2008 HUMMER H2 ECO mode

Electronically Controlled Air
Suspension System
The electronically controlled air suspension, if equipped,
keeps the rear of your vehicle level under all load
conditions. The system maintains the vehicle at the
currently selected ride height. There are two ride
heights: Normal Ride Height and Extended Ride Height.
The Extended Ride Height feature is only available if
the vehicle speed is below 40 mph (64 km/h). If the
vehicle is at Extended Ride Height and the speed
exceeds 40 mph (64 km/h), the system will automatically
return the vehicle to Normal Ride Height. The activation
and deactivation of the Extended Ride Height feature
is controlled by a switch on the instrument panel.
The system includes a compressor, two height sensors
and two air springs supporting the vehicle.
The system is activated when the engine is started and
deactivated when the ignition is returned to OFF.
The engine must be running for the rear of the vehicle
to be raised and the doors must be closed to enable
a transition between Normal Ride Height and Extended
Ride Height.
You may hear the compressor running whilst the system
is active and you may also hear the release of air
similar to a hissing sound. This is normal.Load leveling will not function normally with the
inater hose attached to the inator outlet. Remove
the hose from the outlet when it is not in use.
SeeAccessory Inflator on page 5-75.
Overload and Overheat Protection
Overload protection is designed to protect the air
suspension system and is an indication to the driver that
the vehicle is overloaded.
If the rear suspension remains at a low height, the rear
axle load has exceeded GAWR (Gross Axle Weight
Rating). When the overload protection mode is activated,
the compressor operates for about 30 seconds to
one minute without raising the vehicle depending on the
amount of overload. This will continue each time the
ignition is turned on until the rear axle load is reduced
below GAWR. The system may reactivate without
cycling the ignition if some of the excess load is
removed.
If the total rear GAWR (Gross Axle Weight Rating) is
reached, the suspension may be slightly less than level.
This is normal and does not mean there is a problem
with the air suspension.
4-54

Tow/Haul mode is most effective when the vehicle and
trailer combined weight is at least 75 percent of the
vehicle’s Gross Combination Weight Rating (GCWR).
See “Weight of the Trailer” later in this section.
Press the button on the
instrument panel to the
right of the steering wheel
to enable the tow/haul
mode.
A light on the instrument
panel will illuminate to
indicate that tow/haul
mode has been selected.Press the button again to turn off Tow/Haul mode.
The indicator light on the instrument panel will turn off.
The vehicle will automatically turn off Tow/Haul mode
every time it is started.
Driving with Tow/Haul mode activated without a heavy
load or with no trailer will cause reduced fuel economy
and unpleasant engine and transmission driving
characteristics, but will not cause damage.
Grade Braking
Transmission Grade Braking works in Tow/Haul mode
to automatically downshift the transmission when
the driver is braking. The purpose is to aid in braking or
maintaining vehicle speeds on down-grades by
shifting to a lower gear to utilize engine braking.
4-57

GAWR RR:Gross Axle Weight Rating for the rear
axle. SeeLoading Your Vehicle on page 4-44.
Intended Outboard Sidewall
:The side of
an asymmetrical tire, that must always face
outward when mounted on a vehicle.
Kilopascal (kPa)
:The metric unit for air pressure.
Light Truck (LT-Metric) Tire
:A tire used on
light duty trucks and some multipurpose passenger
vehicles.
Load Index
:An assigned number ranging from
1 to 279 that corresponds to the load carrying
capacity of a tire.
Maximum Ination Pressure
:The maximum air
pressure to which a cold tire can be inated.
The maximum air pressure is molded onto the
sidewall.
Maximum Load Rating
:The load rating for a tire
at the maximum permissible ination pressure
for that tire.
Maximum Loaded Vehicle Weight
:The sum of
curb weight, accessory weight, vehicle capacity
weight, and production options weight.Normal Occupant Weight
:The number of
occupants a vehicle is designed to seat multiplied
by 150 lbs (68 kg). SeeLoading Your Vehicle
on page 4-44.
Occupant Distribution
:Designated seating
positions.
Outward Facing Sidewall
:The side of an
asymmetrical tire that has a particular side that
faces outward when mounted on a vehicle.
The side of the tire that contains a whitewall, bears
white lettering, or bears manufacturer, brand,
and/or model name molding that is higher
or deeper than the same moldings on the other
sidewall of the tire.
Passenger (P-Metric) Tire
:A tire used on
passenger cars and some light duty trucks and
multipurpose vehicles.
Recommended Ination Pressure
:Vehicle
manufacturer’s recommended tire ination
pressure as shown on the tire placard.
SeeInflation - Tire Pressure on page 5-61
andLoading Your Vehicle on page 4-44.
5-59

