wheel HUMMER H3 2008 User Guide

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

If you cannot shift out of PARK (P), ease pressure on
the shift lever and push the shift lever all the way
into PARK (P) as you maintain brake application. Then
press the shift lever button and move the shift lever
into another gear. SeeShifting Out of PARK (P)
(Automatic Transmission) on page 2-35
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.
To rock your vehicle back and forth to get out of snow,
ice, or sand without damaging your transmission,
seeIf Your Vehicle is Stuck in Sand, Mud, Ice, or Snow
on page 4-39
NEUTRAL (N):In this position, your engine does not
connect with the wheels. To restart when you are
already moving, use NEUTRAL (N) only.
{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.
2-24

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.
2-27

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

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.
2-31

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

Instrument Panel Overview...............................3-4
Hazard Warning Flashers................................3-6
Other Warning Devices...................................3-6
Horn.............................................................3-6
Tilt Wheel.....................................................3-7
Turn Signal/Multifunction Lever.........................3-7
Turn and Lane-Change Signals........................3-8
Headlamp High/Low-Beam Changer..................3-9
Flash-to-Pass.................................................3-9
Windshield Wipers........................................3-10
Windshield Washer.......................................3-10
Rear Window Wiper/Washer...........................3-11
Cruise Control..............................................3-11
Exterior Lamps.............................................3-15
Headlamps on Reminder................................3-16
Daytime Running Lamps (DRL).......................3-17
Automatic Headlamp System..........................3-17
Off-Road Lamps...........................................3-18
Fog Lamps..................................................3-19
Instrument Panel Brightness...........................3-19
Dome Lamp.................................................3-19
Dome Lamp Override....................................3-20
Exit Lighting.................................................3-20
Reading Lamps............................................3-20Electric Power Management...........................3-20
Battery Run-Down Protection..........................3-20
Accessory Power Outlet(s).............................3-21
Ashtray(s) and Cigarette Lighter......................3-22
Climate Controls............................................3-22
Climate Control System.................................3-22
Outlet Adjustment.........................................3-24
Warning Lights, Gages, and Indicators............3-25
Instrument Panel Cluster................................3-26
Speedometer and Odometer..........................
.3-27
Trip Odometer..............................................3-27
Tachometer.................................................3-27
Safety Belt Reminders...................................3-28
Airbag Readiness Light..................................3-29
Passenger Airbag Status Indicator...................3-30
Charging System Light..................................3-32
Up-Shift Light...............................................3-32
Brake System Warning Light..........................3-33
Antilock Brake System Warning Light...............3-34
Traction Off Light..........................................3-34
StabiliTrak
®Not Ready Light..........................3-34
Engine Coolant Temperature Gage..................3-35
Tire Pressure Light.......................................3-35
Section 3 Instrument Panel
3-1

The main components of your instrument panel are the following:
A. Air Outlets. SeeOutlet Adjustment on page 3-24.
B. Turn Signal/Multifunction Lever. SeeTurn Signal/
Multifunction Lever on page 3-7. Windshield
Washer/Wiper. SeeWindshield Wipers on page 3-10
andWindshield Washer on page 3-10. Cruise
Controls. SeeCruise Control on page 3-11.
C. Horn. SeeHorn on page 3-6.
D. Instrument Panel Cluster. SeeInstrument Panel
Cluster on page 3-26.
E. Hazard Warning Flasher Button. SeeHazard
Warning Flashers on page 3-6.
F. All-Wheel Drive, Passenger Air Bag Status Indicator,
Locking Rear Axle, and Traction Control System/
StabiliTrak
®Buttons. SeeFull-Time Four-Wheel
Drive on page 2-27,Passenger Airbag Status
Indicator on page 3-30,Locking Rear Axle on
page 4-6,Traction Control System (TCS) on
page 4-5andStabiliTrak
®System on page 4-7.
G. Exterior Lamps Control, Dome Override Button,
Instrument Panel Brightness Control, Fog Lamp
Button, and OnStar
®Button. SeeExterior Lamps on
page 3-15,Dome Lamp Override on page 3-20,
Instrument Panel Brightness on page 3-19,
Fog Lamps on page 3-19, andOnStar
®System on
page 2-48.H. Parking Brake Release. SeeParking Brake on
page 2-32.
I. Audio System. SeeAudio System(s) on page 3-48.
J. Climate Control System. SeeClimate Control
System on page 3-22.
K. Rear Washer/Wiper Control. SeeRear Window
Wiper/Washer on page 3-11.
L. Off-Road Lamps Buttons. SeeOff-Road Lamps on
page 3-18.
M. Shift Lever. SeeAutomatic Transmission Operation
on page 2-23orManual Transmission Operation
on page 2-26.
N. Accessory Power Outlets. SeeAccessory Power
Outlet(s) on page 3-21.
O. Glove Box. SeeGlove Box on page 2-56.
3-5