trailer HUMMER H2 2008 Owners Manual

Starting and Operating Your
Vehicle
New Vehicle Break-In
Notice:Your vehicle does not need an elaborate
break-in. But it will perform better in the long run if
you follow these guidelines:
Keep your speed at 55 mph (88 km/h) or less for
the rst 500 miles (805 km).
Do not drive at any one constant speed, fast or
slow, for the rst 500 miles (805 km). Do not
make full-throttle starts. Avoid downshifting to
brake or slow the vehicle.
Avoid making hard stops for the rst 200 miles
(322 km) or so. During this time the new brake
linings are not yet broken in. Hard stops
with new linings can mean premature wear and
earlier replacement. Follow this breaking-in
guideline every time you get new brake linings.
Do not tow a trailer during break-in. SeeTowing
a Trailer on page 4-55for the trailer towing
capabilities of your vehicle and more
information.
Following break-in, engine speed and load can be
gradually increased.
Ignition Positions
Use the key to turn the
ignition switch to four
different positions.
In order to shift out of PARK (P), ignition must be in the
ON/RUN or ACC/ACCESSORY and the regular brake
pedal must be applied.
A (LOCK/OFF):This position locks the ignition and
transmission. It is a theft-deterrent feature. The key
can only be removed when the ignition is turned
to LOCK/OFF.
2-28

Automatic Transmission Operation
Your vehicle has a Hydra-Matic®6L80 automatic
transmission, and has an electronic shift position
indicator within the instrument panel cluster. This display
comes on when the ignition key is turned to the
ON/RUN position.
There are several different positions for the shift lever.
PARK (P):This position locks the rear wheels. It is the
best position to use when you start your engine
because your vehicle cannot move easily.
When parked on a hill, especially when the vehicle
has a heavy load, you may notice an increase in the
effort to shift out of PARK (P). See Torque Lock
(Automatic Transmission) underShifting Into PARK (P)
on page 2-41for more information.{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) on
page 2-41. If you are pulling a trailer, see
Towing a Trailer on page 4-55.
REVERSE (R):Use this gear to back up.
Notice:Shifting to REVERSE (R) while your vehicle
is moving forward could damage the transmission.
The repairs would not be covered by your warranty.
Shift to REVERSE (R) only after your vehicle is
stopped.
2-32

To rock your vehicle back and forth to get out of snow,
ice, or sand without damaging the transmission, see
If Your Vehicle is Stuck in Sand, Mud, Ice, or Snow on
page 4-39.
NEUTRAL (N):In this position, the engine does not
connect with the wheels. To restart when you are
already moving, use NEUTRAL (N) only. Also, use
NEUTRAL (N) when your vehicle is being towed.
{CAUTION:
Shifting into a drive gear while the engine is
running at high speed is dangerous. Unless
your foot is rmly on the brake pedal, your
vehicle could move very rapidly. You could
lose control and hit people or objects. Do not
shift into a drive gear while your engine is
running at high speed.
Notice:Shifting out of PARK (P) or NEUTRAL (N)
with the engine running at high speed may damage
the transmission. The repairs would not be covered
by your warranty. Be sure the engine is not running
at high speed when shifting your vehicle.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 the
accelerator pedal about halfway down.
Going about 35 mph (55 km/h) or more, push the
accelerator all the way down.
By doing this, the vehicle shifts down to the next gear
and has more power.
DRIVE (D) can be used when towing a trailer, carrying a
heavy load, driving on steep hills, or for off-road
driving. You may want to shift the transmission to a
lower gear selection if the transmission shifts too often.
Downshifting the transmission in slippery road
conditions could result in skidding, see Skidding under
Loss of Control on page 4-12.
MANUAL MODE (M):This position lets drivers select
the range of gears appropriate for current driving
conditions. If your vehicle has this feature, see Driver
Shift Control (DSC) later in this section.
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.
2-33

