engine HUMMER H3 2009 Workshop Manual

Driving in Water
{CAUTION
Driving through rushing water can
be dangerous. Deep water can
sweep your vehicle downstream
and you and your passengers
could drown. If it is only shallow
water, it can still wash away the
ground from under your tires, and
you could lose traction and roll
the vehicle over. Do not drive
through rushing water.
Heavy rain can mean ash ooding,
and ood waters demand extreme
caution.Find out how deep the water is
before driving through it. Do not
try it if it is deep enough to cover
the wheel hubs, axles, or exhaust
pipe — you probably will not get
through. Deep water can damage the
axle and other vehicle parts. The
vehicle is capable of depths up to
20 inches (50 cm). Know how to
judge whether the water is deeper
than this before proceeding into it.
If the water is not too deep, drive
slowly through it. At faster speeds,
water splashes on the ignition
system and the vehicle can stall.
Stalling can also occur if you get the
tailpipe under water. If the tailpipe
is under water, you will never
be able to start the engine. When
going through water, remember that
when the brakes get wet, it might
take longer to stop. SeeDriving
in Rain and on Wet Roads on
page 4-29.
After Off-Road Driving
Remove any brush or debris that
has collected on the underbody,
chassis, or under the hood. These
accumulations can be a re hazard.
After operation in mud or sand,
have the brake linings cleaned and
checked. These substances can
cause glazing and uneven braking.
Check the engine and oil coolers
for mud accumulation. Thoroughly
and carefully clean these devices to
allow proper cooling. Check the
body structure, steering, suspension,
wheels, tires, and exhaust system
for damage and check the fuel lines
and cooling system for any
leakage.
The vehicle requires more frequent
service due to off-road use.
Refer to the Maintenance Schedule
for additional information.
Driving Your Vehicle 4-27

Before Leaving on a
Long Trip
To prepare your vehicle for a long
trip, consider having it serviced
by your dealer/retailer before
departing.
Things to check on your own
include:
Windshield Washer Fluid:
Reservoir full? Windows
clean — inside and outside?
Wiper Blades:In good shape?
Fuel, Engine Oil, Other Fluids:All
levels checked?
Lamps:Do they all work and are
lenses clean?
Tires:Are treads good? Are tires
inated to recommended
pressure?
Weather and Maps:Safe to
travel? Have up-to-date maps?
Highway Hypnosis
Always be alert and pay attention
to your surroundings while driving. If
you become tired or sleepy, nd
a safe place to park your vehicle
and rest.
Other driving tips include:
Keep the vehicle well ventilated.
Keep interior temperature cool.
Keep your eyes moving — scan
the road ahead and to the sides.
Check the rearview mirror and
vehicle instruments often.
Hill and Mountain Roads
Driving on steep hills or through
mountains is different than driving
on at or rolling terrain. Tips for
driving in these conditions include:
Keep the vehicle serviced
and in good shape.
Check all uid levels and brakes,
tires, cooling system, and
transmission.
Going down steep or long hills,
shift to a lower gear.
{CAUTION
If you do not shift down, the
brakes could get so hot that they
would not work well. You would
then have poor braking or even
none going down a hill. You could
crash. Shift down to let the engine
assist the brakes on a steep
downhill slope.
4-30 Driving Your Vehicle

