HUMMER H3 2007 Owners Manual

Tire Size
The following examples show the different parts of
a tire size.
(A) Passenger (P-Metric) Tire:The United
States version of a metric tire sizing system.
The letter P as the rst character in the tire size
means a passenger vehicle tire engineered
to standards set by the U.S. Tire and Rim
Association.(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.
Passenger (P-Metric) Tire
Light Truck (LT-Metric) Tire
371

(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.
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/
transaxle, 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. SeeInation - Tire Pressure
on page 375.
Curb Weight:This means 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. See
Loading Your Vehicle on page 289.
372

GAWR FRT:Gross Axle Weight Rating for the
front axle. SeeLoading Your Vehicle on page 289.
GAWR RR:Gross Axle Weight Rating for the
rear axle. SeeLoading Your Vehicle on page 289.
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 may 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 289.
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.
373

Recommended Ination Pressure:Vehicle
manufacturer’s recommended tire ination
pressure as shown on the tire placard. See
Ination - Tire Pressure on page 375andLoading
Your Vehicle on page 289.
Radial Ply Tire:A pneumatic tire in which the
ply cords that extend to the beads are laid at
90 degrees to the centerline of the tread.
Rim:A metal support for a tire and upon which
the tire beads are seated.
Sidewall:The portion of a tire between the tread
and the bead.
Speed Rating:An alphanumeric code assigned
to a tire indicating the maximum speed at
which a tire can operate.
Traction:The friction between the tire and the
road surface. The amount of grip provided.
Tread:The portion of a tire that comes into
contact with the road.
Treadwear Indicators:Narrow bands, sometimes
called wear bars, that show across the tread of a
tire when only 1/16 inch (1.6 mm) of tread remains.
SeeWhen It Is Time for New Tires on page 383.UTQGS (Uniform Tire Quality Grading
Standards):A tire information system that
provides consumers with ratings for a tire’s
traction, temperature, and treadwear. Ratings
are determined by tire manufacturers using
government testing procedures. The ratings are
molded into the sidewall of the tire. SeeUniform
Tire Quality Grading on page 386.
Vehicle Capacity Weight:The number of
designated seating positions multiplied by 150 lbs
(68 kg) plus the rated cargo load. SeeLoading
Your Vehicle on page 289.
Vehicle Maximum Load on the Tire:Load on
an individual tire due to curb weight, accessory
weight, occupant weight, and cargo weight.
Vehicle Placard:A label permanently attached to
a vehicle showing the vehicle’s capacity weight
and the original equipment tire size and
recommended ination pressure. See “Tire and
Loading Information Label” underLoading
Your Vehicle on page 289.
374

Ination - Tire Pressure
Tires need the correct amount of air pressure to
operate effectively.
Notice:Do not let anyone tell you that
under-ination or over-ination is all right.
It is not. If your tires do not have enough air
(under-ination), you can get the following:
Too much exing
Too much heat
Tire overloading
Premature or irregular wear
Poor handling
Reduced fuel economy
If your tires have too much air (over-ination),
you can get the following:
Unusual wear
Poor handling
Rough ride
Needless damage from road hazardsA Tire and Loading Information label is attached to
the vehicle’s center pillar (B-pillar), below the
driver’s door latch. This label shows your vehicle’s
original equipment tires and the correct ination
pressures for your tires when they are cold.
The recommended cold tire ination pressure,
shown on the label, is the minimum amount of air
pressure needed to support your vehicle’s
maximum load carrying capacity.
For additional information regarding how much
weight your vehicle can carry, and an example of
the Tire and Loading Information label, see
Loading Your Vehicle on page 289. How you load
your vehicle affects vehicle handling and ride
comfort, never load your vehicle with more weight
than it was designed to carry.
When to Check
Check your tires once a month or more. Also
check the tire pressure of the spare tire. If
you have a compact spare tire, it should be at
60 psi (420 kPa). SeeSpare Tire on page 405for
additional information.
375

How to Check
Use a good quality pocket-type gage to check tire
pressure. You cannot tell if your tires are
properly inated simply by looking at them. Radial
tires may look properly inated even when they
are underinated. Check the tire’s ination
pressure when the tires are cold. Cold means your
vehicle has been sitting for at least three hours
or driven no more than 1 mile (1.6 km).
Remove the valve cap from the tire valve stem.
Press the tire gage rmly onto the valve to
get a pressure measurement. If the cold tire
ination pressure matches the recommended
pressure on the Tire and Loading Information
label, no further adjustment is necessary. If the
ination pressure is low, add air until you reach the
recommended amount.
If you overll the tire, release air by pushing on
the metal stem in the center of the tire valve.
Recheck the tire pressure with the tire gage.
Be sure to put the valve caps back on the valve
stems. They help prevent leaks by keeping out dirt
and moisture.
Tire Pressure Monitor System
Your vehicle has a Tire Pressure Monitor System
(TPMS). This system uses radio and sensor
technology to check tire pressure levels. TPMS
sensors are mounted onto each tire and wheel
assembly on your vehicle, including the spare tire.
The TPMS sensors monitor the air pressure in
your vehicle’s tires and transmit the tire pressure
readings to a receiver located in the vehicle.
When a low tire pressure condition is detected,
the TPMS will illuminate the low tire pressure
warning light located in the instrument panel
cluster, and at the same time display the LOW
TIRE warning message on the Driver Information
Center (DIC). The low tire pressure warning
light and the LOW TIRE warning message appear
at each ignition cycle until the tires are inated
to the correct ination pressure.
376

