2008 HUMMER H3 tow

Automatic Transmission Operation
The automatic transmission has a shift lever on the
console.
It features an electronic shift position indicator within
the instrument cluster. This display must be powered
anytime the shift lever is capable of being moved out of
PARK (P). This means that if your key is turned off,
but not in LOCK, there will be a small current drain on
your battery which could discharge your battery over
a period of time. If you need to leave your key in
the ignition but not in LOCK for an extended period,
it is recommended that you disconnect the battery cable
from the battery to prevent discharging your battery.
There are several different positions for your shift lever.PARK (P):This position locks your rear wheels. It is
the best position to use when you start the engine
because your vehicle cannot move easily.
{CAUTION:
It is dangerous to get out of your vehicle if
the shift lever is not fully in PARK (P) with the
parking brake rmly set. Your vehicle can roll.
Do not leave your vehicle when the engine is
running unless you have to. If you have left the
engine running, the vehicle can move suddenly.
You or others could be injured. To be sure your
vehicle will not move, even when you are on
fairly level ground, always set your parking
brake and move the shift lever to PARK (P).
SeeShifting Into PARK (P) (Automatic
Transmission) on page 2-33. If you are pulling a
trailer, seeTowing a Trailer on page 4-50.
Make sure the shift lever is fully in PARK (P)
before starting the engine. Your vehicle has an
automatic transmission shift lock control system.
You must fully apply your regular brakes rst and
then press the shift lever button before you can
shift from PARK (P) when the ignition key is in ON.
2-23

DRIVE (D):This position is for normal driving.
It provides the best fuel economy for your vehicle.
If you need more power for passing, and you are:
Going less than about 35 mph (55 km/h),
push your accelerator pedal about halfway down.
Going about 35 mph (55 km/h) or more,
push the accelerator all the way down.
Downshifting the transmission in slippery road conditions
could result in skidding, see “Skidding” underLoss of
Control on page 4-10.
DRIVE (D) can be used when towing a trailer. You may
want to shift the transmission to THIRD (3) or, if
necessary, a lower gear if the transmission shifts too
often under heavy loads and/or hilly conditions.
THIRD (3):This position is also used for normal
driving. However it reduces vehicle speed more than
DRIVE (D) without using your brakes. You might
choose THIRD (3) instead of DRIVE (D) when driving
on hilly, winding roads, when towing a trailer, so there
is less shifting between gears and when going down
a steep hill.SECOND (2): This position reduces vehicle speed
even more than THIRD (3) without using your brakes.
You can use SECOND (2) on hills. It can help
control your speed as you go down steep mountain
roads, but then you would also want to use your
brakes off and on.
FIRST (1): This position reduces vehicle speed even
more than SECOND (2) without using your brakes.
You can use it on very steep hills, or in deep snow or
mud. If the shift lever is put in FIRST (1) while the
vehicle is moving forward, the transmission will not shift
into rst gear until the vehicle is going slowly enough.
Notice:Spinning the tires or holding the vehicle
in one place on a hill using only the accelerator
pedal may damage the transmission. The repair will
not be covered by your warranty. If you are stuck,
do not spin the tires. When stopping on a hill,
use the brakes to hold the vehicle in place.
2-25

