traction control GMC SIERRA 1993 Owners Manual

Features & Controls
Four-Wheel-Drive Vehicles Only: If your vehicle has four-wheel drive and is
equipped with a manual transmission, disregard the shift light \
when the
transfer case is in
4 LOW.
Shift Speeds-Manual Transmission
This chart shows when to shift to the next higher gear for best fuel economy.
MANUAL TRANSMISSION RECOMMENDED SHIFT SPEED
IN MPH (KMIH)
Engine
and
VIN
45-50 25-40 50 40 15
4,3L
V6
3 to 4 2 to 3 1 to 2 3 to 4 2 to 3 1 to 2 Code
Trans. Cruise Shift Speed
Acceleration Shift Speed
(4
- (64) (40) (24) (K)
(72-80)
(40-64) - (80) (64)
(24)
5-Speed*
40 25 15 5.7L V8
- -
* Transmission with L (low) gear only. L (low) is intended for heavy loads and
is not recommended for normal driving.
I TO1 61 I
If your speed drops below 20 mph (32 km/h), or if the engine is not running
smoothly, you should downshift to the next lower gear. You may have to
downshift two or more gears
to keep the engine running smoothly or for good
performance.
I A If you skip more than one gear when you downshift, you could lose
I & control of your vehicle: And you could injure yourself or others. I
I Ju skip more than one gear when you downshift, or if you race the
;,,,ine when you downshift, you can damage the clutch or transmission. \
I
Locking Rear Axle
If you have this feature, your 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,
the locking feature
will allow the wheel with traction to move the vehicle.
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Features & Contmls
I Cruise Control can be dangerous where you can’t safely drive\
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 Contr\
ol
on slippery roads.
-
To Set Cruise Control
K2248
Move the Cruise switch to ON.
I CAUTION I
I 6 If you leave your Cruise Control switch on when you’re not usi\
ng
.,L Cruise, you might hit a button and go into Cruise when you d\
on’t
want to. You could be startled and even lose control. Keep the
Cruise Control switch
OFF until vou want to use it.
-
Get up to the speed you want.
Push in the set button at the end of the lever and release it,
Take your foot off the accelerator pedal.
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Your Driving and the Road
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.
The traction you can get in a curve depends on me 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.
Suppose you’re steering through a sharp curve. Then you sudd\
enly apply the
brakes. Both control systems-steering and braking-have to
do their work
where the tires meet the road. Adding the hard braking can de\
mand too
much at those places. You can lose control.
The same thing can happen
if you’re steering through a sharp curve and you
suddenly accelerate. Those two control systems-steering and
acceleration-can overwhelm those places where the tires meet the road and
make you lose control.
What should you
do if this ever happens? Let up on the brake or 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.
When you drive into a curve at night, it’s harder
to see the road ahead of
you because it bends away from the straight beams
of your lights. This is
one good reason to drive slower.
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Your Driving and the Road
the right lane. (Remember that your right outside mirror is c\
onvex. 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.
Don’t overtake a slowly moving vehicle too rapidly. Even though the
Reconsider before passing the next vehicle.
brake lights 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 whe\
n the three
control systems (brakes, steering and acceleration) don’t ha\
ve 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 steel+-, arid 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 possib\
le.
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.
A cornering skid and an acceleration skid are best handled by ea\
sing your
foot
off the accelerator pedal. If your vehicle starts to slide (as when you turn
a corner on a wet, snow-
or ice-covered road), ease your foot off the
accelerator pedal as soon as you feel the vehicle start to sl\
ide. Quickly steer
the way you want the vehicle
to go. If you start steering quickly enough, your
vehicle
will straighten out. As it does, straighten the front wheels.
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 surfaces because
stopping distance will be longer and vehicle control more limit\
ed.
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 slid\
e. You
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Tune your senses to different kinds of signals. -Your eyes, for example, meed
to constantly sweep the terrain for unexpected obstacles. Your .ears need
to
listen for unusual tire or engine sounds. With your arms, hands, feet, and
body you’ll need to respond
to vibrations and vehicle bounce.
Controlling your vehicle is the key
to successful off-road driving. One of the
best ways
to control your vehicle is to control your speed. Here .are some
things
to keep in mind. At higher speeds:
e you approach things fastar and you have less time to scan the terrain
for obstacles.
you have less time
to react. ‘I , ’C _. ’.
you have more vehicle bounce when you drive over obstacles.
you’ll need more distance for braking, especially since you’\
re on an unpaved surface.
CAUTION
When you’re driving off road, bouncing and quick changes in
direction can easily throw you out of position. This could cause you
to lose control and crash. So, whether you’re driving on or off the
road, you and your passengers should wear safety belts.
