HUMMER H3 2008 Owners Manual

Up-Shift Light
This light will show you
when to shift to the next
higher gear for best
fuel economy.
When this light comes on, you can shift to the next
higher gear if weather, road and traffic conditions permit.
For the best fuel economy, accelerate slowly and shift
when the light comes on.
While you accelerate, it is normal for the light to go
on and off if you quickly change the position of
the accelerator. Ignore the shift light when you
downshift.
If your vehicle has four-wheel drive and has a manual
transmission, disregard the shift light when the transfer
case is in four-wheel low.
For more information, seeUp-Shift Light on page 3-32.
Shift Speeds
{CAUTION:
If you skip a gear when you downshift, you
could lose control of your vehicle. You could
injure yourself or others. Do not shift down
more than one gear at a time when you
downshift.
Full-Time Four-Wheel Drive
Full-Time Four-Wheel Drive sends your 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.
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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.
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Indicator lights in the buttons show which mode you
are in. The indicator lights will come on briey when
you turn on the ignition the mode the vehicle is in
will stay on. If the lights do not come on, you should
take your vehicle to your dealer for service. An indicator
light will ash while shifting the transfer case. It will
remain lit when the shift is complete. If for some reason
the transfer case cannot make a requested shift,
it will return to the last chosen setting.
If the SERV 4WD message on the Driver Information
Center (DIC) stays on, you should take your vehicle to
your dealer for service. See Service 4WD message
underDIC Warnings and Messages on page 3-43.
Shifting between Four-Wheel High
and Four-Wheel-High Lock
With the vehicle traveling less than 45 mph
(72 km/h), press and release the Four-Wheel High
or Four-Wheel-High Lock button. The indicator light
will ash while shifting. It will remain lit when the
shift is complete.
It may be necessary to drive backwards while turning
for a distance of 25 feet (7.5 m) to get the lock
feature to disengage.
Shifting into Four-Wheel Low Lock
Notice:Shifting the transmission into gear before
the indicator light stops ashing could cause
damage to the transfer case. Always wait until the
indicator light stops ashing before putting the
transmission back in gear.
To shift into Four-Wheel-Low Lock, the ignition must be in
ON and the vehicle must be stopped or moving less than
3 mph (5 km/h) with the transmission in NEUTRAL (N).
The preferred method for shifting into Four-Wheel Low is
to have your vehicle moving 1 to 2 mph (1.6 to 3.2 km/h).
Press and release the Four-Wheel-Low Lock button.
If your vehicle has a manual transmission, the clutch
pedal must be pressed to the oor while you press the
Four-Wheel-Low Lock button, or the shift will not be
completed. You must wait for the Four-Wheel-Low Lock
indicator light to stop ashing and remain lit before
shifting your transmission in gear.
It is normal for your vehicle to have engagement noise
and bump when shifting between Four-Wheel Low
and Four-Wheel High ranges or from NEUTRAL with
the engine running.
If the Four-Wheel-Low Lock button is pressed when
your vehicle is in gear and/or moving too fast, the
Four-Wheel-Low Lock indicator light will ash for
15 seconds and not complete the shift unless your
vehicle is moving less than 3 mph (5 km/h) and
the transmission is in NEUTRAL (N). After 15 seconds
the transfer case will return to the last chosen setting.
2-29

Shifting Out of Four-Wheel-Low Lock
Notice:Shifting the transmission into gear before
the indicator light stops ashing could cause
damage to the transfer case. Always wait until the
indicator light stops ashing before putting the
transmission back in gear.
To shift out of Four-Wheel-Low Lock, your vehicle must
be stopped or moving less than 3 mph (5 km/h) with the
transmission in NEUTRAL (N) and the ignition in ON. The
preferred method for shifting out of Four-Wheel-Low
Lock is to have your vehicle moving 1 to 2 mph
(1.6 to 3.2 km/h). Press and release the Four-Wheel High
or Four-Wheel-High Lock button. If your vehicle has a
manual transmission, the clutch pedal must be pressed
to the oor while you press the Four-Wheel High or
Four-Wheel-High Lock button, or the shift will not be
completed. You must wait for the Four-Wheel High or
Four-Wheel-High Lock indicator light to stop ashing and
remain lit before shifting your transmission into gear.It is normal for your vehicle to have engagement noise
and bump when shifting between Four-Wheel Low
and Four-Wheel High ranges or from NEUTRAL with
the engine running.
If the Four-Wheel High or Four-Wheel-High Lock button
is pressed when your vehicle is in gear and/or moving
too fast, the Four-Wheel High or Four-Wheel-High Lock
indicator light will ash for 15 seconds but will not
complete the shift unless your vehicle is moving less than
3 mph (5 km/h) and the transmission is in NEUTRAL (N).
Shifting Into NEUTRAL
To shift the transfer case to NEUTRAL, do the following:
1. Set the parking brake.
2. Start the vehicle by turning the ignition to START.
3. Put the transmission in NEUTRAL (N). If your
vehicle has a manual transmission, press and
hold the clutch pedal down while you perform
Steps 5 through 9.
4. Shift the transfer case to Four-Wheel High.
2-30

