6-49
Changes or modifications to this system by other than an
authorized service facility could void authorization to
use this equipment.
If the TPM system detects low tire pressure, below
24 psi (165 kPa), or high tire pressure, above 36 psi
(248 kPa), a message, CHECK TIRE PRESSURE, will
appear on the Driver Information Center (DIC) display.
By pressing the INFO button, the DIC screen will show
which tire(s) has the low or high pressure condition.
See ªInflation
-- Tire Pressureº in the Index for
information regarding correct tire inflation. If a tire is
low, you should stop as soon as possible and check all
your tires for damage. If a tire is flat, see ªIf a Tire
Goes Flatº in the Index.
NOTICE:
Do not use a tire sealant if your vehicle is equipped
with Tire Pressure Monitors. The liquid sealant
can damage the tire pressure monitor sensors.
Once a low or high tire pressure condition is detected,
the TPM system will display the CHECK TIRE
MESSAGE each time the engine is started, until the
tire(s) are set to the correct inflation pressure. The Certification/Tire Label, which is located on the
rear edge of the driver's side rear door, shows the
correct inflation pressure for the tires on your vehicle.
The TPM system also allows the driver to check the
air pressure status of each road tire using the Driver
Information Center (DIC). Each tire's air pressure will be
listed individually, in the following order: LF (left front
or driver's side front tire), RF (right front or passenger's
side front tire), RR (right rear or passenger's side
rear tire) and LR (left rear or driver's side rear tire).
See ªInflation
-- Tire Pressureº in the Index for
information regarding correct tire inflation. Also, see
ªDriver Information Center (DIC)º in the Index for
information on the DIC controls and displays.
If the DIC display doesn't show tire pressures or the
SERVICE TPM SYSTEM message appears, see your
dealer for service. The TPM system may not work
properly while the compact spare tire is installed.
Anytime you replace one or more tires or rotate your
tires the TPM system will need to be reset. A special
tool is needed to reset the sensor identification codes.
See your dealer for service.
The TPM system can alert you about a low or high
tire pressure condition, but it doesn't replace normal
tire maintenance. See ªTiresº in the Index.
6-50 Tire Inspection and Rotation
Tires should be rotated every 6,000 to 8,000 miles
(10 000 to 13 000 km). Any time you notice unusual
wear, rotate your tires as soon as possible and check
wheel alignment. Also check for damaged tires or
wheels. See ªWhen It's Time for New Tiresº and
ªWheel Replacementº later in this section for
more information.
The purpose of regular rotation is to achieve more
uniform wear for all tires on the vehicle. The first
rotation is the most important. See ªScheduled
Maintenance Servicesº in the Maintenance Schedule
booklet for scheduled rotation intervals.
When rotating your tires, always use the correct rotation
pattern shown here.Don't include the compact spare tire in your tire rotation.
After the tires have been rotated, adjust the front and
rear inflation pressures as shown on the Tire
-Loading
Information label. Vehicles equipped with the Tire
Pressure Monitor (TPM) system will need to have the
sensors reset after a tire rotation is performed. A special
tool is needed to reset the sensor identification codes.
See your dealer for service. Make certain that all wheel
nuts are properly tightened. See ªWheel Nut Torqueº
in the Index.
CAUTION:
Rust or dirt on a wheel, or on the parts to which
it is fastened, can make wheel nuts become loose
after a time. The wheel could come off and cause
an accident. When you change a wheel, remove
any rust or dirt from places where the wheel
attaches to the vehicle. In an emergency,
you can use a cloth or a paper towel to do this;
but be sure to use a scraper or wire brush later,
if you need to, to get all the rust or dirt off.
See ªChanging a Flat Tireº in the Index.
6-51
When It's Time for New Tires
One way to tell when it's
time for new tires is to
check the treadwear
indicators, which will
appear when your tires have
only 1/16 inch (1.6 mm) or
less of tread remaining.You need a new tire 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
can't be repaired well because of the size or location
of the damage.
6-52 Buying New Tires
To find out what kind and size of tires you need, look at
the Tire
-Loading Information label.
The tires installed on your vehicle when it was new had
a Tire Performance Criteria Specification (TPC Spec)
number on each tire's sidewall. When you get new tires,
get ones with that same TPC Spec number. That way
your vehicle will continue to have tires that are designed
to give proper endurance, handling, speed rating,
traction, ride and other things during normal service on
your vehicle. If your tires have an all
-season tread
design, the TPC number will be followed by
an ªMSº (for mud and snow).
If you ever replace your tires with those not having a
TPC Spec number, make sure they are the same
size, load range, speed rating and construction
type (bias, bias
-belted or radial) as your original tires.
CAUTION:
Mixing tires could cause you to lose control while
driving. If you mix tires of different sizes or types
(radial and bias
-belted tires), the vehicle may not
handle properly, and you could have a crash.
Using tires of different sizes may also cause
damage to your vehicle. Be sure to use the same
size and type tires on all wheels.
It's all right to drive with your compact spare,
though. It was developed for use on your vehicle.
CAUTION:
If you use bias-ply tires on your 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 your vehicle.
6-53 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, 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
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 General Motors passenger
cars and 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.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.
For example, a tire graded 150 would wear one and
a half (1 1/2) 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.
6-54
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 Vehicle 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 wheels on your vehicle were aligned and balanced
carefully at the factory to give you the longest tire life
and best overall performance.
Scheduled wheel alignment and wheel balancing are not
needed. However, if you notice unusual tire wear or
your vehicle pulling one way or the other, the alignment
may need to be reset. If you notice your vehicle
vibrating when driving on a smooth road, your wheels
may need to be rebalanced.
Wheel Replacement
Replace any wheel that is bent, cracked, or badly rusted
or corroded. If wheel nuts keep coming loose, the wheel,
wheel bolts and wheel nuts should be replaced. If the
wheel leaks air, replace it (except some aluminum
wheels, which can sometimes be repaired).
See your dealer if any of these conditions exist.
Your dealer will know the kind of wheel you need.
Each new wheel should have the same load
-carrying
capacity, diameter, width, offset and be mounted the
same way as the one it replaces.
6-55
If you need to replace any of your wheels, wheel bolts
or wheel nuts, replace them only with new GM original
equipment parts. This way, you will be sure to have the
right wheel, wheel bolts and wheel nuts for your vehicle.
CAUTION:
Using the wrong replacement wheels, wheel bolts
or wheel nuts on your vehicle can be dangerous.
It could affect the braking and handling of your
vehicle, make your tires lose air and make you
lose control. You could have a collision in which
you or others could be injured. Always use the
correct wheel, wheel bolts and wheel nuts
for replacement.
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.
See ªChanging a Flat Tireº in the Index for
more information.
Used Replacement Wheels
CAUTION:
Putting a used wheel on your vehicle is
dangerous. You can't know how it's been used or
how far it's been driven. It could fail suddenly
and cause an accident. If you have to replace a
wheel, use a new GM original equipment wheel.
6-56 Tire Chains
NOTICE:
If your vehicle has P235/55R17 size tires, don't
use tire chains. They can damage your vehicle
because there's not enough clearance.
Use another type of traction device only if
its manufacturer recommends it for use on
your vehicle and tire size combination and
road conditions.
Follow that manufacturer's instructions. To help
avoid damage to your vehicle, drive slowly,
readjust or remove the device if it's contacting
your vehicle, and don't spin your wheels.
NOTICE: (Continued)
NOTICE: (Continued)
If you do find traction devices that will fit, install
them on the front tires.
If you have other tires, use tire chains only where
legal and only when you must. Use only SAE
Class ªSº type chains that are the proper size for
your tires. Install them on the front 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.