{CAUTION
Coasting downhill in N (Neutral)
or with the ignition off is
dangerous. The brakes will have
to do all the work of slowing down
and they could get so hot that
they would not work well. You
would then have poor braking or
even none going down a hill. You
could crash. Always have the
engine running and the vehicle in
gear when going downhill.
Stay in your own lane. Do not
swing wide or cut across the
center of the road. Drive at
speeds that let you stay in your
own lane.
Top of hills: Be alert — something
could be in your lane (stalled car,
accident).
Pay attention to special road
signs (falling rocks area, winding
roads, long grades, passing or
no-passing zones) and take
appropriate action.
SeeOff-Road Driving on page 4-13
for information about driving
off-road.
Winter Driving
Driving on Snow or Ice
Drive carefully when there is snow
or ice between the tires and the
road, creating less traction or grip.
Wet ice can occur at about 32°F
(0°C) when freezing rain begins to
fall, resulting in even less traction.
Avoid driving on wet ice or in
freezing rain until roads can be
treated with salt or sand.
Drive with caution, whatever the
condition. Accelerate gently
so traction is not lost. Accelerating
too quickly causes the wheelsto spin and makes the surface
under the tires slick, so there is even
less traction.
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.
TheTraction Control System (TCS)
on page 4-7improves the ability
to accelerate on slippery roads, but
slow down and adjust your driving
to the road conditions. When driving
through deep snow, turn off the
traction control system to help
maintain vehicle motion at lower
speeds.
TheAntilock Brake System (ABS)
on page 4-5improves vehicle
stability during hard stops on a
slippery roads, but apply the brakes
sooner than when on dry pavement.
Driving Your Vehicle 4-31

Allow greater following distance on
any slippery road and watch for
slippery spots. Icy patches
can occur on otherwise clear roads
in shaded areas. The surface of
a curve or an overpass can remain
icy when the surrounding roads
are clear. Avoid sudden steering
maneuvers and braking while on ice.
Turn off cruise control, if equipped,
on slippery surfaces.
Blizzard Conditions
Being stuck in snow can be in a
serious situation. Stay with the
vehicle unless there is help nearby.
If possible, use theRoadside
Service on page 7-6. To get help
and keep everyone in the vehicle
safe:
Turn on theHazard Warning
Flashers on page 3-5.
Tie a red cloth to an outside
mirror.
{CAUTION
Snow can trap engine exhaust
under the vehicle. This may cause
exhaust gases to get inside.
Engine exhaust contains carbon
monoxide (CO) which cannot be
seen or smelled. It can cause
unconsciousness and even death.
If the vehicle is stuck in the snow:
Clear away snow from
around the base of your
vehicle, especially any that is
blocking the exhaust pipe.
Check again from time to
time to be sure snow does
not collect there.
Open a window about two
inches (5 cm) on the side of
the vehicle that is away from
the wind to bring in fresh air.
Fully open the air outlets on
or under the instrument
panel.
(Continued)
CAUTION (Continued)
Adjust the Climate Control
system to a setting that
circulates the air inside the
vehicle and set the fan speed
to the highest setting. See
Climate Control System in the
Index.
For more information about
carbon monoxide, seeEngine
Exhaust on page 2-31.
Snow can trap exhaust gases
under your vehicle. This can
cause deadly CO (carbon
monoxide) gas to get inside. CO
could overcome you and kill you.
You cannot see it or smell it, so
you might not know it is in your
vehicle. Clear away snow from
around the base of your vehicle,
especially any that is blocking the
exhaust.
4-32 Driving Your Vehicle

Run the engine for short periods
only as needed to keep warm,
but be careful.
To save fuel, run the engine for
only short periods as needed to
warm the vehicle and then shut the
engine off and close the window
most of the way to save heat.
Repeat this until help arrives
but only when you feel really
uncomfortable from the cold. Moving
about to keep warm also helps.
If it takes some time for help to
arrive, now and then when you run
the engine, push the accelerator
pedal slightly so the engine
runs faster than the idle speed. This
keeps the battery charged to
restart the vehicle and to signal for
help with the headlamps. Do
this as little as possible to save fuel.If Your Vehicle is
Stuck in Sand, Mud,
Ice, or Snow
Slowly and cautiously spin the
wheels to free the vehicle when
stuck in sand, mud, ice, or snow.
SeeRocking Your Vehicle to Get It
Out on page 4-34.
If the vehicle has a traction system,
it can often help to free a stuck
vehicle. Refer to the vehicle’s
traction system in the Index. If stuck
too severely for the traction
system to free the vehicle, turn the
traction system off and use the
rocking method.
{CAUTION
If you let your vehicle’s tires spin
at high speed, they can explode,
and you or others could be
injured. The vehicle can overheat,
causing an engine compartment
re or other damage. Spin the
wheels as little as possible and
avoid going above 35 mph
(55 km/h) as shown on the
speedometer.
For information about using tire
chains on the vehicle, seeTire
Chains on page 5-65.
Driving Your Vehicle 4-33

