HUMMER H3 2008 Owners Manual

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 antilock work for you. You might feel the
brakes vibrate or 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.
Traction Control System (TCS)
Your vehicle has a Traction Control System (TCS) that
limits wheel spin. This is especially useful in slippery road
conditions. The system operates only if it senses that any
of the wheels are spinning or beginning to lose traction.
When this happens, the system applies the brakes to limit
wheel spin and also reduces engine power. You may feel
or hear the system working, but this is normal.
The Traction Control System may operate on dry roads
under some conditions. When this happens, you may
notice a reduction in acceleration or a pumping sound.
This is normal and doesn’t mean there’s a problem with
your vehicle. Examples of these conditions include hard
acceleration in a turn, an abrupt upshift or downshift of
the transmission or driving on rough roads.
If your vehicle is in cruise control when the TCS begins
to limit wheel spin, the cruise control will automatically
disengage. When road conditions allow you to safely
use it again, you may re-engage the cruise control.
SeeCruise Control on page 3-11.
If your vehicle has a Driver information Center (DIC),
a TRACTION FAULT message will appear when a
Traction Control System or Anti-Lock Brake System
problem has been detected and the vehicle needs
service. SeeDIC Warnings and Messages on page 3-43
for more information.
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When this message is on, the system will not limit
wheel spin. Adjust your driving accordingly.
The traction control system automatically comes on
whenever you start your vehicle. To limit wheel
spin, especially in slippery road conditions, you should
always leave the system on. But you can turn the
traction control system off if you ever need to.
To turn the system off,
press and hold the TCS
button for ve seconds.
This light will come
on steady when the
traction control system
has been turned off.
This light ashes when
TCS is active.If you press and hold the TC button for ve seconds,
the traction control system will turn off and a TRAC OFF
message will appear on the DIC. Press the TC button
again to turn the system back on. The TRAC OFF
message will then go off. The traction control system
will reset itself at each ignition cycle.
Adding non-dealer/non-retailer accessories can affect
your vehicle’s performance. SeeAccessories and
Modifications on page 5-3for more information.
Locking Rear Axle
Your vehicle may have this feature. The locking rear axle
can give your vehicle additional traction from the rear
wheels when traveling in off-road situations such as mud,
snow, sand, steep hills and uneven terrain.
The button used to turn
this feature on or off is
located to the right of
the transfer case buttons
on the center of the
instrument panel.
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To lock the rear axle, do the following:
1. Place the transfer case in the 4LO Lock mode. This
is the only mode which will allow the rear axle to
lock. SeeFull-Time Four-Wheel Drive on page 2-27
for more information regarding the transfer case
and 4LO Lock mode.
2. Press the button with the vehicle stopped or moving
less than 2 mph (3 km/h).
You must wait for the light in the button to stop ashing
and remain illuminated before the rear axle is locked.
Notice:If you try to lock the rear axle while your
vehicle is stuck and the tires are spinning, you
could damage your vehicle’s drivetrain. The repairs
would not be covered by your warranty. Always lock
the rear axle before attempting situations and/or
navigating terrain which could possibly cause the
vehicle to become stuck.
The locking rear axle will be disengaged when the
wheel speed is greater than 20 mph (32 km/h), if the
vehicle’s battery is low and/or the transfer case is
shifted out of 4LO Lock mode.
Notice:If you lock the rear axle while driving on
pavement, you could damage your vehicle’s
drivetrain. The repairs would not be covered by
your warranty. Do not use the locking rear axle
on pavement. If you need four-wheel drive when
traveling on pavement, use only 4HI.StabiliTrak®System
Your vehicle has a vehicle stability enhancement
system called StabiliTrak®. It is an advanced computer
controlled system that assists you with directional
control of the vehicle in difficult driving conditions.
StabiliTrak
®activates when the computer senses a
discrepancy between your intended path and the
direction the vehicle is actually traveling. StabiliTrak
®
selectively applies braking pressure at any one of
the vehicle’s brakes to assist the driver with keeping
the vehicle on the intended path.
When you rst start your vehicle and begin to drive
away, the system performs several diagnostic checks to
insure there are no problems. You may hear or feel
the system working. This is normal and does not mean
there is a problem with your vehicle.
If there is a problem detected with StabiliTrak
®,a
SERVICE STAB SYS message will be displayed on the
Driver Information Center (DIC). SeeDIC Warnings
and Messages on page 3-43for more information. When
this message is displayed, the system is not operational.
Adjust your driving accordingly.
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StabiliTrak®comes on automatically whenever you
start your vehicle. However, when the transfer case is
placed in Four-Wheel-Low Lock mode, StabiliTrak
®
is automatically disabled. SeeFull-Time Four-Wheel
Drive on page 2-27for more information. To help assist
you with directional control of the vehicle, you should
always leave the system on. You can turn StabiliTrak
®
off if you ever need to using the TC (traction control)
on/off button. If you press and hold the TC button for
ve seconds, the StabiliTrak
®system and the traction
control system will turn off. When this is done, the
STAB SYS OFF message will be displayed on the DIC.
Press the TC button again to turn StabiliTrak
®back
on. SeeTraction Control System (TCS) on page 4-5.
If your vehicle is in cruise control when the StabiliTrak
®
activates, the cruise control will automatically
disengage. When road conditions allow you to safely
use it again, you may reengage the cruise control.
SeeCruise Control on page 3-11for more information.
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. SeeTraction Control System (TCS)
on page 4-5andStabiliTrak
®System on page 4-7.
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.
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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.
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 5-3.
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 4-3.
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.
4-9

