2008 HUMMER H2 height

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

Brake Wear
Your vehicle has disc brakes. Disc brake pads have
built-in wear indicators that make a high-pitched warning
sound when the brake pads are worn and new pads
are needed. The sound can come and go or be heard all
the time your vehicle is moving, except when you are
pushing on the brake pedal rmly.
{CAUTION:
The brake wear warning sound means that
soon the brakes will not work well. That could
lead to an accident. When you hear the brake
wear warning sound, have your vehicle
serviced.
Notice:Continuing to drive with worn-out brake
pads could result in costly brake repair.Some driving conditions or climates can cause a brake
squeal when the brakes are rst applied or lightly
applied. This does not mean something is wrong with
the brakes.
Properly torqued wheel nuts are necessary to help
prevent brake pulsation. When tires are rotated, inspect
brake pads for wear and evenly tighten wheel nuts in
the proper sequence to torque specications in
Capacities and Specifications on page 5-117.
Brake linings should always be replaced as complete
axle sets.Brake Pedal Travel
See your dealer/retailer if the brake pedal does not
return to normal height, or if there is a rapid increase in
pedal travel. This could be a sign that brake service
might be required.
Brake Adjustment
Every time you make a brake stop, the disc brakes
adjust for wear.
5-38

Tire Sidewall Labeling
Useful information about a tire is molded into the
sidewall. The following illustrations are examples
of a typical LT-Metric tire sidewall.
(A) Tire Size
:The tire size code is a combination
of letters and numbers used to dene a particular
tire’s width, height, aspect ratio, construction
type, and service description. See the “Tire Size”
illustration later in this section for more detail.(B) TPC Spec (Tire Performance Criteria
Specication)
:Original equipment tires designed
to GM’s specic tire performance criteria have
a TPC specication code molded onto the sidewall.
GM’s TPC specications meet or exceed all
federal safety guidelines.
(C) Dual Tire Maximum Load
:Maximum load
that can be carried and the maximum pressure
needed to support that load when used in a dual
conguration. For information on recommended
tire pressure seeInflation - Tire Pressure on
page 5-61andLoading Your Vehicle on page 4-44.
(D) DOT (Department of Transportation)
:The Department of Transportation (DOT) code
indicates that the tire is in compliance with the
U.S. Department of Transportation Motor Vehicle
Safety Standards.
(E) Tire Identication Number (TIN)
:The letters
and numbers following DOT code are the Tire
Identication Number (TIN). The TIN shows
the manufacturer and plant code, tire size, and
date the tire was manufactured. The TIN is molded
onto both sides of the tire, although only one
side may have the date of manufacture.
Light Truck (LT-Metric) Tire
5-56

(F) Tire Ply Material:The type of cord and number
of plies in the sidewall and under the tread.
(G) Single Tire Maximum Load
:Maximum load
that can be carried and the maximum pressure
needed to support that load when used as a
single. For information on recommended
tire pressure seeInflation - Tire Pressure on
page 5-61andLoading Your Vehicle on page 4-44.
Tire Size
The following examples show the different parts of
a tire size.
(A) Light Truck (LT-Metric) Tire
:The United
States version of a metric tire sizing system.
The letters LT as the rst two characters in the tire
size means a light truck tire engineered to
standards set by the U.S. Tire and Rim Association.(B) Tire Width
:The three-digit number indicates
the tire section width in millimeters from sidewall
to sidewall.
(C) Aspect Ratio
:A two-digit number that
indicates the tire height-to-width measurements.
For example, if the tire size aspect ratio is 75,
as shown in item C of the light truck (LT-Metric)
tire illustration, it would mean that the tire’s
sidewall is 75 percent as high as it is wide.
(D) Construction Code
:A letter code is used to
indicate the type of ply construction in the tire.
The letter R means radial ply construction;
the letter D means diagonal or bias ply
construction; and the letter B means belted-bias
ply construction.
(E) Rim Diameter
:Diameter of the wheel in
inches.
(F) Service Description
:The service description
indicates the load range and speed rating of a
tire. The load index can range from 1 to 279.
Speed ratings range from A to Z.
Light Truck (LT-Metric) Tire
5-57

Tire Terminology and Denitions
Air Pressure:The amount of air inside the
tire pressing outward on each square inch of the
tire. Air pressure is expressed in pounds per
square inch (psi) or kilopascal (kPa).
Accessory Weight
:This means the combined
weight of optional accessories. Some examples of
optional accessories are, automatic transmission,
power steering, power brakes, power windows,
power seats, and air conditioning.
Aspect Ratio
:The relationship of a tire’s height
to its width.
Belt
:A rubber coated layer of cords that is located
between the plies and the tread. Cords may be
made from steel or other reinforcing materials.
Bead
:The tire bead contains steel wires wrapped
by steel cords that hold the tire onto the rim.
Bias Ply Tire
:A pneumatic tire in which the plies
are laid at alternate angles less than 90 degrees
to the centerline of the tread.Cold Tire Pressure
:The amount of air pressure
in a tire, measured in pounds per square inch
(psi) or kilopascals (kPa) before a tire has built up
heat from driving. SeeInflation - Tire Pressure
on page 5-61.
Curb Weight
:The weight of a motor vehicle with
standard and optional equipment including the
maximum capacity of fuel, oil, and coolant,
but without passengers and cargo.
DOT Markings
:A code molded into the sidewall
of a tire signifying that the tire is in compliance
with the U.S. Department of Transportation (DOT)
motor vehicle safety standards. The DOT code
includes the Tire Identication Number (TIN),
an alphanumeric designator which can also identify
the tire manufacturer, production plant, brand,
and date of production.
GVWR
:Gross Vehicle Weight Rating.
SeeLoading Your Vehicle on page 4-44.
GAWR FRT
:Gross Axle Weight Rating for the
front axle. SeeLoading Your Vehicle on
page 4-44.
5-58