Driver Shift Control (DSC)
Your vehicle has a Driver
Shift Control (DSC).
The DSC controls the
vehicle’s transmission
and vehicle speed while
driving down hill or towing
a trailer by allowing you
to select a desired range
of gears.
To use this feature:
1. Move the shift lever to the MANUAL MODE (M).
This will force a downshift from the current gear,
for gears 3 through 6.
2. Press the (+) plus or (−) minus button on the left
side of the steering wheel, to select the desired
range of gears for your current driving conditions.When in the MANUAL MODE (M) a number will display
next to the M, indicating the maximum available
gear. The DIC display will show the message MANUAL
SHIFT on the rst line and the maximum available
gear will be displayed on the second line. SeeDriver
Information Center (DIC) on page 3-49andDIC
Operation and Displays (Using DIC Buttons) on
page 3-49orDIC Operation and Displays (Using Trip
Odometer Reset Stem) on page 3-54for more
information. The number displayed in the DIC is the
highest gear available. The transmission will be limited
to the gear selected and lower gears. Shifting will
occur normally while driving, however the cluster will
continue to display the maximum available gear.
Higher gears will not be available unless the selection
is changed to include higher gears using the (+) plus
button.
Grade Braking is not available when the Driver Shift
Control is active. SeeTow/Haul Mode on page 2-36and
Towing a Trailer on page 4-55for more information.
While using the DSC, cruise control and the tow/haul
mode can be used.
2-35

Tow/Haul Mode
Your vehicle is equipped
with a tow/haul mode.
The button is located on
the instrument panel
to the right of the
steering wheel.
You can use this feature to assist when towing or
hauling a heavy load. See “Tow/Haul Mode” under
Towing a Trailer on page 4-55for more information.
Full-Time Four-Wheel Drive
The transfer case on your Full-Time Four-Wheel Drive
vehicle is designed to constantly send the engine’s
driving power to all four wheels for extra traction.
To get the most out of Full-Time Four-Wheel Drive,
you must be familiar with its operation.
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.
Transfer Case Dial
The transfer case dial is
located to the right of the
instrument panel cluster.
Use this switch to shift into
and out of the different
Full-Time Four-Wheel
Drive modes.
The transfer case is a part of the Full-Time Four-Wheel
Drive system and allows the following four different
modes of operation:
4
m(Full-Time Four-Wheel Drive):This setting is used
for driving in most street and highway situations.
It can be used for light or variable off-road conditions.
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.
4
nQ(Four-Wheel-Low Lock):This mode delivers
extra torque to all four wheels and is used for extreme
off-road conditions. Choose Four-Wheel-Low Lock while
driving off-road in deep sand, mud, or snow and climbing
or descending steep hills.
2-36

Shifting Out of NEUTRAL
To shift out of NEUTRAL do the following:
1. Set the parking brake and apply the regular brake
pedal.
2. Shift the transmission to NEUTRAL (N) and turn
the ignition to RUN with the engine off.
3. Turn the transfer case dial to Four-Wheel High,
Four-Wheel High Lock or Four-Wheel Low Lock.
After the transfer case has shifted out of NEUTRAL
the NEUTRAL light will go out.
4. Release the parking brake prior to moving the
vehicle.
Notice:Shifting the transmission into gear before
the requested mode indicator light has stopped
ashing could damage the transfer case. To help
avoid damaging your vehicle, always wait for the
mode indicator lights to stop ashing before shifting
the transmission into gear.
5. Start the engine and shift the transmission to the
desired position.
Parking Brake
To set the parking brake, hold the regular brake pedal
down with your right foot. Push down the parking
brake pedal with your left foot.
A chime will activate and
the warning light 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.
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, 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 4-55.
2-40

Shifting Into PARK (P)
{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 4-55.
1. Hold the brake pedal down with your foot and set
the parking brake. SeeParking Brake on page 2-40
for more information.
2. Move the shift lever into PARK (P) by pressing the
button on the shift lever and pushing the lever all
the way toward the front of the vehicle.
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).
Leaving Your Vehicle With the
Engine Running
{CAUTION:
It can be dangerous to leave your vehicle with
the engine running. Your vehicle could move
suddenly if the shift lever is not fully in
PARK (P) with the parking brake rmly set.
And, if you leave the vehicle with the engine
running, it could overheat and even catch re.
You or others could be injured. Do not leave
your vehicle with the engine running.
If you have to leave your vehicle with the engine
running, be sure your vehicle is in PARK (P) and your
parking brake is rmly set before you leave it. After you
have moved the shift lever into PARK (P), hold the
regular brake pedal down. Then, see if you can move
the shift lever away from PARK (P) without rst pressing
the button on the console shift lever. If you can, it
means that the shift lever was not fully locked into
PARK (P).
2-41