Off-Road Recovery
You may nd 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 the steering wheel to
go straight down the roadway.
Passing
Passing another vehicle on a two-lane road can be
dangerous. To reduce the risk of danger while passing,
we suggest the following tips:
Look down the road, to the sides, and to crossroads
for situations that might affect a successful pass.
If in doubt, wait.
Watch for traffic signs, pavement markings, and
lines that could indicate a turn or an intersection.
Never cross a solid or double-solid line on your
side of the lane.
Do not get too close to the vehicle you want to
pass. Doing so can reduce your visibility.
Wait your turn to pass a slow vehicle.
When you are being passed, ease to the right.
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.
4-10

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, 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.
Remember: Any traction control system helps avoid
only the acceleration skid. If your traction system is
off, then an acceleration skid is also best handled
by easing your foot off the accelerator pedal.
SeeTraction Control System (TCS) on page 4-5
andStabiliTrak
®System on page 4-7.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 Antilock Brake System (ABS) helps
avoid only the braking skid.
4-11

Off-Road Driving
This off-road guide is meant to provide advice for
when you drive your vehicle off paved roads. Also,
seeBraking on page 4-3.
Off-road driving can be great fun. But it does have
some denite hazards. The greatest of these is
the terrain itself.
The airbag system is designed to work properly
under a wide range of conditions, including off-road
usage. Observe safe driving speeds, especially on
rough terrain. As always, wear your safety belt.
“Off-roading” means you have left the great North
American road system behind. Traffic lanes are
not marked. Curves are not banked. There are no
road signs. Surfaces can be slippery, rough, uphill or
downhill. In short, you have gone right back to nature.
Off-road driving involves some new skills. And that
is why it is very important that you read this guide.
You will nd many driving tips and suggestions.
These will help make your off-road driving safer
and more enjoyable.
Before You Go Off-Roading
There are some things to do before you go out.
For example, be sure to have all necessary maintenance
and service work done. Check to make sure all
underbody shields are properly attached. Make sure
any equipment you may need — rst aid kit, cell phone,
ashlight, etc. — is securely stored in the vehicle. Be sure
you read all the information about your four-wheel-drive
vehicle in this manual. Is there enough fuel? Is the spare
tire fully inated? Are the uid levels up where they
should be? What are the local laws that apply to
off-roading where you will be driving? If you do not
know, you should check with law enforcement people
in the area. Will you be on someone’s private land?
If so, be sure to get the necessary permission.
4-12

Loading Your Vehicle for
Off-Road Driving
{CAUTION:
Cargo on the load oor piled higher than
the seatbacks can be thrown forward during
a sudden stop. You or your passengers
could be injured. Keep cargo below the
top of the seatbacks.
Unsecured cargo on the load oor can be
tossed about when driving over rough
terrain. You or your passengers can be
struck by ying objects. Secure the cargo
properly.
Heavy loads on the roof raise the vehicle’s
center of gravity, making it more likely to
roll over. You can be seriously or fatally
injured if the vehicle rolls over. Put heavy
loads inside the cargo area, not on the roof.
Keep cargo in the cargo area as far forward
and low as possible.There are some important things to remember about
how to load your vehicle.
The heaviest things should be on the load oor and
forward of your rear axle. Put heavier items in the
rear area, as far forward as you can.
Be sure the load is secured properly, so driving on
the off-road terrain does not toss things around.
You will nd other important information in this manual.
SeeLoading Your Vehicle on page 4-42andTires
on page 5-54.
4-13

Environmental Concerns
Off-road driving can provide wholesome and satisfying
recreation. However, it also raises environmental
concerns. We 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 open res (where permitted),
camp stoves, and lanterns.
Never park your vehicle over dry grass or other
combustible materials that could catch re 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 is 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 will want to
know how to use it properly.
High Mobility Characteristics
Your vehicle has a 10 inch (25.4 cm) running ground
clearance (A), a 9 inch (22.8 cm) axle to ground
clearance (B), and a low center of gravity.
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