{CAUTION:
Shifting an all-wheel-drive vehicle’s transfer
case into NEUTRAL can cause your vehicle to
roll even if the automatic transmission is in
PARK (P) or the manual transmission is in
any gear. You or others could be injured.
Make sure the parking brake is rmly set
before you shift the transfer case to NEUTRAL.
5. Simultaneously press and hold the Four-Wheel
High and Four-Wheel-Low Lock buttons for
10 seconds. The NEUTRAL light will come on when
the transfer case shift to NEUTRAL is complete.
6. Press and hold the regular brake pedal and Shift
the transmission to REVERSE (R) for one second,
then shift the transmission for one second to
DRIVE (D) for an automatic transmission, or
FIRST (1) for vehicles have a manual transmission
and then let out the clutch. This is to ensure the
transfer case is in NEUTRAL. If not, repeat
this procedure starting at Step 3.
7. Turn the engine off, by turning the key to ACC.8. Place the transmission shift lever in PARK (P) for
an automatic transmission, or FIRST (1) for
vehicles that have a manual transmission.
9. Turn the ignition to LOCK/OFF.Shifting Out of NEUTRAL
To shift out of NEUTRAL:
1. Set the parking brake and apply the regular
brake pedal.
2. Shift the transmission to NEUTRAL (N) for an
automatic transmission, or press the clutch pedal
for vehicles that have a manual transmission.
Then turn the ignition to ON with the engine off.
3. Press the button for the desired transfer case shift
position (Four-Wheel High, Four-Wheel-High Lock
or Four-Wheel-Low Lock).
After the transfer case has shifted out of
NEUTRAL the light will go out.
4. Release the parking brake.
Notice:Shifting the transmission into gear before
the indicator light stops ashing could cause
damage to the transfer case. Always wait until the
indicator light stops ashing before putting the
transmission back in gear.
5. You may start the engine and shift the transmission
to the desired position.
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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

Leaving Your Vehicle With the Engine
Running (Automatic Transmission)
{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 shift lever button. If you can, it means
that the shift lever was not fully locked into PARK (P).
Torque Lock (Automatic Transmission)
If you are parking on a hill and you do not shift your
transmission into PARK (P) properly, the weight of the
vehicle may put too much force on the parking pawl
in the transmission. You may nd it difficult to pull the
shift lever out of PARK (P). This is called “torque
lock.” To prevent torque lock, set the parking brake
and then shift into PARK (P) properly before you leave
the driver’s seat. To nd out how, seeShifting Into
PARK (P) (Automatic Transmission) on page 2-33.
When you are ready to drive, move the shift lever out of
PARK (P) before you release the parking brake.
If torque lock does occur, you may need to have another
vehicle push yours a little uphill to take some of the
pressure from the parking pawl in the transmission,
so you can pull the shift lever out of PARK (P).
2-34

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

Parking Over Things That Burn
{CAUTION:
Things that can burn could touch hot exhaust
parts under your vehicle and ignite. Do not
park over papers, leaves, dry grass, or other
things that can burn.
Engine Exhaust
{CAUTION:
Engine exhaust can kill. It contains the gas
carbon monoxide (CO), which you cannot see or
smell. It can cause unconsciousness and death.
You might have exhaust coming in if:
The exhaust system sounds strange
or different.
Your vehicle gets rusty underneath.
Your vehicle was damaged in a collision.
Your vehicle was damaged when driving
over high points on the road or over
road debris.
Repairs were not done correctly.
Your vehicle or the exhaust system has
been modied improperly.
If you ever suspect exhaust is coming into
your vehicle:
Drive it only with all the windows down
to blow out any CO; and
Have your vehicle xed immediately.
2-36