{CAUTION:
Full-time four-wheel drive vehicles with the
transfer case in NEUTRAL will allow the
vehicle to roll, even if the shift lever is in
PARK (P). So, be sure the transfer case is in a
drive gear — not in NEUTRAL. Always set the
parking brake.
Follow the proper steps to be sure your vehicle will not
move. SeeShifting Into PARK (P) on page 2-41.
If you are pulling a trailer, seeTowing a Trailer on
page 4-55.
Mirrors
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 2-50.
2-45

Notice:The spare tire extends farther away from
rear of the vehicle than the trailer hitch shown
on rear vision camera display. Your spare tire could
hit an object even though there appears to be
enough distance on the display between the trailer
hitch and objects behind you causing vehicle or
property damage. Do not use this system to judge
the distance between the spare tire and objects
behind you.
When the System Does Not Seem To
Work Properly
The rear vision camera system may not work properly
or display a clear image in the following situations:
In the dark.
When the sun or the beam of headlights is shining
directly into the camera lens.
If ice, snow, mud, or anything else builds up on the
camera lens. Clean the lens, rinse it with water, and
wipe it with a soft cloth.
If the back of the vehicle is in an accident, the
position and mounting angle of the camera may
change or the camera may be affected. Be sure to
have the camera and its position and mounting angle
checked at your dealer.
Extreme high or low temperatures or extreme
temperature changes can affect the image displayed.
OnStar®System
OnStar uses several innovative technologies and live
advisors to provide you with a wide range of safety,
security, information, and convenience services. If your
airbags deploy, the system is designed to make an
automatic call to OnStar Emergency advisors who can
request emergency services be sent to your location.
If you lock your keys in the vehicle, call OnStar at
1-888-4-ONSTAR and they can send a signal to unlock
your doors. If you need roadside assistance, press
the OnStar button and they can contact Roadside
Service for you.
OnStar service is provided to you subject to the
OnStar Terms and Conditions. You may cancel your
OnStar service at any time by contacting OnStar.
2-53

This light comes on, as a check to show it is working,
when the ignition is turned ON/RUN but the engine is not
running. If the light does not come on, have it repaired.
This light also comes on during a malfunction in
one of two ways:
Light Flashing— A misre condition has been
detected. A misre increases vehicle emissions
and could damage the emission control system
on your vehicle. Diagnosis and service might
be required.
Light On Steady— An emission control system
malfunction has been detected on your vehicle.
Diagnosis and service might be required.
If the Light is Flashing
The following can prevent more serious damage
to your vehicle:
Reduce vehicle speed.
Avoid hard accelerations.
Avoid steep uphill grades.
If you are towing a trailer, reduce the amount
of cargo being hauled as soon as it is possible.If the light stops ashing and remains on steady,
see “If the Light Is On Steady” following.
If the light continues to ash, when it is safe to do so,
stop the vehicle. Find a safe place to park the vehicle.
Turn the ignition off, wait at least 10 seconds, and restart
the engine. If the light remains on steady, see “If the
Light Is On Steady” following. If the light is still ashing,
follow the previous steps and see your dealer/retailer
for service as soon as possible.
If the Light Is On Steady
You might be able to correct the emission system
malfunction by considering the following:
Did you recently put fuel into your vehicle?
If so, reinstall the fuel cap, making sure to fully install the
cap. SeeFilling the Tank on page 5-7. The diagnostic
system can determine if the fuel cap has been left off or
improperly installed. A loose or missing fuel cap allows
fuel to evaporate into the atmosphere. A few driving trips
with the cap properly installed should turn the light off.
Did you just drive through a deep puddle of water?
If so, your vehicle’s electrical system might be wet. The
condition is usually corrected when the electrical system
dries out. A few driving trips should turn the light off.
3-43