wheel GMC SAVANA 2007 Owner's Guide

Let us say the road is wet and you are driving
safely. Suddenly, an animal jumps out in front of
you. You slam on the brakes and continue braking.
Here is 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 both rear wheels.ABS can change the brake pressure faster than any
driver could. The computer is programmed to make
the most of available tire and road conditions.
This can help you 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: ABS does 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 firmly and let anti-lock work for you.
You may feel the brakes vibrate, or you may notice
some noise, but this is normal.
Braking in Emergencies
With ABS, you can steer and brake at the same
time. In many emergencies, steering can help you
more than even the very best braking.
Locking Rear Axle
If your vehicle has this feature, 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.
StabiliTrak®System
If your vehicle has StabiliTrak®, it combines
anti-lock brake, traction and stability control
systems and helps the driver maintain directional
control of the vehicle in most driving conditions.
When you first start your vehicle and begin to drive
away, the system performs several diagnostic
checks to ensure that it is working properly. You
may hear or feel the system working. This is normal
and does not mean there is a problem with your
vehicle. The system should initialize before the
vehicle reaches 20 mph (32 km/h). In some cases,
it may take approximately 2 miles (3.2 km) of driving
before the system initializes.
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Pressing and holding
the StabiliTrak®button
located on the
instrument panel for
more than five seconds
can turn off StabiliTrak
®
and part of the
traction control system.
For your safety, the system can only be disabled
when the vehicle speed is less than 20 mph
(32 km/h). You will hear three chimes and the
StabiliTrak
®not ready light will come on.
To turn on the StabiliTrak
®system, press the
StabiliTrak®button again. StabiliTrak®will
automatically turn back on when the vehicle speed
exceeds 20 mph (32 km/h). You will hear one chime
and the StabiliTrak
®not ready light will turn off.
When the StabiliTrak
®system has been turned off
you may still hear system noises as a result of
the brake-traction control coming on.It is recommended to leave the system on for
normal driving conditions, but it may be necessary
to turn the system off if your vehicle is stuck in
sand, mud, ice or snow, and you want to “rock”
your vehicle to attempt to free it. SeeIf Your
Vehicle is Stuck in Sand, Mud, Ice, or Snow on
page 258.
StabiliTrak®System Operation
The StabiliTrak®system is normally on, except
when the system is initializing or has been
disabled with the StabiliTrak
®button. The
StabiliTrak®system will automatically activate to
assist the driver in maintaining vehicle directional
control in most driving conditions. When activated,
the StabiliTrak
®system may reduce engine
power to the wheels and apply braking to individual
wheels as necessary to assist the driver with
vehicle directional control. If your vehicle is
in cruise control when the system activates, the
StabiliTrak
®indicator light on the instrument panel
will flash, and the cruise control will automatically
disengage. When the StabiliTrak
®system is
no longer active, you may re-engage the cruise
control. SeeCruise Control on page 151.
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The StabiliTrak®system may also turn off
automatically if it determines that a problem exists
with the system. If the problem does not clear
itself after restarting the vehicle, you should see
your dealer for service.
Traction Control Operation
The traction control system is part of the
StabiliTrak®system. Traction control limits wheel
spin by reducing engine power to the wheels
(engine speed management) and by applying
brakes to each individual wheel (brake-traction
control) as necessary.
If the brake-traction control system activates
constantly or if the brakes have heated up due to
high speed braking, the brake-traction control
will be automatically disabled. The system
will come back on after the brakes have cooled.
This can take up to two minutes or longer
depending on brake usage.
The traction control system may activate on dry or
rough roads or under conditions such as heavy
acceleration while turning or abrupt upshifts/
downshifts of the transmission.When this happens you may notice a reduction in
acceleration, or may hear a noise or vibration.
This is normal.
Adding non-GM accessories can affect your
vehicle’s performance. SeeAccessories and
Modications on page 286for more information.All-Wheel Drive (AWD) System
If your vehicle has all-wheel drive, your engine’s
driving power is sent to all four wheels for
extra traction when needed.
This is like four-wheel drive, but there is no
separate lever or switch to engage or disengage
the front axle. It is fully automatic, and adjusts itself
as needed for road conditions.
You may experience a brief vehicle vibration upon
acceleration when driving in slippery conditions.
This is normal and is an indication that the
all-wheel drive system is functioning properly.
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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.
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 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 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
Modications on page 286.
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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 cannot; there is not room.
That is the time for evasive action — steering
around the problem.
Your vehicle can perform very well in emergencies
like these. First apply your brakes.
SeeBraking on page 232. 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.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.
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Off-Road Recovery
You may find that your right wheels have dropped
off the edge of a road onto the shoulder while you
are 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.
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:
•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.
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Loss of Control
Let us review what driving experts say about what
happens when the three control systems — brakes,
steering, and acceleration — do not have enough
friction where the tires meet the road to do what the
driver has asked.
In any emergency, do not 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 are not 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 will 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 reducing vehicle speed 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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•Lamps:Are they all working? Are the lenses
clean?
•Tires:They are vitally important to a safe,
trouble-free trip. Is the tread good enough
for long-distance driving? Are the tires
all inflated to the recommended pressure?
•Weather Forecasts:What is the weather
outlook along your route? Should you
delay your trip a short time to avoid a major
storm system?
•Maps:Do you have up-to-date maps?
Highway Hypnosis
Is there actually such a condition as highway
hypnosis? Or is it just plain falling asleep at
the wheel? Call it highway hypnosis, lack of
awareness, or whatever.There is something about an easy stretch of road
with the same scenery, along with the hum of
the tires on the road, the drone of the engine,
and the rush of the wind against the vehicle that
can make you sleepy. Do not let it happen to you!
If it does, your vehicle can leave the road in
less than a second, and you could crash and
be injured.
What can you do about highway hypnosis?
First, be aware that it can happen.
Then here are some tips:
•Make sure your vehicle is well ventilated,
with a comfortably cool interior.
•Keep your eyes moving. Scan the road ahead
and to the sides. Check your mirrors and your
instruments frequently.
•If you get sleepy, pull off the road into a rest,
service, or parking area and take a nap, get
some exercise, or both. For safety, treat
drowsiness on the highway as an emergency.
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What is the worst time for this? Wet ice. Very cold
snow or ice can be slick and hard to drive on.
But wet ice can be even more trouble because it
may offer the least traction of all. You can get
wet ice when it is about freezing, 32°F (0°C), and
freezing rain begins to fall. Try to avoid driving
on wet ice until salt and sand crews can get there.
Whatever the condition — smooth ice, packed,
blowing, or loose snow — drive with caution.Accelerate gently. Try not to break the fragile
traction. If you accelerate too fast, the drive wheels
will spin and polish the surface under the tires
even more.
The Anti-Lock Brake System (ABS) improves your
vehicle’s stability when you make a hard stop
on a slippery road. Even though you have ABS,
you will want to begin stopping sooner than
you would on dry pavement. SeeAnti-Lock Brake
System (ABS) on page 233.
•Allow greater following distance on any
slippery road.
•Watch for slippery spots. The road might be
fine until you hit a spot that is covered with
ice. On an otherwise clear road, ice patches
may appear in shaded areas where the
sun cannot reach, such as around clumps of
trees, behind buildings, or under bridges.
Sometimes the surface of a curve or an
overpass may remain icy when the
surrounding roads are clear. If you see a
patch of ice ahead of you, brake before you
are on it. Try not to brake while you are
actually on the ice, and avoid sudden steering
maneuvers.
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