2002 CHEVROLET AVALANCHE traction control

4-21 Scanning the Terrain
Off-road driving can take you over many different kinds
of terrain. You need to be familiar with the terrain and its
many different features. Here are some things to consider.
Surface Conditions. Off
-roading can take you over
hard
-packed dirt, gravel, rocks, grass, sand, mud,
snow or ice. Each of these surfaces affects the steering,
acceleration and braking of your vehicle in different
ways. Depending upon the kind of surface you are on,
you may experience slipping, sliding, wheel spinning,
delayed acceleration, poor traction and longer
braking distances.
Surface Obstacles. Unseen or hidden obstacles can be
hazardous. A rock, log, hole, rut or bump can startle you
if you're not prepared for them. Often these obstacles
are hidden by grass, bushes, snow or even the rise
and fall of the terrain itself. Here are some things
to consider:

Is the path ahead clear?

Will the surface texture change abruptly up ahead?

Does the travel take you uphill or downhill?
(There's more discussion of these subjects later.)

Will you have to stop suddenly or change
direction quickly?When you drive over obstacles or rough terrain, keep a
firm grip on the steering wheel. Ruts, troughs or other
surface features can jerk the wheel out of your hands if
you're not prepared.
When you drive over bumps, rocks, or other obstacles,
your wheels can leave the ground. If this happens, even
with one or two wheels, you can't control the vehicle as
well or at all.
Because you will be on an unpaved surface, it's
especially important to avoid sudden acceleration,
sudden turns or sudden braking.
In a way, off
-road driving requires a different kind of
alertness from driving on paved roads and highways.
There are no road signs, posted speed limits or signal
lights. You have to use your own good judgment about
what is safe and what isn't.
Drinking and driving can be very dangerous on any
road. And this is certainly true for off
-road driving.
At the very time you need special alertness and driving
skills, your reflexes, perceptions and judgment can be
affected by even a small amount of alcohol. You could
have a serious
-- or even fatal -- accident if you drink
and drive or ride with a driver who has been drinking.
See ªDrunken Drivingº in the Index.

4-22 Driving on Off-Road Hills
Off-road driving often takes you up, down or across a
hill. Driving safely on hills requires good judgment and
an understanding of what your vehicle can and can't do.
There are some hills that simply can't be driven,
no matter how well built the vehicle.
CAUTION:
Many hills are simply too steep for any vehicle.
If you drive up them, you will stall. If you drive
down them, you can't control your speed. If you
drive across them, you will roll over. You could be
seriously injured or killed. If you have any doubt
about the steepness, don't drive the hill.
Approaching a Hill
When you approach a hill, you need to decide if it's one
of those hills that's just too steep to climb, descend or
cross. Steepness can be hard to judge. On a very small
hill, for example, there may be a smooth, constant
incline with only a small change in elevation where you
can easily see all the way to the top.On a large hill, the incline may get steeper as you near
the top, but you may not see this because the crest of the
hill is hidden by bushes, grass or shrubs.
Here are some other things to consider as you approach
a hill.

Is there a constant incline, or does the hill get sharply
steeper in places?

Is there good traction on the hillside, or will the
surface cause tire slipping?

Is there a straight path up or down the hill so you
won't have to make turning maneuvers?

Are there obstructions on the hill that can block your
path (boulders, trees, logs or ruts)?

What's beyond the hill? Is there a cliff, an
embankment, a drop
-off, a fence? Get out and
walk the hill if you don't know. It's the smart way
to find out.

Is the hill simply too rough? Steep hills often have
ruts, gullies, troughs and exposed rocks because they
are more susceptible to the effects of erosion.

4-30 Driving in Mud, Sand, Snow or Ice
When you drive in mud, snow or sand, your wheels
won't get good traction. You can't accelerate as
quickly, turning is more difficult, and you'll need
longer braking distances.
It's best to use a low gear when you're in mud
-- the
deeper the mud, the lower the gear. In really deep mud,
the idea is to keep your vehicle moving so you don't
get stuck.
When you drive on sand, you'll sense a change in wheel
traction. But it will depend upon how loosely packed the
sand is. On loosely packed sand (as on beaches or sand
dunes) your tires will tend to sink into the sand. This has
an effect on steering, accelerating and braking. You may
want to reduce the air pressure in your tires slightly
when driving on sand. This will improve traction.Hard packed snow and ice offer the worst tire traction.
On these surfaces, it's very easy to lose control. On wet
ice, for example, the traction is so poor that you will
have difficulty accelerating. And if you do get moving,
poor steering and difficult braking can cause you to slide
out of control.
CAUTION:
Driving on frozen lakes, ponds or rivers can be
dangerous. Underwater springs, currents under
the ice, or sudden thaws can weaken the ice.
Your vehicle could fall through the ice and you
and your passengers could drown. Drive your
vehicle on safe surfaces only.

6-48 Buying New Tires
To find out what kind and size of tires you need,
look at the Certification/Tire label.
The tires installed on your vehicle when it was new had
a Tire Performance Criteria Specification (TPC Spec)
number on each tire's sidewall. When you get new tires,
get ones 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,
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
ªMSº (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.
CAUTION: (Continued)
CAUTION: (Continued)
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.
If your vehicle has 17 inch road tires (those
originally installed on your vehicle) it is all
right to drive with the 16 inch spare tire that
came with your vehicle. When new, your vehicle
included a spare tire and wheel assembly with the
same overall diameter as your vehicle's road tires
and wheels. Because this spare tire was developed
for use on your vehicle, it will not affect vehicle
handling or cause damage to your vehicle.
CAUTION:
If you use bias-ply tires on your vehicle, the
wheel rim flanges 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.

6-49 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 specified government test course.
For example, a tire graded 150 would wear one and
a half (1 1/2) 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 significantly 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 specified 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.

6-52 Tire Chains
CAUTION:
If your vehicle is a 1500 Series, don't use tire
chains. They can damage your vehicle because
there's not enough clearance. Tire chains used on a
vehicle without the proper amount of clearance can
cause damage to the brakes, suspension or other
vehicle parts. The area damaged by the tire chains
could cause you to lose control of your vehicle and
you or others may be injured in a crash.
Use another type of traction device only if its
manufacturer recommends it for use on your vehicle
and tire size combination and road conditions.
Follow that manufacturer's instructions. To help
avoid damage to your vehicle, drive slowly, readjust
or remove the device if it's contacting your vehicle,
and don't spin your wheels.
If you do find traction devices that will fit,
install them on the rear tires.
NOTICE:
If your vehicle is a 2500 Series, use tire chains
only where legal and only when you must.
Use chains that are the proper size for your
tires. Install them on the tires of the rear axle.
Don't use chains on tires of the front axle.
Tighten them as tightly as possible with the
ends securely fastened. Drive slowly and follow
the chain manufacturer's instructions. If you
can hear the chains contacting your vehicle,
stop and retighten them. If the contact continues,
slow down until it stops. Driving too fast or
spinning the wheels with chains on will damage
your vehicle.