1998 GMC ENVOY traction control

Locking Rear Axle
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.
Four-wheel Drive
Because your vehicle has four-wheel drive, you can
send your engine’s driving power to all four wheels for
extra traction.
To shift out of two-wheel drive and into
four-wheel drive, push the
4HI or 4LO button on the
transfer case switch. You should use
2HI for most
normal driving conditions.
Driving in the 4HI or 4LO positions for a long
time on dry
or wet pavement could shorten the
life
of your vehicle’s drivetrain.
Electronic Transfer Case
The transfer case switches
are above the radio controls.
Use
these switches to shift into and out of four-wheel
drive.
You can choose among three driving settings:
2HI: This setting is for driving in most street and
highway situations. Your front axle is not engaged in
two-wheel drive.
4HI: This setting engages your front axle to help drive
your vehicle. Use
4HI when you need extra traction,
such as on snowy or icy roads, or in most
off-road situations.
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CAUTION:
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Cruise control can be dangerous where you
can’t drive safely
at a steady speed. So,
don’t 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. Don’t
use cruise control on slippery roads.
I ,A CAUTION: I
If you leave your cruise control switch on when
you’re not using cruise, you might hit a button
and go into cruise when
you don’t want to. You
could be startled and even lose control. Keep the
cruise control switch off until you want to use it.
1. Move the cruise control switch to ON.
2. Get up to the speed you want.
3. Press in the SET button
at
the end of the lever
and release it.
4. Take your foot off the accelerator pedal.
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Re,member: Anti-lock doesn’t 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 won’t 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.
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.
Using Anti-Lock
Don‘t pump the brakes. Just hold the brake pedal down
firmly and let anti-lock work for you. You may feel the
brakes vibrate,
or YOLI may notice some noise, but
this is normal. Your anti-lock brakes work at all
times
-- whether you are in two-wheel or
four-wheel drive.
Braking in Emergencies
With anti-lock, you can steer and brake at the same
time.
In many emergencies, steering can help you more
than even the very best braking.
Steering Tips
Driving on Curves
It’s important to take curves at a reasonable speed.
A lot of the “driver lost control“ 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.
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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
YOLK speed. While
you’re
in a curve, speed is the one factor you
can control.
Suppose you’re steering through a sharp curve.
Then you suddenly accelerate. Both control
systems
-- steering and acceleration -- have to do
the.ir 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’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 “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.
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 “Braking
in
Emergencies” earlier in this section.) It is better to
remove
as much speed as YOLI can from a possible
collision. Then steer around the problem, to
the left or
right depending on the space available.
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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‘ll
want to slow down and adjust your driving to these
conditions.
It is important to slow down on slippery
surfxes because stopping distance will be longer and
vehicle control more limited.
While driving on a surfxe
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 surfdce 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 Gu idelines
This multipurpose passenger vehicle is defined as a
utility vehicle in Consumer Information Regulations
issued by the National Highway Traffic Safety
Administration (NHTSA) of
the United States
Department of Transportation. Utility vehicles have
higher ground clearance and a narrower track to make
them capable of performing in a wide variety of off-road
applications. Specific design characteristics give them a
higher center of gravity than ordinary cars. An
advantage of the higher ground clearance is a better
view of the road allowing you
to anticipate problems.
They are not designed for cornering at
the same speeds
as conventional two-wheel-drive vehicles any more than
low-slung sports cars are designed to perform
satisfxtorily under off-road conditions.
If at all
possible, avoid sharp turns
or abrupt maneuvers. As with
other vehicles of this type, failure to operate this vehicle
correctly
may result in loss of control or
vehicle rollover.
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Scanning the Terrain
Off-road driving can take you over many different kinds
of terrain.
You need to be familiar with the telrain and its
many different features. Here are some things to consider.
S~lr$uce Conditions. Off-roading can take you over
hard-packed dirt, gravel, rocks, grass, sand, mud, snow
or ice. Each of these surfaces affects the steering,
acceleration and braking of your vehicle
in different
ways. Depending upon the kind of surface
you are on,
you may experience slipping, sliding, wheel spinning,
delayed acceleration, poor traction and longer
braking distances.
Su$ace Obstucles . 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:
0 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
surhce 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 "Drunken Driving"
in the Index.
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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
matt how
well built the vehicle.
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.
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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
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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 Inaneuvers'!
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 of'ten have
ruts, gullies, troughs and exposed rocks because they
are more susceptible to the effects of erosion.
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Getting out on the downhill (low) side of a vehicle
stopped across an incline is dangerous.
If the
vehicle rolls over, you could be crushed
or killed.
Always get out on the uphill (high) side of the
vehicle and stay well clear of the rollover path.
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.
LA CAU-ION:
Driving on frozen lakes, ponds or ~ ~ rers 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.
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