Notice:The wrong wheel can also cause problems
with bearing life, brake cooling, speedometer or
odometer calibration, headlamp aim, bumper height,
vehicle ground clearance, and tire or tire chain
clearance to the body and chassis.
SeeChanging a Flat Tire on page 5-78for more
information.
Used Replacement Wheels
{CAUTION:
Putting a used wheel on your vehicle is
dangerous. You cannot know how it has been
used or how far it has been driven. It could fail
suddenly and cause a crash. If you have to
replace a wheel, use a new GM original
equipment wheel.
Tire Chains
Notice:Use tire chains only where legal and only
when you must. Use only SAE Class U-type
chains that are the proper size for your tires. Install
them on the rear axle tires and tighten them as
tightly as possible with the ends securely fastened.
Drive slowly and follow the chain manufacturer’s
instructions. If you can hear the chains contacting
your vehicle, stop and retighten them. If the contact
continues, slow down until it stops. Driving too
fast or spinning the wheels with chains on will
damage your vehicle.
5-75

R
Radio Frequency Identication (RFID), Privacy....7-17
Radios..........................................................3-72
Radio(s)........................................................3-75
Radios
Navigation/Radio System,
see Navigation Manual............................3-104
Rear Seat Audio........................................3-114
Reception.................................................3-117
Setting the Clock.........................................3-73
Theft-Deterrent..........................................3-116
Reading Lamps..............................................3-19
Rear Air Conditioning and Heating System
and Electronic Climate Controls.....................3-29
Rear Axle......................................................5-45
Locking........................................................ 4-6
Rear Door Security Locks................................2-12
Rear Heated Seats........................................... 1-8
Rear Seat Armrest..........................................2-65
Rear Seat Audio (RSA)..................................3-114
Rear Seat Entertainment System.....................3-105
Rear Vision Camera........................................2-50
Rear Windshield Washer/Wiper.........................3-11
Rearview Mirror, Automatic Dimming with
Compass and Temperature Display................2-45
Reclining Seatbacks, Power............................... 1-5Recommended Fluids and Lubricants.................6-12
Recovery Loops..............................................4-40
Recreational Vehicle Towing.............................4-51
Remote Keyless Entry (RKE) System.................. 2-4
Remote Keyless Entry (RKE) System, Operation . . . 2-5
Remote Vehicle Start........................................ 2-8
Removing the Flat Tire and Installing
the Spare Tire.............................................5-88
Removing the Spare Tire and Tools...........5-80, 5-84
Replacement Bulbs.........................................5-53
Replacement Parts, Maintenance......................6-14
Reporting Safety Defects
Canadian Government..................................7-14
General Motors...........................................7-14
United States Government............................7-14
Restraint System Check
Checking the Restraint Systems....................1-76
Replacing Restraint System Parts
After a Crash..........................................1-77
Retained Accessory Power (RAP)......................2-29
Ride Height, Selectable Extended Rear Ride......4-53
Roadside
Assistance Program....................................... 7-6
Rocking Your Vehicle to Get it Out....................4-40
Routing, Engine Drive Belt...............................6-15
Running the Engine While Parked.....................2-44
10

S
Safety Belt
Reminder Light............................................3-33
Safety Belts
Care of....................................................5-103
How to Wear Safety Belts Properly................1-22
Lap-Shoulder Belt........................................1-30
Safety Belt Extender....................................1-35
Safety Belt Use During Pregnancy.................1-35
Safety Belts Are for Everyone.......................1-16
Safety Warnings and Symbols.............................. iii
Scheduled Maintenance..................................... 6-4
Seats
Head Restraints............................................ 1-7
Heated Seats............................................... 1-4
Heated Seats - Rear..................................... 1-8
Memory, Mirrors............................................ 1-4
Power Lumbar.............................................. 1-3
Power Reclining Seatbacks............................. 1-5
Power Seats................................................. 1-2
Split Folding Rear Seat.................................. 1-8
Third Row Seat...........................................1-10
Securing a Child Restraint
Rear Seat Position......................................1-57
Right Front Seat Position..............................1-60
Security Light.................................................3-46
Selectable Extended Rear Ride Height...............4-53Service........................................................... 5-3
Accessories and Modications......................... 5-3
Adding Equipment to the Outside of
Your Vehicle.............................................. 5-4
California Pershlorate Materials Requirements.... 5-4
California Proposition 65 Warning.................... 5-3
Doing Your Own Work................................... 5-4
Engine Soon Light.......................................3-42
Publications Ordering Information...................7-15
Service, Scheduling Appointments....................... 7-8
Servicing Your Airbag-Equipped Vehicle..............1-75
Sheet Metal Damage.....................................5-106
Shifting Into Park (P).......................................2-41
Shifting Out of Park (P)...................................2-42
Side Steps.....................................................4-32
Signals, Turn and Lane-Change.......................... 3-8
Spare Tire.....................................................5-99
Carrier, Tailgate...........................................2-16
Installing....................................................5-88
Removing...........................................5-80, 5-84
Storing...............................................5-94, 5-96
Specications, Capacities...............................5-117
Speedometer..................................................3-33
Split Folding Rear Seat..................................... 1-8
StabiliTrak
®System.......................................... 4-7
StabiliTrak®Indicator Light................................3-40
Start Vehicle, Remote....................................... 2-8
Starting the Engine.........................................2-30
11