Page 321 of 410

Vehicle Care 10-55
.The TPMS sensor matching
process was started but not
completed or not completed
successfully after rotating the
vehicle's tires. The DIC message
and TPMS malfunction light
should go off once the TPMS
sensor matching process is
performed successfully. See
“TPMS Sensor Matching
Process”later in this section.
.One or more TPMS sensors
are missing or damaged. The
DIC message and the TPMS
malfunction light should go
off when the TPMS sensors
are installed and the sensor
matching process is performed
successfully. See your
dealer/retailer for service.
.Replacement tires or wheels do
not match the vehicle's original
equipment tires or wheels. Tires
and wheels other than those
recommended for the vehicle
could prevent the TPMS from
functioning properly. See Buying
New Tires on page 10‑59.
.Operating electronic devices or
being near facilities using radio
wave frequencies similar to the
TPMS could cause the TPMS
sensors to malfunction.
If the TPMS is not functioning it
cannot detect or signal a low tire
condition. See your dealer/retailer
for service if the TPMS malfunction
light and DIC message comes on
and stays on.
TPMS Sensor Matching
Process
Each TPMS sensor has a unique
identification code. Any time you
replace one or more of the TPMS
sensors or rotate the vehicle's tires,
the identification codes 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 inflation pressure
indicated on the tire's sidewall.
To let air-pressure out of a tire you
can use the pointed end of the valve
cap, a pencil-style air pressure
gauge, or a key.
Page 322 of 410

10-56 Vehicle Care
You have one minute to match
the first tire/wheel position, and
five minutes overall, to match all
four tire/wheel positions. If it takes
longer than one minute, to match
the first tire and wheel, or more than
five minutes to match all four tire
and wheel positions, the matching
process stops and you need to
start over.
The TPMS sensor matching
procedure is outlined below:
1. Set the parking brake.
2. Turn the ignition switch toON/RUN with the engine off.
3. Turn the exterior lamp switch from AUTO to OFF four times
within three seconds.
A double horn chirp will
sound and the TPMS low tire
warning light starts flashing.
The double horn chirp and
flashing TPMS warning light
indicates the TPMS matching
process has started. The TPMS warning light should continue
flashing throughout the matching
procedure. The LOW TIRE
message displays on the Driver
Information Center (DIC).
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 10 seconds, then stop and
listen for a single horn chirp. The
single horn chirp should sound
within 15 seconds, confirming
that the sensor identification
code has been matched to this
tire and wheel position. If you
do not hear the confirming
single horn chirp, turn the
ignition switch to LOCK and start
over beginning with Step 2.
6. Proceed to the passenger side front tire, and repeat the
procedure in Step 5. 7. Proceed to the passenger side
rear tire, and repeat the
procedure in Step 5.
8. Proceed to the driver side rear tire, and repeat the procedure in
Step 5.
9. After hearing the confirming horn chirp for the driver side rear tire,
check to see if the TPMS low tire
warning light and the DIC LOW
TIRE messages have turned off.
If yes, the TPMS sensors have
been relearned. Turn the ignition
switch to LOCK/OFF.
If the low tire warning light and
the SERV TPM message on the
DIC are on after completing
Step 5 for the driver side rear
tire, the sensor relearn process
has not been successful. Turn
the ignition switch to LOCK/OFF
and repeat the matching process
beginning with Step 2.
Page 323 of 410

Vehicle Care 10-57
10. Set all four tires to therecommended air pressure
level as indicated on the Tire
and Loading Information label.
11. Put the valve caps back on the valve stems.
Tire Inspection
We recommend that you
regularly inspect your vehicle's
tires, including the spare tire,
if the vehicle has one, for
signs of wear or damage. See
When It Is Time for New Tires
on
page 10‑58
for more information.
Tire Rotation
Tires should be rotated every
5,000 to 8,000 miles (8 000 to
13 000 km). See Scheduled
Maintenance
on page 11‑2. The purpose of a regular tire
rotation is to achieve a uniform
wear for all tires on the vehicle.
This will ensure that the vehicle
continues to perform most like it
did when the tires were new.
The first rotation is the most
important. See
Scheduled
Maintenance
on page 11‑2.
Any time you notice unusual
wear, rotate the tires as soon
as possible and check wheel
alignment. Also check for
damaged tires or wheels.
See When It Is Time for New
Tires
on page 10‑58and Wheel
Replacement
on page 10‑63.
Make sure the spare tire is
stored securely. Push, pull and
then try to rotate or turn the tire.
If it moves, use the wheel
wrench/hoist shaft to tighten the
cable. See If a Tire Goes Flat
on
page 10‑64
.
When rotating the vehicle's tires,
always use the correct rotation
pattern shown here. Do not
include the spare tire in the tire
rotation.
After the tires have been
rotated, adjust the front and rear
inflation pressures as shown on
the Tire and Loading Information
label. See Tire Pressure
on
page 10‑51
and Vehicle Load
Limits
on page 9‑27.
Page 324 of 410

