2007 HUMMER H3 Owners Manual

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: 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 241
andStabiliTrak
®System on page 244.
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.
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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.
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 238.
Off-road driving can be great fun. But it does have
some denite hazards. The greatest of these is
the terrain itself.
“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.
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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 289
andTires on page 367.
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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
The HUMMER H3 has a 10 inch (25.4 cm)
running ground clearance (A) and a 9 inch
(22.8 cm) axle to ground clearance (B) while
maintaining a low silhouette and a low center
of gravity.
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The HUMMER H3 has an approximate approach
angle (A) of 37.5 degrees and a departure
angle (B) of 35.5 degrees, depending on
suspension packages.
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Design specications required a minimum
gradeability of 60% (31 degrees) slope, with the
vehicle fully loaded, on high friction surfaces
with maximum vehicle speed not to exceed
6 mph (9.7 km/h). The vehicle is expected to
traverse this grade only for short durations.
Never stop and idle the vehicle or park it on
this grade.Also, your vehicle should be able to traverse a
40% (22 degrees) side slope at 6 mph (9.7 km/h)
while fully loaded on high friction surfaces.
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Your vehicle can climb a 16 inch (40.6 cm) vertical
step. Step climbing is best done by approaching
the step at an angle rather than straight on.
Brake and Accelerator Operation
Techniques for Off-Road Driving
For logs, walls, rocks, severe ditches,
hills, sand, etc.
1. Bring the vehicle to a complete stop.
Do not rev the engine.
2. Select the proper transmission and transfer
case gear range; usually FIRST (1) gear,
Four-Wheel-Low Lock for such obstacles.
3. If wheel spin is experienced, maintain steady
throttle, with your foot off the brake pedal,
to allow the Traction Control System (TCS) to
control the wheel spin. TCS will not operate
if the brakes are applied, even slightly.
4. If wheel spin cannot be controlled by the
system, fully press the brake pedal with
your left foot so all wheel spin is halted.
5. Back away from the obstacle so that a
new approach can be tried.
6. As the rst wheel crosses the obstacle,
be prepared to alternate the brake and
accelerator pedal to maintain control and
avoid tire drop-off from obstacles. Repeat
this process for the other wheels.
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For mounds, washouts, loose up-hill
slopes, ditches, etc.
When wheel spin occurs as the vehicle is moving,
the driver may notice a slight shaking or shuddering
of the vehicle. This should be stopped as soon as
possible to prevent damage to vehicle components.
This is the indication that a loss of traction is
occurring on this terrain. The operator should:
1. Reduce speed and apply the brakes.
2. Assess the terrain properly and adjust vehicle
speed and gear ranges accordingly:
Four-Wheel High position for higher speeds
and Four-Wheel-Low Lock for more torque and
lower speeds. Transmission FIRST (1) gear
is generally recommended.
3. Apply slight pressure to the brake when the
shaking or shuddering sensation is felt,
keeping the vehicle moving in a controlled
manner.
4. Be prepared to alternate between braking and
accelerating through the adverse terrain.
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.
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