Use the following procedure to tow
the vehicle:
1. Put the transmission in P (Park)
for an automatic transmission or
in 1 (First) for a manual
transmission.
2. Turn the engine off, but leave the
ignition in ACC/ACCESSORY.
3. Firmly set the parking brake.
4. Securely attach the vehicle being
towed to the tow vehicle.
{CAUTION
Shifting a full-time
four-wheel-drive vehicle’s
transfer case into N (Neutral)
can cause the vehicle to roll
even if the automatic transmission
is in P (Park) or the manual
transmission is in any gear. You
or others could be injured. Make
sure the parking brake is rmly
set before the transfer case is
shifted to N (Neutral).5. Shift the transfer case to
N (Neutral). SeeFull-Time
Four-Wheel Drive on page 2-24
for the proper procedure to
select the N (Neutral) position for
the vehicle.
6. Release the parking brake only
after the vehicle being towed is
rmly attached to the tow vehicle.
7. Make sure the ignition is in
ACC/ACCESSORY.
When towing the vehicle for
extended periods of time, start the
vehicle as often as possible to
prevent battery drain. This should
only be done when the tow
vehicle is parked.
After towing, see “Shifting Out of
NEUTRAL” underFull-Time
Four-Wheel Drive on page 2-24.
Dolly Towing
Notice:Dolly towing the vehicle
will damage drivetrain
components. Do not dolly tow the
vehicle.
The vehicle cannot be dolly towed.
If the vehicle must be towed
behind another vehicle, use the
dinghy towing procedure explained
previously.
Driving Your Vehicle 4-41

Do not tow a trailer at all during
the rst 500 miles (800 km) the
new vehicle is driven. The
engine, axle or other parts could
be damaged.
Then, during the rst 500 miles
(800 km) that a trailer is towed,
do not drive over 50 mph
(80 km/h) and do not make starts
at full throttle. This helps the
engine and other parts of
the vehicle wear in at the
heavier loads.
Vehicles with an automatic
transmissions can tow in
D (Drive). Shift the transmission
to a lower gear if the
transmission shifts too often
under heavy loads and/or hilly
conditions. For vehicles with
a manual transmission, it is better
not to use the highest gear.
This vehicle has a Hill Start
Assist feature, which may
be useful when the vehicle is
stopped on a grade. SeeBraking
on page 4-3for more information.
Three important considerations have
to do with weight:
The weight of the trailer
The weight of the trailer tongue
The weight on the vehicle’s tires
Weight of the Trailer
How heavy can a trailer safely be?
It depends on how the rig is
used. For example, speed, altitude,
road grades, outside temperature
and how much the vehicle is used to
pull a trailer are all important. It
can depend on any special
equipment on the vehicle, and the
amount of tongue weight the vehicle
can carry. See “Weight of the
Trailer Tongue” later in this section
for more information.
Driving Your Vehicle 4-43

Maximum trailer weight is calculated
assuming only the driver is in the
tow vehicle and it has all the
required trailering equipment. Theweight of additional optional
equipment, passengers and cargo in
the tow vehicle must be subtracted
from the maximum trailer weight.Use the following chart to determine
how much the vehicle can weigh,
based upon the vehicle model
and options.
Vehicle
Axle Ratio Maximum Trailer Weight *GCWR
H3 3.7L L5 Engine, Automatic
Transmission 4.56
4,500 lbs (2 041 kg) 9,500 lbs (4 309 kg)
3.7L L5 Engine, Manual
Transmission 4.56
3,000 lbs (1 361 kg) 8,000 lbs (3 629 kg)
5.3L V8 Engine, Automatic
Transmission 4.10
6,000 lbs (2 721 kg) 11,400 lbs (5 171 kg)
H3T 3.7L L5 Engine, Automatic
Transmission 4.56
4,400 lbs (1 996 kg) 9,500 lbs (4 309 kg)
3.7L L5 Engine, Manual
Transmission 4.56
2,900 lbs (1 315 kg) 8,000 lbs (3 629 kg)
5.3L V8 Engine, Automatic
Transmission 4.10
5,900 lbs (2 676 kg) 11,400 lbs (5 171 kg)
*The Gross Combination Weight Rating (GCWR) in the total allowable weight of the completely loaded vehicle and
trailer including any passengers, cargo, equipment and conversions. The GCWR for the vehicle should not be
exceeded.
Ask your dealer/retailer for our
trailering information or advice, or
write us at our Customer Assistance Offices. See
Customer Assistance
Offices on page 7-4 for more
information.
4-44 Driving Your Vehicle