10-58 Vehicle Care
Reset the Tire Pressure Monitor
System. SeeTire Pressure
Monitor Operation
on page 10‑53.
Make certain that all wheel nuts
are properly tightened. See
“Wheel Nut Torque” under
Capacities and Specifications
on
page 12‑2
.
{WARNING
Rust or dirt on a wheel, or on the
parts to which it is fastened, can
make wheel nuts become loose
after time. The wheel could come
off and cause an accident. When
changing a wheel, remove any
rust or dirt from places where the
wheel attaches to the vehicle. In
an emergency, use a cloth or a
paper towel to do this; but be sure
to use a scraper or wire brush
later, if needed, to get all the rust
or dirt off. See If a Tire Goes Flat
on page 10‑64.
When It Is Time for New
Tires
Various factors, such as
maintenance, temperatures, driving
speeds, vehicle loading, and road
conditions influence when you need
new tires.
One way to tell when it is time for
new tires is to check the treadwear
indicators, which appear when the
tires have only 1.6 mm (1/16 inch) or
less of tread remaining. The vehicle needs new tires if any
of the following statements are true:
.You can see the indicators at
three or more places around
the tire.
.You can see cord or fabric
showing through the tire's
rubber.
.The tread or sidewall is cracked,
cut, or snagged deep enough to
show cord or fabric.
.The tire has a bump, bulge,
or split.
.The tire has a puncture, cut,
or other damage that cannot be
repaired well because of the size
or location of the damage.
Page 325 of 410

Vehicle Care 10-59
The rubber in tires degrades over
time. This is also true for the spare
tire, if the vehicle has one, even
if it is not being used. Multiple
conditions affect how fast this
aging takes place, including
temperatures, loading conditions,
and inflation pressure maintenance.
With proper care and maintenance
tires typically wear out before they
degrade due to age. If you are
unsure about the need to replace
the tires as they get older, consult
the tire manufacturer for more
information.
Buying New Tires
GM has developed and matched
specific tires for your vehicle.
The original equipment tires
installed on your vehicle, when
it was new, were designed tomeet General Motors Tire
Performance Criteria
Specification (TPC spec)
system rating. If you need
replacement tires, GM strongly
recommends that you get tires
with the same TPC Spec rating.
This way, your vehicle will
continue to have tires that are
designed to give the same
performance and vehicle safety,
during normal use, as the
original tires.
GM's exclusive TPC Spec
system considers over a
dozen critical specifications that
impact the overall performance
of your vehicle, including brake
system performance, ride and
handling, traction control, and
tire pressure monitoring
performance. GM's TPC Spec
number is molded onto the tire's
sidewall near the tire size. If the
tires have an all‐season tread
design, the TPC spec number
will be followed by a MS, for
mud and snow. See
Tire
Sidewall Labeling
on page 10‑44
for additional information.
GM recommends replacing tires
in sets of four. This is because
uniform tread depth on all tires
will help keep your vehicle
performing most like it did when
the tires were new. Replacing
less than a full set of tires can
affect the braking and handling
performance of your vehicle.
Page 326 of 410

10-60 Vehicle Care
SeeTire Inspectionon page 10‑57
andTire Rotationon page 10‑57
for information on proper tire
rotation.
{WARNING
Mixing tires could cause you
to lose control while driving.
If you mix tires of different
sizes, brands, or types
(radial and bias-belted tires)
the vehicle may not handle
properly, and you could have
a crash. Using tires of different
sizes, brands, or types may
also cause damage to your
vehicle. Be sure to use the
correct size, brand, and type
of tires on your vehicle's
wheels.
{WARNING
If you use bias-ply tires on the
vehicle, the wheel rim flanges
could develop cracks after
many miles of driving. A tire
and/or wheel could fail
suddenly, causing a crash.
Use only radial-ply tires with
the wheels on the vehicle.
If you must replace your
vehicle's tires with those that do
not have a TPC Spec number,
make sure they are the same
size, load range, speed rating,
and construction type (radial
and bias‐belted tires) as your
vehicle's original tires.
Vehicles equipped with a tire
pressure monitoring system may
give an inaccurate low‐pressure
warning if non‐TPC spec rated
tires are installed on your
vehicle. Non‐TPC Spec rated tires may give a low‐pressure
warning that is higher or lower
than the proper warning level
you would get with TPC Spec
rated tires. See
Tire Pressure
Monitor System
on page 10‑52.
Your vehicle's original
equipment tires are listed
on the Tire and Loading
Information Label. See Vehicle
Load Limits
on page 9‑27, for
more information about the Tire
and Loading Information Label
and its location on your vehicle.
Different Size Tires and
Wheels
If you add wheels or tires that are
a different size than your original
equipment wheels and tires, this
could affect the way your vehicle
performs, including its braking,
ride and handling characteristics,
stability, and resistance to rollover.
Page 327 of 410

