ESP GMC SONOMA 2003 User Guide

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 involvesperception timeand
reaction time.
First, you have to decide to push on the brake pedal.
That’sperception time.Then you have to bring up your
foot and do it. That’sreaction time.
Averagereaction timeis 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.
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.
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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 vehicles 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.
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
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 notashing, 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.
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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 is 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.
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 slide. You may not realize the surface 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.
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Environmental Concerns
Off-road driving can provide wholesome and satisfying
recreation. However, it also raises environmental
concerns. GM recognize these concerns and urge 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,owers, 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 openres (where permitted),
camp stoves and lanterns.
Never park your vehicle over dry grass or other
combustible materials that could catchre 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.
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Getting Familiar with Off-Road Driving
It’s a good idea to practice in an area that’s safe
and close to home before you go into the wilderness.
Off-road driving does require some new and different
skills. Here’s what we mean.
Tune your senses to different kinds of signals. Your
eyes, for example, need 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:
you approach things faster and you have less time
to scan the terrain for obstacles.
you have less time to react.
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 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.
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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
arm 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 reexes, 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. SeeDrunken Driving on page 4-2.
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Driving at Night
Night driving is more dangerous than day driving. One
reason is that some drivers are likely to be impaired—by
alcohol or drugs, with night vision problems, or by fatigue.
Here are some tips on night driving.
Drive defensively.
Don’t drink and drive.
Adjust your inside rearview mirror to reduce the
glare from headlamps behind you.
Since you can’t see as well, you may need to slow
down and keep more space between you and
other vehicles.
Slow down, especially on higher speed roads. Your
headlamps can light up only so much road ahead.
In remote areas, watch for animals.
If you’re tired, pull off the road in a safe place
and rest.
No one can see as well at night as in the daytime.
But as we get older these differences increase.
A 50-year-old driver may require at least twice as much
light to see the same thing at night as a 20-year-old.
What you do in the daytime can also affect your
night vision. For example, if you spend the day in bright
sunshine you are wise to wear sunglasses. Your
eyes will have less trouble adjusting to night. But if
you’re driving, don’t wear sunglasses at night. They may
cut down on glare from headlamps, but they also
make a lot of things invisible.
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Hydroplaning
Hydroplaning is dangerous. So much water can build up
under your tires that they can actually ride on the
water. This can happen if the road is wet enough and
you’re going fast enough. When your vehicle is
hydroplaning, it has little or no contact with the road.
Hydroplaning doesn’t happen often. But it can if
your tires do not have much tread or if the pressure in
one or more is low. It can happen if a lot of water is
standing on the road. If you can see reections
from trees, telephone poles or other vehicles, and
raindrops“dimple”the water’s surface, there could be
hydroplaning.
Hydroplaning usually happens at higher speeds.
There just isn’t a hard and fast rule about hydroplaning.
The best advice is to slow down when it is raining.
Driving Through Deep Standing Water
Notice:If you drive too quickly through deep
puddles or standing water, water can come in
through your engine’s air intake and badly damage
your engine.Never drive through water that is
slightly lower than the underbody of your vehicle.
If you can’t avoid deep puddles or standing
water, drive through them very slowly.
Driving Through Flowing Water
{CAUTION:
Flowing or rushing water creates strong forces.
If you try to drive through flowing water, as you
might at a low water crossing, your vehicle can
be carried away.As little as six inches of
flowing water can carry away a smaller vehicle.
If this happens, you and other vehicle
occupants could drown.Don’t ignore police
warning signs, and otherwise be very cautious
about trying to drive through flowing water.
Some Other Rainy Weather Tips
Besides slowing down, allow some extra following
distance. And be especially careful when you
pass another vehicle. Allow yourself more clear
room ahead, and be prepared to have your
view restricted by road spray.
Have good tires with proper tread depth.
SeeTires on page 5-58.
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{CAUTION:
Snow can trap exhaust gases under your
vehicle. This can cause deadly CO (carbon
monoxide) gas to get inside. CO could
overcome you and kill you. You can’t see it or
smell it, so you might not know it is in your
vehicle. Clear away snow from around the
base of your vehicle, especially any that is
blocking your exhaust pipe. And check around
again from time to time to be sure snow
doesn’t collect there.
Open a window just a little on the side of the
vehicle that’s away from the wind. This will
help keep CO out.Run your engine only as long as you must. This saves
fuel. When you run the engine, make it go a little
faster than just idle. That is, push the accelerator
slightly. This uses less fuel for the heat that you get and
it keeps the battery charged. You will need a
well-charged battery to restart the vehicle, and possibly
for signaling later on with your headlamps. Let the
heater run for a while.
Then, shut the engine off and close the window almost
all the way to preserve the heat. Start the engine
again and repeat this only when you feel really
uncomfortable from the cold. But do it as little as
possible. Preserve the fuel as long as you can. To help
keep warm, you can get out of the vehicle and do
some fairly vigorous exercises every half hour or so until
help comes.
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Trailer Brakes
If your trailer weighs more than 1,000 lbs. (450 kg)
loaded, then it needs its own brake–and they must be
adequate. Be sure to read and follow the instructions for
the trailer brakes so you’ll be able to install, adjust
and maintain them properly.
Your trailer’s brake system can tap into the vehicle’s
hydraulic brake system only if:
The trailer parts can withstand 3,000 psi
(20 650 kPa) of pressure.
The trailer’s brake system will use less than
0.02 cubic inch (0.3 cc) ofuid from your vehicle’s
master cylinder. Otherwise, both braking systems
won’t work well. You could even lose your brakes.
If everything checks out this far, then make the brake
uid tap at the port on the master cylinder that
sendsuid to the rear brakes. But don’t use copper
tubing for this. If you do, it will bend andnally break off.
Use steel brake tubing.
Driving with a Trailer
Towing a trailer requires a certain amount of experience.
Before setting out for the open road, you’ll want to get
to know your rig. Acquaint yourself with the feel of
handling and braking with the added weight of the trailer.
And always keep in mind that the vehicle you are
driving is now a good deal longer and not nearly as
responsive as your vehicle is by itself.
Before you start, check the trailer hitch and platform
(and attachments), safety chains, electrical connector,
lamps, tires and mirror adjustment. If the trailer has
electric brakes, start your vehicle and trailer moving and
then apply the trailer brake controller by hand to be
sure the brakes are working. This lets you check your
electrical connection at the same time.
During your trip, check occasionally to be sure that the
load is secure, and that the lamps and any trailer
brakes are still working.
Following Distance
Stay at least twice as far behind the vehicle ahead as
you would when driving your vehicle without a trailer.
This can help you avoid situations that require
heavy braking and sudden turns.
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