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 are driving on snow or ice,
it is easy to ask more of those control systems than the
tires and road can provide. That means you can lose
control of your vehicle. SeeEnhanced Traction System
(ETS) on page 4-10.
Adding non-GM accessories can affect your vehicle’s
performance. SeeAccessories and Modifications
on page 5-3.
Braking
SeeBrake System Warning Light on page 3-32.
Braking action involves perception time and
reaction time.
First, you have to decide to push on the brake pedal.
That is perception time. Then you have to bring up your
foot and do it. That is reaction time.
Average reaction time is about three-fourths of a
second. But that is 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 three-fourths 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 is pavement or
gravel; the condition of the road, whether it is wet, dry, or
icy; tire tread; the condition of your brakes; the weight of
the vehicle; and the amount of brake force applied.
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Remember: ABS not 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 will not 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 ABS.
Using ABS
Do not pump the brakes. Just hold the brake pedal
down rmly and let anti-lock work for you. You may feel
a slight brake pedal pulsation or notice some noise,
but this is normal.
Braking in Emergencies
At some time, nearly every driver gets into a situation
that requires hard braking.
If you have ABS, you can steer and brake at the same
time. However, if you do not have ABS, your rst
reaction — to hit the brake pedal hard and hold it
down — may be the wrong thing to do. Your wheels can
stop rolling. Once they do, the vehicle cannot respondto your steering. Momentum will carry it in whatever
direction it was headed when the wheels stopped rolling.
That could be off the road, into the very thing you
were trying to avoid, or into traffic.
If you do not have ABS, use a “squeeze” braking
technique. This will give you maximum braking while
maintaining steering control. You can do this by pushing
on the brake pedal with steadily increasing pressure.
In an emergency, you will probably want to squeeze the
brakes hard without locking the wheels. If you hear or
feel the wheels sliding, ease off the brake pedal.
This will help you retain steering control. If you do have
ABS, it is different. SeeAnti-Lock Brake System
(ABS) on page 4-7.
In many emergencies, steering can help you more than
even the very best braking.
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To limit wheel spin, especially in slippery road
conditions, you should always leave the Enhanced
Traction System on. But you can turn the system off
if you prefer.
To turn the system off, shift to LOW (L) or REVERSE (R).
When you turn the system off, the Enhanced Traction
System warning light will come on and stay on when the
gear shift is in LOW (L). The warning light will not come
on when the gear shift is in REVERSE (R). If the
Enhanced Traction System is limiting wheel spin when
you shift to LOW (L) or REVERSE (R) to turn the system
off, the warning light will come on in LOW (L). But the
system won’t turn off right away. It will wait until there’s no
longer a current need to limit wheel spin.
You can turn the system back on at any time by
shifting to AUTOMATIC OVERDRIVE (D) or
INTERMEDIATE (I). The Enhanced Traction System
warning light should go off.
Adding non-GM accessories can affect your vehicle’s
performance. SeeAccessories and Modifications
on page 5-3for more information.Steering
Electric Power Steering
If the engine stalls while you are driving, the power
steering assist system will continue to operate until you
are able to stop your vehicle. If you lose power
steering assist because the electric power steering
system is not functioning, you can steer, but it will take
more effort.
If you turn the steering wheel in either direction several
times until it stops, or hold the steering wheel in the
stopped position for an extended amount of time, you
may notice a reduced amount of power steering
assist. The normal amount of power steering assist
should return shortly after a few normal steering
movements.
The electric power steering system does not require
regular maintenance. If you suspect steering system
problems and/or the POWER STEERING message
comes on, contact your dealer for service repairs.
SeeDIC Warnings and Messages on page 3-43.
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Steering Tips
It is important to take curves at a reasonable speed.
A lot of the “driver lost control” accidents mentioned on
the news happen on curves. Here is 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 is no traction, inertia
will keep the vehicle going in the same direction.
If you have ever tried to steer a vehicle on wet ice,
you will 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 are in a curve, speed is the one factor you
can control.
Suppose you are steering through a sharp curve.
Then you suddenly apply the brakes. Both control
systems — steering and braking — have to do their work
where the tires meet the road. Unless you have
four-wheel anti-lock brakes, adding the hard braking
can demand too much of those places. You can
lose control.The same thing can happen if you are 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. SeeEnhanced Traction
System (ETS) on page 4-10.
What should you do if this ever happens? Ease 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 will 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.
Adding non-GM accessories can affect your vehicle’s
performance. SeeAccessories and Modifications
on page 5-3.
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