trailer HUMMER H3 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 4-50for the trailer towing
capabilities of your vehicle and more
information.
Following break-in, engine speed and load can be
gradually increased.
Ignition Positions
With the key in the ignition
switch, you can turn to
four different positions.
To shift out of PARK (P), the ignition must be in
ON/RUN and the regular brake pedal must be applied.
Notice:Using a tool to force the key from the
ignition switch could cause damage or break the key.
Use the correct key and turn the key only with your
hand. Make sure the key is all the way in. If none of
this works, then your vehicle needs service.
(A) LOCK/OFF:This position locks the ignition. It also
locks the transmission on automatic transmission
vehicles. It locks the steering wheel on manual
transmission vehicles when the key is removed. It is a
theft-deterrent feature. You will only be able to remove
your key when the ignition is turned to LOCK/OFF.
2-18

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

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

Area Displayed On Screen
The image is provided by the camera located on the
rear bumper.
The camera uses a special lens. The distance of the
image that appears on the screen differs from the actual
distance. The area displayed by the camera is limited.The camera does not display objects which are close
to either corner of the bumper or under the bumper.
The spare tire and carrier extends rearward of the rear
bumper. The area displayed on the screen may vary
according to vehicle orientation or road conditions.
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.
The following illustration shows the eld of view that
the camera provides.
2-46

Dome Lamp Override
E(Dome Lamp Override):You can use the dome
override button, located below the exterior lamps control,
to set the dome and footwell lamps to come on
automatically when a door is opened, or to remain off.
To turn the lamps off, press the button into the in
position. With the button in this position, the dome lamps
will remain off when the doors are open. To return the
lamps to automatic operation, press the button again
and return it to the out position. With the button in this
position, the dome lamps will come on when you
open a door.
Exit Lighting
With exit lighting, the interior lamps will come on when
you remove the key from the ignition. The lamps will not
come on if the dome override button is pressed in.
Reading Lamps
Your vehicle has reading lamps. Press the button
located next to the lamp to turn them on or off.
These lamps will not come on with the dome lamps.
Electric Power Management
The vehicle has Electric Power Management (EPM) that
estimates the battery’s temperature and state of
charge. It then adjusts the voltage for best performance
and extended life of the battery.
When the battery’s state of charge is low, the voltage is
raised slightly to quickly put the charge back in. When
the state of charge is high, the voltage is lowered slightly
to prevent overcharging. If the vehicle has a voltmeter
gage, you may see the voltage move up or down. This is
normal. If there is a problem, an alert will be displayed.
The battery can be discharged at idle if the electrical
loads are very high. This is true for all vehicles. This is
because the generator (alternator) may not be
spinning fast enough at idle to produce all the power
that is needed for very high electrical loads.
A high electrical load occurs when several of the
following loads are on: headlamps, high beams, fog
lamps, rear window defogger, climate control fan at
high speed, heated seats, engine cooling fans, trailer
loads, and loads plugged into accessory power outlets.
Battery Run-Down Protection
This feature shuts off the dome lamp if it is left on for
more than 20 minutes when the ignition is in LOCK. This
will help prevent your battery from running down.
3-20

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 5-8. The
diagnostic system can determine if the fuel cap hasbeen 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.
Have you recently changed brands of fuel?
If so, be sure to fuel your vehicle with quality fuel. See
Gasoline Octane on page 5-5. Poor fuel quality causes
the engine not to run as efficiently as designed. You
might notice this as stalling after start-up, stalling when
you put the vehicle into gear, misring, hesitation on
acceleration, or stumbling on acceleration — these
conditions might go away once the engine is warmed up.
This will be detected by the system and cause the light to
turn on.
If you experience one or more of these conditions,
change the fuel brand you use. It will require at least
one full tank of the proper fuel to turn the light off.
If none of the above steps have made the light turn off,
your dealer/retailer can check the vehicle. Your
dealer/retailer has the proper test equipment and
diagnostic tools to x any mechanical or electrical
problems that might have developed.
3-37