS CARGO VAN 2007 1.G Owner's Manual

Let us say the road is wet and you are driving
safely. Suddenly, an animal jumps out in front of
you. You slam on the brakes and continue braking.
Here is what happens with ABS:
A computer senses that wheels are slowing down.
If one of the wheels is about to stop rolling, the
computer will separately work the brakes at each
front wheel and at both rear wheels.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.
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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 firmly and let anti-lock work for you.
You might feel the brakes vibrate or notice
some noise, but this is normal.
Braking in Emergencies
With ABS, you can steer and brake at the same
time. In many emergencies, steering can help you
more than even the very best braking.
Locking Rear Axle
If your vehicle has this feature, your locking 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.
StabiliTrak®System
If your vehicle has StabiliTrak®, it combines
anti-lock brake, traction and stability control
systems and helps the driver maintain directional
control of the vehicle in most driving conditions.
When you first start your vehicle and begin to drive
away, the system performs several diagnostic
checks to ensure that it is working properly. 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). In some cases,
it may take approximately 2 miles (3.2 km) of driving
before the system initializes.
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Pressing and holding
the StabiliTrak®button
located on the
instrument panel for
more than five seconds
can turn off StabiliTrak
®
and part of the
traction control system.
For your safety, the system can only be disabled
when the vehicle speed is less than 20 mph
(32 km/h). You will hear three chimes and the
StabiliTrak
®not ready light will come on.
To turn on the StabiliTrak
®system, press the
StabiliTrak®button again. StabiliTrak®will
automatically turn back on when the vehicle speed
exceeds 20 mph (32 km/h). You will hear one chime
and the StabiliTrak
®not ready light will turn off.
When the StabiliTrak
®system has been turned off
you may still hear system noises as a result of
the brake-traction control coming on.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. SeeIf Your Vehicle is
Stuck in Sand, Mud, Ice, or Snow on page 260.
StabiliTrak®System Operation
The StabiliTrak®system is normally on, except
when the system is initializing or has been disabled
with the StabiliTrak
®button. The StabiliTrak®
system will automatically activate to assist the
driver in maintaining vehicle directional control in
most driving conditions. When activated, the
StabiliTrak
®system may reduce engine power to
the wheels and apply braking to individual wheels
as necessary to assist the driver with vehicle
directional control. If your vehicle is in cruise control
when the system activates, the StabiliTrak
®
indicator light on the instrument panel will flash, and
the cruise control will automatically disengage.
When the StabiliTrak
®system is no longer active,
you may re-engage the cruise control. SeeCruise
Control on page 151.
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The StabiliTrak®system may also turn off
automatically if it determines that a problem exists
with the system. If the problem does not clear
itself after restarting the vehicle, you should see
your dealer/retailer for service.
Traction Control Operation
The traction control system is part of the
StabiliTrak®system. Traction control limits wheel
spin by reducing engine power to the wheels
(engine speed management) and by applying
brakes to each individual wheel (brake-traction
control) as necessary.
If the brake-traction control system activates
constantly or if the brakes have heated up due to
high speed braking, the brake-traction control
will be automatically disabled. The system
will come back on after the brakes have cooled.
This can take up to two minutes or longer
depending on brake usage.The traction control system may activate on dry or
rough roads or under conditions such as heavy
acceleration while turning or abrupt upshifts/
downshifts of the transmission. When this happens
you may notice a reduction in acceleration, or
may hear a noise or vibration. This is normal.
Adding non-dealer/non-retailer accessories
can affect your vehicle’s performance. See
Accessories and Modications on page 290for
more information.
All-Wheel Drive (AWD) System
If your vehicle has all-wheel drive, your engine’s
driving power is sent to all four wheels for
extra traction when needed.
This is like four-wheel drive, but there is no
separate lever or switch to engage or disengage
the front axle. It is fully automatic, and adjusts itself
as needed for road conditions.
You may experience a brief vehicle vibration upon
acceleration when driving in slippery conditions.
This is normal and is an indication that the
all-wheel drive system is functioning properly.
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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 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.
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
the 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.
Adding non-dealer/non-retailer accessories can
affect your vehicle’s performance. SeeAccessories
and Modications on page 290.
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Steering in Emergencies
There are times when steering can be more
effective than braking. For example, you come
over a hill and find 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. SeeBraking
on page 232. 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.
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Off-Road Recovery
You may find that your 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
The driver of a vehicle about to pass another on a
two-lane highway waits for just the right moment,
accelerates, moves around the vehicle ahead,
then goes back into the right lane again. A simple
maneuver?
Not necessarily! Passing another vehicle on a
two-lane highway is a potentially dangerous move,
since the passing vehicle occupies the same
lane as oncoming traffic for several seconds.
A miscalculation, an error in judgment, or a brief
surrender to frustration or anger can suddenly
put the passing driver face to face with the worst
of all traffic accidents — the head-on collision.
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•Try not to pass more than one vehicle at a time
on two-lane roads. Reconsider before passing
the next vehicle.
•Do not overtake a slowly moving vehicle too
rapidly. Even though the brake lamps are not
flashing, it might be slowing down or starting
to turn.
•If you are being passed, make it easy for the
following driver to get ahead of you. Perhaps
you can ease a little to the right.
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 is 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.
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Highway Hypnosis
Is there actually such a condition as highway
hypnosis? Or is it just plain falling asleep at the
wheel? Call it highway hypnosis, lack of
awareness, or whatever.
There is something about an easy stretch of road
with the same scenery, along with the hum of
the tires on the road, the drone of the engine,
and the rush of the wind against the vehicle that
can make you sleepy. Do not let it happen to you!
If it does, your vehicle can leave the road in
less than a second, and you could crash and be
injured.
What can you do about highway hypnosis?
First, be aware that it can happen.Then here are some tips:•Make sure your vehicle is well ventilated, with
a comfortably cool interior.
•Keep your eyes moving. Scan the road ahead
and to the sides. Check your vehicle’s mirrors
and instruments frequently.
•If you get sleepy, pull off the road into a rest,
service, or parking area and take a nap, get
some exercise, or both. For safety, treat
drowsiness on the highway as an emergency.
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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.Accelerate gently. 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.
The Anti-Lock Brake System (ABS) improves your
vehicle’s stability when you make a hard stop
on a slippery road. Even though you have ABS,
you will want to begin stopping sooner than
you would on dry pavement. SeeAnti-Lock Brake
System (ABS) on page 233.
•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 cannot
reach, such as 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.
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