Making Turns
Notice:Making very sharp turns
while trailering could cause
the trailer to come in contact with
the vehicle. The vehicle could
be damaged. Avoid making very
sharp turns while trailering.
When turning with a trailer, make
wider turns than normal. Do this
so the trailer won’t strike soft
shoulders, curbs, road signs, trees
or other objects. Avoid jerky or
sudden maneuvers. Signal well in
advance.
Turn Signals When Towing a
Trailer
The arrows on the instrument panel
ash whenever signaling a turn
or lane change. Properly hooked up,
the trailer lamps also ash, telling
other drivers the vehicle is turning,
changing lanes or stopping.When towing a trailer, the arrows
on the instrument panel ash
for turns even if the bulbs on the
trailer are burned out. For this
reason you may think other drivers
are seeing the signal when they
are not. It is important to check
occasionally to be sure the trailer
bulbs are still working.
Driving On Grades
Reduce speed and shift to a lower
gearbeforestarting down a long
or steep downgrade. If the
transmission is not shifted down, the
brakes might have to be used so
much that they would get hot and no
longer work well.
Vehicles with an automatic
transmission can tow in D (Drive).
Shift the transmission to a lower
gear if the transmission shifts
too often under heavy loads and/or
hilly conditions. For vehicles with
a manual transmission, it is
better not to use the highest gear.When towing at high altitude on
steep uphill grades, consider
the following: Engine coolant will
boil at a lower temperature than at
normal altitudes. If the engine is
turned off immediately after towing
at high altitude on steep uphill
grades, the vehicle may show signs
similar to engine overheating. To
avoid this, let the engine run
while parked, preferably on level
ground, with the automatic
transmission in P (Park) for a
few minutes before turning the
engine off. For vehicles with manual
transmissions, let the engine run
while parked, preferably on
level ground, with the transmission
out of gear and the parking
brake applied, for a few minutes
before turning the engine off. If the
overheat warning comes on,
seeEngine Overheating on
page 5-27.
Driving Your Vehicle 4-49

Parking on Hills
{CAUTION
Parking the vehicle on a hill with
the trailer attached can be
dangerous. If something goes
wrong, the rig could start to move.
People can be injured, and both
the vehicle and the trailer can be
damaged. When possible, always
park the rig on a at surface.
If parking the rig on a hill:
1. Press the brake pedal, but do
not shift into P (Park) yet for
vehicles with an automatic
transmission, or into gear for
vehicles with a manual
transmission. Turn the wheels
into the curb if facing downhill or
into traffic if facing uphill.2. Have someone place chocks
under the trailer wheels.
3. When the wheel chocks are in
place, release the brake pedal
until the chocks absorb the load.
4. Reapply the brake pedal.
Then apply the parking brake and
shift into P (Park) for vehicles
with an automatic transmission or
into gear for vehicles with a
manual transmission.
5. Release the brake pedal.
Leaving After Parking on
a Hill
The vehicle has a Hill Start Assist
feature, which may be useful
when stopped on a grade. See
Braking on page 4-3for more
information.
1. Apply and hold the brake pedal
while you:
start the engine,
shift into a gear, and
release the parking brake.
2. Let up on the brake pedal.
3. Drive slowly until the trailer is
clear of the chocks.
4. Stop and have someone pick up
and store the chocks.
4-50 Driving Your Vehicle