For additional information and details about the
DIC operation and displays seeDIC Controls and
Displays on page 192andDIC Warnings and
Messages on page 196.
You may notice, during cooler weather conditions,
that the low tire pressure warning light and the
DIC LOW TIRE message may come on when the
vehicle is rst started, and then turn off as you
start to drive. This may be an early indicator that
the air pressure in the tire(s) is getting low
and needs to be inated to the proper pressure.
Each tire, including the spare (if provided), should
be checked monthly when cold and inated to
the ination pressure recommended by the vehicle
manufacturer on the vehicle placard or tire
ination pressure label. (If your vehicle has tires of
a different size than the size indicated on the
vehicle placard or tire ination pressure label, you
should determine the proper tire ination
pressure for those tires.)As an added safety
feature, your vehicle
has been equipped with
a tire pressure
monitoring system
(TPMS) that illuminates
a low tire pressure
telltale when one
or more of your tires is
signicantly
under-inated.
Accordingly, when the low tire pressure telltale
illuminates, you should stop and check your tires
as soon as possible, and inate them to the
proper pressure. Driving on a signicantly
under-inated tire causes the tire to overheat and
can lead to tire failure. Under-ination also
reduces fuel efficiency and tire tread life, and may
affect the vehicle’s handling and stopping ability.
Please note that the TPMS is not a substitute for
proper tire maintenance, and it is the driver’s
responsibility to maintain correct tire pressure, even
if under-ination has not reached the level to trigger
illumination of the TPMS low tire pressure telltale.
377

Your vehicle has also been equipped with a TPMS
malfunction indicator to indicate when the
system is not operating properly. The TPMS
malfunction indicator is combined with the low tire
pressure telltale. When the system detects a
malfunction, the telltale will ash for approximately
one minute and then remain continuously
illuminated. This sequence will continue upon
subsequent vehicle start-ups as long as the
malfunction exists.
When the malfunction indicator is illuminated, the
system may not be able to detect or signal low
tire pressure as intended. TPMS malfunctions may
occur for a variety of reasons, including the
installation of replacement or alternate tires or
wheels on the vehicle that prevent the TPMS from
functioning properly. Always check the TPMS
malfunction telltale after replacing one or more
tires or wheels on your vehicle to ensure that the
replacement or alternate tires and wheels allow
the TPMS to continue to function properly.A Tire and Loading Information label, attached to
your vehicle, shows the size of your vehicle’s
original equipment tires and the correct ination
pressure for your vehicle’s tires when they
are cold. SeeLoading Your Vehicle on page 289,
for an example of the Tire and Loading
Information label and its location on your vehicle.
Also seeInation - Tire Pressure on page 375
for additional information.
Your vehicle’s TPMS can warn you about a low
tire pressure condition but it does not replace
normal tire maintenance. SeeTire Inspection and
Rotation on page 381,When It Is Time for
New Tires on page 383, andTires on page 367.
Notice:Do not use a tire sealant if your
vehicle has Tire Pressure Monitors. The liquid
sealant can damage the tire pressure monitor
sensors.
378

TPMS Sensor Identication Codes
Each TPMS sensor has a unique identication
code. Any time you replace one or more of
the TPMS sensors, install the spare tire onto your
vehicle, or rotate your vehicle’s tires, 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’s side front tire, passenger’s side
front tire, passenger’s side rear tire, and driver’s
side rear tire using a TPMS diagnostic tool.
See your dealer for service.
The TPMS sensors may 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.
You will have one minute to match the rst
tire/wheel position, and ve minutes overall, to
match all four tire/wheel positions.If it takes longer than one minute, 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 will need to
start over.
The TPMS sensor matching procedure is
outlined below:
1. Set the parking brake.
2. Turn the ignition switch to ON with the
engine off.
3. Turn the exterior lamp switch from AUTO to
ON four times within three seconds. A double
horn chirp will sound and the TPMS low
tire warning light will begin to ash. The
double horn chirp and ashing TPMS warning
light indicates the TPMS matching process
has started. The TPMS warning light should
continue ashing throughout the matching
procedure. The SERV TPM message will be
displayed on the Driver Information
Center (DIC).
4. Start with the driver’s side front tire.
379

5. Remove the valve cap from the valve cap
stem. Activate the TPMS sensor by
increasing or decreasing the tire’s air pressure
for 10 seconds, then stop and listen for a
single horn chirp. The single horn chirp should
sound within 15 seconds, conrming that
the sensor identication code has been
matched to this tire and wheel position. If you
do not hear the conrming single horn
chirp, you will need to start over with step
number one. To let 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.
6. Proceed to the passenger’s side front tire,
and repeat the procedure in Step 5.
7. Proceed to the passenger’s side rear tire,
and repeat the procedure in Step 5.8. Proceed to the driver’s side rear tire, and
repeat the procedure in Step 5.
9. After hearing the conrming horn chirp
for the left rear tire, check to see if
the TPMS warning light is still ashing.
If it is, turn the ignition switch to LOCK.
If the TPMS warning light is not ashing,
the ve minute time limit has passed and
you will need to start the process
over beginning with Step 1.
10. Set all four tires to the recommended air
pressure level as indicated on the Tire
and Loading Information label.
11. Put the valve caps back on the valve stems.
380