TPMS Sensor Matching Process
Each TPMS sensor has a unique identication code.
Any time you rotate your vehicle’s tires or replace one or
more of the TPMS sensors, the identication codes
will need to be matched to the new tire/wheel position.
The sensors are matched to the tire/wheel positions
in the following order: driver side front tire, passenger
side front tire, passenger side rear tire, and driver
side rear tire using a TPMS diagnostic tool. See your
dealer/retailer for service.
The TPMS sensors can also be matched to each
tire/wheel position by increasing or decreasing the tire’s
air pressure. If increasing the tire’s air pressure, do
not exceed the maximum ination pressure indicated on
the tire’s sidewall.
To decrease air-pressure out of a tire you can use the
pointed end of the valve cap, a pencil-style air pressure
gage, or a key.You have two minutes to match the rst tire/wheel
position, and ve minutes overall to match all four
tire/wheel positions. If it takes longer than two minutes,
to match the rst tire and wheel, or more than
ve minutes to match all four tire and wheel positions
the matching process stops and you need to start over.
The TPMS sensor matching process is outlined below:
1. Set the parking brake.
2. Turn the ignition switch to ON/RUN with the
engine off.
3. Press the Remote Keyless Entry (RKE) transmitter’s
LOCK and UNLOCK buttons at the same time for
approximately ve seconds. The horn sounds twice
to signal the receiver is in relearn mode and
TIRE LEARNING ACTIVE message displays on
the DIC screen.
4. Start with the driver side front tire.
5. Remove the valve cap from the valve cap stem.
Activate the TPMS sensor by increasing or
decreasing the tire’s air pressure for ve seconds,
or until a horn chirp sounds. The horn chirp,
which may take up to 30 seconds to sound,
conrms that the sensor identication code has
been matched to this tire and wheel position.
5-66

Capacities and Specications
The following approximate capacities are given in English and metric. Please refer toRecommended Fluids and
Lubricants on page 6-12for more information.
Capacities and Specications
ApplicationCapacities
English Metric
Air Conditioning Refrigerant R134aFor the air conditioning system refrigerant charge
amount, see the refrigerant caution label located
under the hood. See your dealer/retailer for more
information.
Cooling System
1
SUV Model 16.7 qt 15.8 L
SUT Model 15.4 qt 14.6 L
Engine Oil with Filter
26.0 qt 5.7 L
Fuel Tank 32.0 gal 121.0 L
Transmission Fluid (Pan Removal and Filter Replacement) 6.0 qt 5.7 L
5-117

E
EDR .............................................................7-16
Electrical System
Add-On Equipment.....................................5-110
Center Instrument Panel Fuse Block.............5-112
Fuses and Circuit Breakers.........................5-110
Instrument Panel Fuse Block.......................5-111
Power Windows and Other Power Options....5-110
Underhood Fuse Block...............................5-113
Windshield Wiper Fuses.............................5-110
Electronically Controlled Air Suspension System . . . 4-54
Engine
Air Cleaner/Filter.........................................5-18
Check and Service Engine Soon Light............3-42
Coolant......................................................5-24
Coolant Heater............................................2-31
Coolant Temperature Gage...........................3-40
Drive Belt Routing.......................................6-15
Engine Compartment Overview......................5-12
Exhaust.....................................................2-43
Fan Noise..................................................5-33
Oil .............................................................5-13
Oil Life System...........................................5-16
Overheated Protection Operating Mode...........5-28
Overheating................................................5-27
Running While Parked..................................2-44
Starting......................................................2-30Entry/Exit Lighting...........................................3-19
Event Data Recorders.....................................7-16
Extender, Safety Belt.......................................1-35
Exterior Lamps...............................................3-15
F
Filter
Engine Air Cleaner......................................5-18
Finish Damage.............................................5-107
First Aid Kit....................................................4-42
Fixed Mast Antenna.......................................3-118
Flashers, Hazard Warning.................................. 3-6
Flash-to-Pass................................................... 3-9
Flat Tire........................................................5-78
Flat Tire, Changing.........................................5-78
Flat Tire, Storing.....................................5-94, 5-96
Fluid.............................................................5-21
Power Steering...........................................5-34
Windshield Washer......................................5-35
Folding Rear Seat............................................ 1-8
Four-Wheel Drive............................................5-46
Four-Wheel Drive, Full-Time.............................2-36
Front Axle......................................................5-47
Front Mounted Receiver...................................4-43
5

O
Odometer......................................................3-33
Odometer, Trip...............................................3-33
Off-Road Driving.............................................4-13
Off-Road Recovery..........................................4-11
Oil
Engine.......................................................5-13
Pressure Gage............................................3-45
Pressure Light.............................................3-46
Oil, Engine Oil Life System..............................5-16
Older Children, Restraints................................1-36
Online Owner Center........................................ 7-4
OnStar, Privacy..............................................7-17
OnStar
®System, see OnStar®Manual...............2-53
Operation, Universal Home Remote System........2-57
Other Warning Devices...................................... 3-6
Outlet Adjustment............................................3-29
Outlets
Accessory Power.........................................3-20
Outside
Automatic Dimming Mirror.............................2-49
Convex Mirror.............................................2-49
Heated Mirrors............................................2-49
Power Foldaway Mirrors...............................2-48
Overheated Engine Protection Operating Mode....5-28
Owner Checks and Services.............................. 6-8
Owners, Canadian............................................... ii
P
Paint, Damage..............................................5-107
Park Aid........................................................2-50
Park Brake....................................................2-40
Park (P)
Shifting Into................................................2-41
Shifting Out of............................................2-42
Parking
Over Things That Burn.................................2-43
Passing.........................................................4-12
PASS-Key
®III+..............................................2-26
PASS-Key®III+ Operation................................2-26
Perchlorate Materials Requirements, California...... 5-4
Power
Door Locks.................................................2-11
Electrical System.......................................5-110
Lumbar Controls........................................... 1-3
Reclining Seatbacks...................................... 1-5
Retained Accessory (RAP)............................2-29
Seat............................................................ 1-2
Steering Fluid.............................................5-34
Windows....................................................2-20
Power Winch Platform.....................................4-43
Privacy..........................................................7-16
Event Data Recorders..................................7-16
Navigation System.......................................7-17
OnStar.......................................................7-17
Radio Frequency Identication.......................7-17
Programmable Automatic Door Locks.................2-11
9