wheel GMC YUKON 2002 Owner's Guide

4-10
The Traction Assist System may operate on dry roads
under some conditions. When this happens, you may
notice a reduction in acceleration. This is normal and
doesn't mean there's a problem with your vehicle.
Examples of these conditions include a hard acceleration
in a turn, an abrupt upshift or downshift of the
transmission or driving on rough roads.
If your vehicle is in cruise control when the TAS begins
to limit wheel spin, the cruise control will automatically
disengage. When road conditions allow you to safely
use it again, you may re
-engage the cruise control. See
ªCruise Controlº in the Index.
When the TRACTION
OFF light is on, the TAS
is off and will not limit
wheel spin. Adjust your
driving accordingly.The TRACTION OFF light will come on under the
following conditions:

The Traction Assist System is turned off, either by
pressing the TAS on/off button or turning off the
automatic engagement feature of the TAS.

The transmission is in FIRST (1); TAS will not
operate in this gear. This is normal.

The vehicle is driven on an extremely rough road.
When the vehicle leaves the rough surface, slows
down or stops, the light will go off and TAS will be
on again. This is normal.

A Traction Assist System, Anti-Lock Brake System
or engine
-related problem has been detected and the
vehicle needs service.
See ªTraction Off Lightº in the Index.

4-11
The Traction Assist System, as delivered from the
factory, will automatically come on whenever you start
your vehicle. To limit wheel spin, especially in slippery
road conditions, you should always leave the system on.
But you can turn the TAS off if you ever need to. You
should turn the TAS off if your vehicle ever gets stuck in
sand, mud or snow and rocking the vehicle is required.
See ªRocking Your Vehicleº in the Index.
To turn the system on
or off press the TAS
on/off button located
to the left of the
steering wheel on the
instrument panel.If you used the button to turn the system off, the
TRACTION OFF light will come on and stay on.
You can turn the system back on at any time by
pressing the button again. The TRACTION OFF
light should go off.
If desired, you can change the TAS automatic
engagement feature so that the system will not come on
automatically when the engine is started. To do so:
1. Park the vehicle with the ignition off and the
transmission in PARK (P).
2. Turn the ignition to RUN; do not start the engine.
3. Apply the brake pedal, press the accelerator pedal to
the floor and then press the TAS on/off button and
hold it down for at least six seconds.
4. Release the TAS button and both pedals.
5. Turn off the ignition and wait a few seconds.
The next time you start your vehicle, the TAS will not
automatically come on. You can restore the automatic
feature by using the same procedure. Whether the TAS is
set to come on automatically or not, you can always turn
the system on or off by pressing the TAS on/off button.

4-12
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.
Speed-Sensitive Steering (If Equipped)
This system varies the amount of steering effort
proportionate to your vehicle speed. Steering is easier at
lower speeds for maneuvering and parking ease. As
your vehicle speed increases, the steering effort also
increases. At highway speeds, the amount of steering
effort is increased.
Steering Tips
Driving on Curves
It's important to take curves at a reasonable speed.
A lot of the ªdriver lost controlº accidents mentioned on
the news happen on curves. Here's 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's no traction, inertia will keep
the vehicle going in the same direction. If you've ever
tried to steer a vehicle on wet ice, you'll 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're in a curve, speed is the one factor you
can control.

4-13
Suppose you're 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. Refer to ªTraction Assist
Systemº in the Index.
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'll want to go slower.
If you need to reduce your speed as you approach a
curve, do it before you enter the curve, while your front
wheels are straight ahead.
Try to adjust your speed so you can ªdriveº 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.
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 can't; there isn't room.
That's the time for evasive action
-- steering around
the problem.
Your vehicle can perform very well in emergencies like
these. First apply your brakes. See ªBraking in
Emergenciesº earlier in this section. 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.

4-14
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.
Off-Road Recovery
You may find that your right wheels have dropped off the
edge of a road onto the shoulder while you're 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 your steering wheel to go straight down
the roadway.

4-16

Check your mirrors, glance over your shoulder and
start your left lane change signal before moving out
of the right lane to pass. When you are far enough
ahead of the passed vehicle to see its front in your
inside mirror, activate your right lane change signal
and move back into the right lane. (Remember that
if your right outside mirror is convex, the vehicle
you just passed may seem to be farther away from
you than it really is.)

Try not to pass more than one vehicle at a time
on two
-lane roads. Reconsider before passing the
next vehicle.

