2005 CHEVROLET EXPRESS CARGO VAN traction control

Cruise Control
If your vehicle has cruise control, you can maintain a
speed of about 25 mph (40 km/h) or more without
keeping your foot on the accelerator. This can really
help on long trips. Cruise control does not work at
speeds below about 25 mph (40 km/h).
If you apply your brakes, the cruise control will
disengage.
{CAUTION:
Cruise control can be dangerous where you
cannot drive safely at a steady speed. So, do
not use your cruise control on winding roads
or in heavy traffic.
Cruise control can be dangerous on slippery
roads. On such roads, fast changes in tire
traction can cause needless wheel spinning,
and you could lose control. Do not use cruise
control on slippery roads.
9(Off):This position turns the system off.
R(On):This position activates the system.
S(Resume/Accelerate):Push the lever to this symbol
to make the vehicle accelerate or resume to a
previously set speed.
T(Set):Press this button to set the speed.
3-10

Remember: Anti-lock 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
your brakes if that vehicle suddenly slows or stops.
Always leave enough room up ahead to stop, even
though you have anti-lock brakes.
Using Anti-Lock
Do not pump the brakes. Just hold the brake pedal
down rmly and let anti-lock work for you. You may feel
the brakes vibrate, or you may notice some noise,
but this is normal.
Braking in Emergencies
With anti-lock brakes, 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 rst 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.
The following chart describes the StabiliTrak
®not
ready light and the StabiliTrak®indicator light.
4-8

StabiliTrak®Not Ready Light StabiliTrak®Indicator Light Meaning
Off OffStabiliTrak®is enabled, but not
active.
The traction control is not active.
Off FlashingStabiliTrak
®is active, or the traction
control is active.
Off OnStabiliTrak
®is disabled due to
system fault. When on after
restarting, the vehicle needs to be
serviced.
On OffStabiliTrak
®is disabled due to
system initialization or the driver has
disabled with switch.
On FlashingStabiliTrak
®is not initialized and not
disabled.
The traction control is active.
For more information, seeStabiliTrak
®Not Ready Light
on page 3-33andStabiliTrak®Indicator Light on
page 3-33.Pressing and holding the
StabiliTrak®button located
on the instrument panel
for more than ve seconds
can turn off StabiliTrak
®
and part of the traction
control system.
4-9

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 4-30.
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 ash, 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 3-10.
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 for service.
4-10

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.
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.
4-11

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.
Remember: Any anti-lock brake system (ABS) helps
avoid only the braking skid.Driving at Night
Night driving is more dangerous than day driving. One
reason is that some drivers are likely to be impaired — by
alcohol or drugs, with night vision problems, or by fatigue.
Here are some tips on night driving.
Drive defensively.
Do not drink and drive.
Adjust your inside rearview mirror to reduce the
glare from headlamps behind you.
4-16

Buying New Tires
To nd out what kind and size of tires you need, look at
the Certication/Tire label or the Tire and Loading
Information label. For examples of these labels and their
location on your vehicle, seeLoading Your Vehicle on
page 4-31.
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,
General Motors 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 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.
{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.
5-65

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 specied 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 signicantly 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 specied 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.
5-66