Transfer Case Buttons
The transfer case buttons are located to the right of the
instrument panel cluster. Use these switches to shift
into and out of the different Full-Time Four-Wheel
Drive modes.
You can choose between four modes:
4
m(Four-Wheel High):This setting is used for driving
in most street and highway situations. You can also
use this setting for light or variable off-road conditions.
N (NEUTRAL):Shift the vehicle’s transfer case to
NEUTRAL only when towing your vehicle. See
Recreational Vehicle Towing on page 4-48orTowing
Your Vehicle on page 4-48for more information.Notice:Driving on pavement in Four-Wheel
High Lock or Four Wheel Low Lock for extended
periods may cause premature wear on your vehicle’s
powertrain and tires. Do not drive in Four-Wheel
High Lock or Four-Wheel Low Lock on pavement for
extended periods.
4
mQ(Four-Wheel-High Lock):Use this mode
when you need extra traction in most off-road situations
such as sand, mud, snow or level, rocky trails.
Notice:Operating your vehicle in
Four-Wheel-Low Lock above 30 mph (48 km/h) for
any extended period of time could cause damage
to the transfer case. Do not operate your vehicle
in Four-Wheel-Low Lock above 30 mph (48 km/h) for
extended periods.
4
nQ(Four-Wheel-Low Lock):This mode delivers
extra torque to all four wheels and is used for extreme
off-road conditions. You might choose 4-Wheel-Low
Lock if you are driving in off-road situations, such as,
deep sand, mud, or snow and climbing or descending
steep hills.
If the vehicle has a locking rear axle, when in this mode
you can also choose to lock the rear axle for additional
traction in extreme off-road situations. SeeLocking Rear
Axle on page 4-6.
2-28

Parking Brake
The parking brake pedal is
located to the left of the
regular brake pedal,
near the driver’s door.
To set the parking brake, hold the regular brake pedal
down with your right foot. Push the parking brake
pedal down to its fully-applied position with your
left foot.
A chime will activate and the brake warning light,
located on the instrument panel, will ash when the
parking brake is applied and the vehicle is moving
at least 3 mph (5 km/h) for at least three seconds.
The chime will deactivate and the light will turn off
when the parking brake is set and the vehicle is
moving below 3 mph (5 km/h). SeeBrake System
Warning Light on page 3-33.To release the parking brake, hold the regular brake
pedal down. Pull the bottom edge of the lever, located
above the parking brake pedal, with the parking brake
symbol, directly rearward to release the parking brake.
If the ignition is on when the parking brake is released,
the brake system warning light will go off.
Notice:Driving with the parking brake on can
overheat the brake system and cause premature
wear or damage to brake system parts. Make sure
that the parking brake is fully released and the brake
warning light is off before driving.
If you are towing a trailer and are parking on any hill,
seeTowing a Trailer on page 4-50.
2-32

Shifting Into PARK (P)
(Automatic Transmission)
{CAUTION:
It can be dangerous to get out of your vehicle
if the shift lever is not fully in PARK (P) with
the parking brake rmly set. Your vehicle
can roll. If you have left the engine running,
the vehicle can move suddenly. You or others
could be injured. To be sure your vehicle will
not move, even when you are on fairly level
ground, use the steps that follow. If you
are pulling a trailer, seeTowing a Trailer
on page 4-50.
1. Hold the brake pedal down with your right foot
and set the parking brake.
SeeParking Brake on page 2-32for more
information.
{CAUTION:
With all-wheel drive, your vehicle will be free to
roll — even if your shift lever is in PARK (P) — if
your transfer case is in NEUTRAL. So, be sure
the transfer case is in a drive gear, four-wheel
high (4H) or four-wheel low (4L) — not in
NEUTRAL.
2. Move the shift lever into PARK (P) by pressing
the shift lever button and moving the lever as
far forward as it will go.
3. Turn the ignition key to LOCK/OFF.
4. Remove the key and take it with you. If you can
leave your vehicle with the key, your vehicle is
in PARK (P).
2-33

