1997 CHEVROLET SUBURBAN Owners Manual

Control of a Vehicle
You have three systems that make your vehicle go where
you want it to
go. They are the brakes, the steering and
the accelerator. All three systems have to do their work
at the places where the tires meet the road.
Sometimes,
as when you’re driving on snow or ice, it’s
easy to ask more
of those control systems than the tires
and road can provide. That means you can lose control
of your vehicle.
Braking
Braking action involves perception time and
reaction time.
First, you have to decide to push on the brake pedal.
That’s
perception time. Then you have to bring up your
foot and do it. That’s reaction time.
Average reaction time is about 3/4 of a second. But
that’s only an average. It might be less with one driver
and as long as two or three seconds or more with
another. Age, physical condition, alertness, coordination
and eyesight all play a part.
So do alcohol, drugs and
frustration. But even
in 3/4 of a second, a vehicle
moving at
60 mph (100 km/h) travels 66 feet (20 m).
That could be a lot of distance in an emergency,
so
keeping enough space between your vehicle and others
is important.
And,
of course, actual stopping distances vary greatly
with the surface
of the road (whether it’s pavement or
gravel); the condition of the road (wet, dry, icy); tire
tread;
the condition of your brakes; the weight of the
vehicle and the amount
of brake force applied.
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Avoid needless heavy braking. Some people drive in
spurts
-- heavy acceleration followed by heavy
braking
-- rather than keeping pace with traffic. This is a
mistake. Your brakes may not have time to cool between
hard stops. Your brakes will wear out much faster if you
do a lot of heavy braking. If you keep pace with the
traffic and allow realistic following distances, you will
eliminate a lot
of unnecessary braking. That means
better braking and longer brake life.
If your engine ever stops while you’re driving, brake
normally but don’t pump your brakes. If you do, the
pedal may get harder to push down. If your engine
stops, you will still have some power brake assist. But
you will use it when you brake. Once the power assist is
used up, it may take longer to stop and the brake pedal
will be harder to push.
Anti-Lock Brakes (ABS)
Your vehicle has anti-lock brakes (ABS). ABS is an
advanced electronic braking system that will help
prevent a braking skid.
When you start your engine and begin to drive away,
your anti-lock brake system will check itself. You may
hear a momentary motor or clicking noise while this test
is going on. This is normal.
ANTI -
LOCK
If there’s a problem with the
anti-lock brake system, this
warning light will stay on.
See “Anti-Lock Brake
System Warning Light” in
the Index.
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Here’s how anti-lock works. Let’s say the road is wet.
You’re driving safely. Suddenly an animal jumps out in
front
of you.
You slam on the brakes. Here’s what happens with ABS.
A computer senses that wheels are slowing down. If one
of the wheels is about to stop rolling, the computer will
separately work the brakes at each front wheel and at the
rear wheels. The
anti-lock system can change the brake pressure
faster than any driver could. The computer is
programmed to make the most of available tire and
road conditions.
You can steer around the obstacle while braking hard. As you brake, your computer keeps receiving updates on
wheel speed and controls braking pressure accordingly.
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Remember: 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.
Using Anti-Lock
Don’t pump the brakes. Just hold the brake pedal down
and let anti-lock work for
you. You may feel the brakes
vibrate, or you may notice some noise, but this is
normal. On vehicles with four-wheel drive, your
anti-lock brakes work at all times
-- whether you are in
two-wheel drive 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
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.
Variable Effort Steering
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 for vehicle control and stability.
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 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.
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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.
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 you can from a possible
collision. Then steer around the problem, to the left or
right depending on the space available.
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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 sometime 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.
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Passing
The driver of a vehicle about to pass another on a
two-lane highway waits for just the right moment,
accelerates, moves around the vehicle ahead, then goes
back into the right lane again. A simple maneuver?
Not necessarily! Passing another vehicle on a two-lane
highway is a potentially dangerous move, since the
passing vehicle occupies the same lane as oncoming
traffic for several seconds. A miscalculation, an error in
judgment, or a brief surrender to frustration or anger can
suddenly put the passing driver face to face with the
worst of all traffic accidents
-- the head-on collision.
So here are some tips for passing:
0 “Drive ahead.” Look down the road, to the sides and to
crossroads for situations that might affect your passing
patterns.
If you have any doubt whatsoever about
making a successful pass, wait for a better time.
Watch for traffic signs, pavement markings and lines.
If you can see a sign up ahead that might indicate a
turn or an intersection, delay your pass. A broken
center line usually indicates it’s all right to pass
(providing the road ahead is clear). Never cross a solid
line on your side of the lane or a double solid line,
even
if the road seems empty of approaching tr&k.
Do not get too close to the vehicle you want to pass
while you’re awaiting an opportunity. For one thing,
following too closely reduces your area of vision,
especially if you’re following a larger vehicle. Also.
you won’t have adequate space if the vehicle
ahead suddenly slows or stops. Keep back a
reasonable distance.
When it looks like a chance to pass is coming up,
start to accelerate but stay in the right lane and don’t
get too close. Time your move
so you will be
increasing speed as the time comes to move into the
other lane. If the way is clear to pass, you will have
a
“running start” that more than makes up for the
distance you would lose by dropping back. And
if
something happens to cause you to cancel your pass,
you need only slow down and drop back again and
wait for another opportunity.
If other cars are lined up to pass a slow vehicle, wait
your
turn. But take care that someone isn’t trying to
pass you as you pull out to pass the slow vehicle.
Remember to glance over your shoulder and check
the blind spot.
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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
“overdriving” 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.
A cornering skid and an acceleration skid are best
handled by easing your foot
off the accelerator pedal.
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
surfaces because stopping distance will be longer and
vehicle control more limited.
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