2007 GMC ACADIA wheel

But you will use it when you brake. Once the
power assist is used up, it can take longer to stop
and the brake pedal will be harder to push.
Adding non-dealer/non-retailer accessories can
affect your vehicle’s performance. SeeAccessories
and Modifications on page 385.
Anti-Lock Brake System (ABS)
Your vehicle has the Anti-Lock Brake System
(ABS), an advanced electronic braking system that
will help prevent a braking skid.
When you start the engine and begin to drive
away, ABS will check itself. You might hear
a momentary motor or clicking noise while this test
is going on, and you might even notice that the
brake pedal moves a little. This is normal.
If there is a problem
with ABS, this warning
light will stay on.
SeeAnti-Lock Brake
System Warning
Light on page 223.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
wheel.
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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, the computer keeps receiving
updates on wheel speed and controls braking
pressure accordingly.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 the 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 might hear the anti-lock pump or motor
operate, and feel the brake pedal pulsate, 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.
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Traction control can be turned on by pressing and
releasing the traction control disable button if
not automatically shut off for any other reason.
When the traction control system is turned
off, the StabiliTrak
®light and the appropriate
traction control off message will be displayed on
the DIC to warn the driver. Your vehicle will
still have brake-traction control when traction
control is off, but will not be able to use the engine
speed management system. See “Traction
Control Operation” next for more information.
When the traction control 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. It may also
be necessary to turn off the system when driving
in extreme off-road conditions where high wheel
spin is required. SeeIf Your Vehicle is Stuck
in Sand, Mud, Ice, or Snow on page 360.
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.
The traction control system is enabled automatically
when you start your vehicle. It will activate and the
StabiliTrak
®light will ash if it senses that any of the
wheels are spinning or beginning to lose traction
while driving. If you turn off traction control, only the
brake-traction control portion of traction control will
work. The engine speed management will be
disabled. In this mode, engine power is not reduced
automatically and the driven wheels can spin more
freely. This can cause the brake-traction control to
activate constantly.
Notice:If you allow the wheel(s) of one axle
to spin excessively while the StabiliTrak
®,
ABS and brake warning lights and the SERVICE
STABILITRAK message are displayed, you
could damage the transfer case. The repairs
would not be covered by your warranty.
Reduce engine power and do not spin the
wheel(s) excessively while these lights and this
message are displayed.
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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.
If your vehicle is in cruise control when the system
activates, the StabiliTrak
®light will ash and the
cruise control will automatically disengage.
When road conditions allow you to use cruise
again, you may re-engage the cruise control.
SeeCruise Control on page 180.
StabiliTrak
®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/retailer
for service.
All-Wheel Drive (AWD) System
If your vehicle has this feature, engine power is
sent to all four wheels when extra traction is
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.
When using a compact spare tire on your AWD
equipped vehicle, the AWD system automatically
detects the presence of the compact spare
and the AWD is disabled. To restore the AWD
operation and prevent excessive wear on
the clutch in your AWD system, replace the
compact spare with a full-size tire as soon as
possible. SeeCompact Spare Tire on page 477
for more information.
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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 the 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.
SeeStabiliTrak
®System on page 337.
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
the front wheels are straight ahead.
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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-dealer/non-retailer accessories can
affect your vehicle’s performance. SeeAccessories
and Modifications on page 385.
Steering in Emergencies
There are times when steering can be more
effective than braking. For example, you come
over a hill and nd 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 the brakes. SeeBraking
on page 334. 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 nd that your vehicle’s 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 nothingin 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 the 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.
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The three types of skids correspond to your
vehicle’s three control systems. In the braking skid,
the 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 want to slow down and adjust your
driving to these conditions. It is important to slow
down on slippery surfaces because stopping
distance is 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 might 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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