Don't overtake a slowly moving vehicle too rapidly.
Even though the brake lamps are not flashing, it may
be slowing down or starting to turn.

If you're 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's review what driving experts say about what
happens when the three control systems (brakes, steering
and acceleration) don't have enough friction where the
tires meet the road to do what the driver has asked.
In any emergency, don't 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 ªoverdrivingº
those conditions. But skids are always possible.
The three types of skids correspond to your vehicle's
three control systems. In the braking skid, your wheels
aren't 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.

4-18
Off-Road Driving with Your
Four
-Wheel-Drive Vehicle
This off-road guide is for vehicles that have
four
-wheel drive.
Also, see ªAnti
-Lock Brakesº in the Index.
If your vehicle doesn't have four
-wheel drive, you
shouldn't drive off
-road unless you're on a level,
solid surface.
Off
-road driving can be great fun. But it does have
some definite hazards. The greatest of these is the
terrain itself.
ªOff
-roadingº means you've left the great North
American road system behind. Traffic lanes aren't
marked. Curves aren't banked. There are no road signs.
Surfaces can be slippery, rough, uphill or downhill.
In short, you've gone right back to nature.
Off
-road driving involves some new skills. And that's
why it's very important that you read this guide. You'll
find many driving tips and suggestions. These will help
make your off
-road driving safer and more enjoyable.If you think you will need some more ground clearance
at the front of your vehicle, you can easily remove the
front bumper lower air dam.
The front bumper lower air dam is held in place by a
series of push pins located around the lower edge of the
front bumper. The push
-pins are accessible from
underneath the front bumper.

4-21 Before You Go Off-Roading
There are some things to do before you go out.
For example, be sure to have all necessary maintenance
and service work done. Check to make sure all
underbody shields (if so equipped) are properly
attached. Be sure you read all the information about
your four
-wheel-drive vehicle in this manual. Is there
enough fuel? Is the spare tire fully inflated? Are the
fluid levels up where they should be? What are the local
laws that apply to off
-roading where you'll be driving?
If you don't know, you should check with law
enforcement people in the area. Will you be on
someone's private land? If so, be sure to get the
necessary permission.
Loading Your Vehicle for Off-Road Driving
There are some important things to remember about
how to load your vehicle.

The heaviest things should be on the load floor and
forward of your rear axle. Put heavier items as far
forward as you can.

Be sure the load is secured properly, so driving on
the off
-road terrain doesn't toss things around.
CAUTION:

Cargo on the load floor piled higher than
the seatbacks can be thrown forward
during a sudden stop. You or your
passengers could be injured. Keep cargo
below the top of the seatbacks.

Unsecured cargo on the load floor can
be tossed about when driving over rough
terrain. You or your passengers can
be struck by flying objects. Secure the
cargo properly.

Heavy loads on the roof raise the vehicle's
center of gravity, making it more likely to
roll over. You can be seriously or fatally
injured if the vehicle rolls over. Put heavy
loads inside the cargo area, not on the roof.
Keep cargo in the cargo area as far forward
and low as possible.
You'll find other important information in this manual.
See ªVehicle Loading,º ªLuggage Carrierº and ªTiresº
in the Index.

4-22 Environmental Concerns
Off-road driving can provide wholesome and satisfying
recreation. However, it also raises environmental
concerns. GM recognizes these concerns and urges
every off
-roader to follow these basic rules for
protecting the environment:

Always use established trails, roads and areas that
have been specially set aside for public off
-road
recreational driving; obey all posted regulations.

Avoid any driving practice that could damage the
environment
-- shrubs, flowers, trees, grasses -- or
disturb wildlife (this includes wheel
-spinning,
breaking down trees or unnecessary driving through
streams or over soft ground).

Always carry a litter bag . . . make sure all refuse is
removed from any campsite before leaving.

Take extreme care with open fires (where permitted),
camp stoves and lanterns.

Never park your vehicle over dry grass or other
combustible materials that could catch fire from the
heat of the vehicle's exhaust system.
Traveling to Remote Areas
It makes sense to plan your trip, especially when going
to a remote area. Know the terrain and plan your route.
You are much less likely to get bad surprises. Get
accurate maps of trails and terrain. Try to learn of any
blocked or closed roads.
It's also a good idea to travel with at least one other
vehicle. If something happens to one of them, the other
can help quickly.
Does your vehicle have a winch? If so, be sure to read
the winch instructions. In a remote area, a winch can be
handy if you get stuck. But you'll want to know how to
use it properly.

4-24 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.