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 ta.ke you. over hard-packed dirt, gravel, rocks,\
grass, sand, mud, snow or ice. Each of these sutfaces 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?
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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 th\
ese surfaces, it’s
very easy to lose control. On wet ice, for example, the tract\
ion
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.
I A Driving on frozen lakes, ponds or rivers can be dangerous. I
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
on
I y.
.
Driving In Water
Light rain causes no special off-road driving problems. But hea\
vy rain can
mean flash flooding, and flood waters demand extreme caution.
Find out how deep the water is before you drive through
it. If it’s deep
enough to cover your wheel hubs, axles, or exhaust pipe, don’\
t try it-you
probably won’t get through. Also, water that deep can damage\
your axle and
other vehicle parts.
If the water isn’t too deep, then drive through it slowly. At fast speeds, water
splashes on your ignition system and your vehicle can stall. S\
talling can also
occur
if you get your tailpipe under water. And, as long as your tailp\
ipe is
under water, you’ll never be able to start your engine. Whe\
n you go through
water, remember that when your brakes get wet, it may take you longer to
stop.
Driving through rushing water can be dangerous. Deep water can \
sweep your vehicle downstream and you and your passengers could\

drown.
If it’s only inches deep, it can still wash away the ground
from under your tires, and you could lose traction and roll t\
he vehicle
over. Don’t drive throuah rushina water. I
If you have a diesel engine, see “Driving Through Water (Diese\
l Engines)” in
the Index for more information on driving through water.
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r CAUTION I
If you operate your vehicle with a tire that is badly underinflated, the
tire can overheat. An overheated tire can lose air suddenly or catcl.
fire. You or others could be injured. Be sure all tires (including the
spare,
if any) are properly inflated.
Buying New Tires
To find out what kind and size of tires you need, look at the Certificationflire
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 num\
ber. That
way, your vehicle will continue to have tires that are designed to give proper
endurance, handling, speed rating, traction, ride and other thin\
gs during
normal service on your vehicle. If your tires have an all-season tread design,
the TPC number will be followed by a
“MS” (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.
1 CAUTION
* Mixing tires could cause you to lose control while driving. If you mix
vehicle may not handle properly, and you could have a crash. Be
- ) tires of different sizes or types (radial and bias-belted tires), the
I sure to use the same size and type tires on all wheels. I
Uniform Tire Qua/ity Grading
The following information relates to the system developed by the United
States National Highway Traffic Safety Administration which grade\
s tires by
treadwear, traction and temperature performance. (This applies o\
nly to
vehicles sold in the United States.)
Treadwear
The treadwear grade is a comparative rating based on the wear rate of the
tire when tested under controlled conditions on a specified governmen\
t 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 var\
iations in
driving habits, service practices and differences in road characteristics and
climate.
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Service & Appearance Care
Traction-A, B, C
The traction grades, from highest to lowest are: A, B, and C. They 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 braking
(straight-ahead) traction tests and does not include cornering \
(turning) traction.
Temperature-A, B, C
The temperature grades are A (the highest), B, and C, representing the tire’s
resistance
to the generation of heat and its ability to dissipate heat when
tested under controlled conditions on a specified indoor laborat\
ory test wheel.
Sustained high temperature can cause the material of the tire to degenerate
and reduce tire life, and excessive temperature can lead to sudden tire
failure. The grade
C corresponds to a level ‘of performance which all
passenger car tires must meet under the Federal Motor Vehicle \
Safety
Standard
No. 109. Grades B and A represent higher levels of performance on
the laboratory test wheel than the minimum required by law.
Warning: The temperature grade for this tire is established for a tire that is
properly inflated and not overloaded. Excessive speed, underinfla\
tion, or
excessive loading, either separately or in combination, can caus\
e heat buildup
and possible tire failure.
These grades are molded on the sidewalls of passenger car tire\
s. While the tires available as standard or optional equipment on \
General Motors
vehicles may vary with respect to these grades, all such tires meet General
Motors performance standards and have been approved for use on \
General
Motors vehicles.
All passenger type (P Metric) tires must conform to Federal
safety requirements in addition to these grades.
Wheel AIignment and Tire Balance
The wheels on your vehicle were aligned and balanced carefully \
at the
factory to give you the longest tire
life and best overall performance.
In
most cases, you will not need to have your wheels aligned again.
However,
if you notice unusual tire wear or your vehicle pulling one way \
or
the other, the alignment may need to be reset. If you notice your vehicle
vibrating when driving on a smooth road, your wheels may need to be
rebalanced.
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