Braking
SeeBrake System Warning Light on page 3-41.
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.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 are driving, brake
normally but do not 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.
Adding non-GM accessories can affect your vehicle’s
performance. SeeAccessories and Modi cations
on page 5-3.
4-6
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 your engine and begin to drive away,
ABS will check itself. You may hear a momentary motor
or clicking noise while this test is going on. This is normal.
If there is a problem with
ABS, this warning light will
stay on. SeeAnti-Lock
Brake System Warning
Light on page 3-42.
Along with ABS, your vehicle has a Dynamic Rear
Proportioning (DRP) system. If there is a DRP problem,
both the brake and ABS warning lights will come on
accompanied by a 10-second chime. The lights and
chime will come on each time the ignition is turned on
until the problem is repaired. See your dealer for service.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.
4-7
When the system is turned off, the traction off light
will illuminate, and the STABILITY SYS DISABLED
message will appear on the DIC to warn the driver
that both the stability system and part of the traction
control system are disabled. Your vehicle will still have
brake-traction control when StabiliTrak
®is off, but
will not be able to use the engine speed management
system. See “Traction Control Operation” next for
more information.
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. 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 4-46.
When the transfer case is in 4LO, the stability system
is automatically disabled, and the STABILITY SYS
DISABLED message will appear on the DIC. In 4LO,
the StabiliTrak
®button only turns the traction control
system on and off.
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, and it will activate
and display the TRACTION ACTIVE message in the
Driver Information Center (DIC) if it senses that any of
the wheels are spinning or beginning to lose traction
while driving. If you turn off StabiliTrak
®, only the
brake-traction control portion of traction control will work.
The engine speed management will be disabled. In
this state, engine power is not reduced automatically
and the driven wheels can spin more freely. This
can cause the brake-traction control to activate
constantly. For more information on the traction
active message, seeDriver Information Center (DIC)
on page 3-51.
Notice:If the traction off light comes on due to
heavy braking and/or because the traction control
system has been continuously active, do not
allow the wheel(s) of one axle to spin excessively.
If you do, you may be causing damage to the
transfer case. This could lead to costly repairs not
covered by your warranty.
4-10
If the brake traction-control system activates constantly
or if the brakes have heated up due to high speed
braking, brake traction-control will be disabled and the
TRACTION SYS LIMITED message will be displayed.
In the limited mode, the traction-control system will only
use engine traction-control and is limited in it’s ability
to provide optimal performance since the system will
not utilize brake traction-control to control slip on
the drive wheels. The system will return to normal
operation after the brakes have cooled. This can take
up to two minutes or longer depending on brake usage.
Notice:If you allow the wheel(s) of one axle to
spin excessively while the traction off, ABS
and brake warning lights and the SERVICE
STABILITY 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.
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 STABILITY SYS ACTIVE message will
appear on the Driver Information Center (DIC), 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 3-11.
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 for service.
All-Wheel Drive (AWD) System
If your vehicle has this feature, engine power is sent
to all four wheels all the time.
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.
4-11
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. SeeStabiliTrak
®System
on page 4-9.
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 Modi cations
on page 5-3.
4-12
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.Remember: StabiliTrak
®helps avoid only the
acceleration skid. SeeStabiliTrak®System on page 4-9.
If the StabiliTrak®System is off, then an acceleration
skid is also 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 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.
4-16
The following steps must be performed on each of the
push-pins to remove the air dam:
1. Insert a tool into the
push-pin slot and pull
downward until the
push-pin snaps loose.
2. While continuing to
pull downward on the
push-pin, squeeze
and turn the
expandable end of the
push-pin with a tool
until it releases
from the retainer.3. Pull the push-pins and
lower air dam assembly
away from the
retainers until the lower
air dam is free.
When you are back on roads, though, be sure to
replace the air dam.
Notice:Operating your vehicle for extended
periods without the front bumper lower air dam
installed can cause improper air ow to the engine
and may allow things like fog lamps or tow hooks
on the front of your vehicle to be damaged. Always
be sure to replace the front bumper air dam when
you are nished off-road driving.
4-18
Getting Familiar with Off-Road Driving
It is a good idea to practice in an area that is safe
and close to home before you go into the wilderness.
Off-road driving does require some new and different
skills. Here is 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 will 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 will need more distance for braking, especially
since you are on an unpaved surface.
{CAUTION:
When you are 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 are
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.
4-22