Shifting Out of PARK (P)
(Automatic Transmission)
Your vehicle has an automatic transaxle shift lock
control system. You have to fully apply your regular
brakes before you can shift from PARK (P) when
the ignition is RUN. SeeAutomatic Transmission
Operation on page 2-23.
The shift lock control system is designed to do the
following:
Prevent the ignition key from being removed
unless the shift lever is in PARK (P).
Prevent movement of the shift lever out of
PARK (P), unless the ignition is in ON/RUN
and the regular brake pedal is applied.
The shift lock control system is always functional
except in the case of a dead battery or low voltage
(less than 9 V) battery.
If your vehicle has an uncharged battery or a battery
with low voltage, try charging or jump starting the
battery. SeeJump Starting on page 5-42for more
information.To shift out of PARK (P) use the following:
1. Apply the brake pedal.
2. Move the shift lever to the desired position.
If you still are unable to shift out of PARK (P):
1. Ease the pressure on the shift lever.
2. While holding down the brake pedal, push the
shift lever all the way into PARK (P)
3. Move the shift lever to the desired position.
If you are still having a problem shifting, then have
your vehicle serviced soon.Parking Your Vehicle
(Manual Transmission)
Your vehicle has a manual transmission. Before you
get out of your vehicle, move the shift lever into
REVERSE (R), and rmly apply the parking brake.
Once the shift lever has been placed into REVERSE (R)
with the clutch pedal pressed in, turn the ignition key
to LOCK, remove the key and release the clutch.
If you are parking on a hill, or if your vehicle is pulling
a trailer, seeTowing a Trailer on page 4-50.
2-35

Running the Engine While Parked
It is better not to park with the engine running.
But if you ever have to, here are some things to know.
{CAUTION:
Idling the engine with the climate control
system off could allow dangerous exhaust into
your vehicle. See the earlier caution under
Engine Exhaust on page 2-36.
Also, idling in a closed-in place can let deadly
carbon monoxide (CO) into your vehicle
even if the climate control fan is at the highest
setting. One place this can happen is a garage.
Exhaust — with CO — can come in easily.
NEVER park in a garage with the engine
running.
Another closed-in place can be a blizzard.
SeeWinter Driving on page 4-35.
{CAUTION:
It can be dangerous to get out of your vehicle
if the automatic transmission shift lever is not
fully in PARK (P) with the parking brake rmly
set. Your vehicle can roll. Do not leave your
vehicle when the engine is running unless you
have to. If you have left the engine running,
the vehicle can move suddenly. You or others
could be injured. To be sure your vehicle will
not move, even when it is on fairly level
ground, always set the parking brake and
move the automatic transmission shift lever
to PARK (P), or the manual transmission shift
lever to NEUTRAL.
Follow the proper steps to be sure your vehicle will
not move. SeeShifting Into PARK (P) (Automatic
Transmission) on page 2-33andParking Your Vehicle
(Manual Transmission) on page 2-35.
If you are pulling a trailer with your vehicle, see
Towing a Trailer on page 4-50.
2-37

Cleaning the Mirror
Use a paper towel or similar material dampened with
glass cleaner. Do not spray glass cleaner directly on
the mirror as that could cause the liquid cleaner to enter
the mirror housing.
Automatic Dimming Rearview Mirror
with Compass and Temperature
Display
Your vehicle may have this mirror. When on, an
automatic dimming mirror will dim to the proper level to
minimize glare from lights behind you after dark.
The mirror also includes a dual display in the upper
right corner of the mirror with the compass reading and
the outside temperature.
Yb:Briey press this button to turn the display on
or off.
Your vehicle may also have a Rear Vision Camera.
SeeRear Vision Camera on page 2-44for more
information.
Temperature Display
The temperature can be displayed by pressing the
compass/temperature button. Pressing the compass/
temperature button once briey, will toggle the display
reading on and off. To alternate the temperature reading
between Fahrenheit and Celsius, press and hold
the compass/temperature button for approximately
three seconds until the display blinks F and C. After
approximately ve seconds of inactivity, the display will
stop blinking and display the last selection made.
If an abnormal reading is displayed, see your
dealer/retailer.
Automatic Dimming Mirror Operation
O
:Press this button to turn the automatic dimming
feature on or off. The indicator light to the left of the
button will turn on to indicate when the feature is on.
Once the mirror is turned off, it will remain off until it is
turned back on, or until the vehicle is restarted.
Compass Operation
Press the compass/temperature button once briey
to turn the display on or off.
2-41