Vehicle Care 10-61
Additionally, if your vehicle has
electronic systems such as anti‐lock
brakes, rollover airbags, traction
control, and electronic stability
control, the performance of these
systems can be affected.
{WARNING
If you add different sized
wheels, your vehicle may not
provide an acceptable level of
performance and safety if tires not
recommended for those wheels
are selected. You may increase
the chance that you will crash and
suffer serious injury. Only use
Hummer specific wheel and tire
systems developed for your
vehicle, and have them properly
installed by a GM certified
technician.
See Buying New Tires
on
page 10‑59and Accessories and
Modificationson page 10‑3for
additional information.
Uniform Tire Quality
Grading
Quality grades can be found
where applicable on the tire
sidewall between tread shoulder
and maximum section width. For
example:
Treadwear 200 Traction AA
Temperature A
The following information relates
to the system developed by the
United States National Highway
Traffic Safety Administration
(NHTSA), which grades tires
by treadwear, traction, and
temperature performance. This
applies only to vehicles sold in
the United States. The grades
are molded on the sidewalls
of most passenger car tires.
The Uniform Tire Quality
Grading (UTQG) system
does not apply to deep
tread, winter-type snow tires, space-saver, or temporary use
spare tires, tires with nominal
rim diameters of 10 to 12 inches
(25 to 30 cm), or to some
limited-production tires.
While the tires available on
Hummer light trucks may vary
with respect to these grades,
they must also conform to
federal safety requirements and
additional General Motors Tire
Performance Criteria (TPC)
standards.
All Passenger Car Tires Must
Conform to Federal Safety
Requirements In Addition To
These Grades.
Treadwear
The treadwear grade is a
comparative rating based
on the wear rate of the tire
when tested under controlled
conditions on a specified
government test course.
Page 328 of 410

10-62 Vehicle Care
For example, a tire graded 150
would wear one and a half (1½)
times as well on the government
course as a tire graded 100.
The relative performance of
tires depends upon the actual
conditions of their use, however,
and may depart significantly
from the norm due to variations
in driving habits, service
practices and differences in
road characteristics and climate.
Traction–AA, A, B, C
The traction grades, from
highest to lowest, are AA, A, B,
and C. Those grades represent
the tire's ability to stop on wet
pavement as measured under
controlled conditions on
specified government test
surfaces of asphalt and
concrete. A tire marked C may
have poor traction performance. Warning: The traction grade
assigned to this tire is based
on straight-ahead braking
traction tests, and does not
include acceleration, cornering,
hydroplaning, or peak traction
characteristics.
Temperature
–A, B, C
The temperature grades are
A (the highest), B, and C,
representing the tire's resistance
to the generation of heat and
its ability to dissipate heat
when tested under controlled
conditions on a specified indoor
laboratory test wheel. Sustained
high temperature can cause
the material of the tire to
degenerate and reduce tire life,
and excessive temperature
can lead to sudden tire failure.
The grade C corresponds to a
level of performance which all
passenger car tires must meet
under the Federal Motor Safety Standard No. 109. Grades B
and A represent higher levels of
performance on the laboratory
test wheel than the minimum
required by law. Warning: The
temperature grade for this tire is
established for a tire that is
properly inflated and not
overloaded. Excessive speed,
underinflation, or excessive
loading, either separately or in
combination, can cause heat
buildup and possible tire failure.
Wheel Alignment and Tire
Balance
The tires and wheels on the vehicle
were aligned and balanced carefully
at the factory to give the longest tire
life and best overall performance.
Adjustments to wheel alignment and
tire balancing will not be necessary
on a regular basis. However, if there
is unusual tire wear or the vehicle
pulls to one side or the other, the
alignment should be checked.