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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.
There are 6.9 kPa's to one psi.
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 In¯ation Pressure:The maximum air
pressure to which a cold tire may be in¯ated. The
maximum air pressure is molded onto the sidewall.
Maximum Load Rating:The load rating for a tire at the
maximum permissible in¯ation 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 pounds
(68 kg). See
Loading Your Vehicle on page 4-44.Occupant Distribution:Designated seating positions.
Outward Facing Sidewall:The side of a 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 In¯ation Pressure:Vehicle
manufacturer's recommended tire in¯ation pressure and
shown on the tire placard. See
In¯ation - Tire Pressure
on page 5-62andLoading Your Vehicle on page 4-44.
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.
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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 ªwear bars,º that show across the tread of a tire
when only 2/32 inch of tread remains. See
When It
Is Time for New Tires on page 5-68.
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. See
Uniform Tire Quality
Grading on page 5-69.Vehicle Capacity Weight:The number of designated
seating positions multiplied by 150 lbs. (68 kg) plus
the rated cargo load. See
Loading Your Vehicle
on page 4-44.
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 original equipment tire size
and recommended in¯ation pressure. See
Loading Your
Vehicle on page 4-44.
In¯ation - Tire Pressure
The tire and loading information label, shows the correct
in¯ation pressures for your tires when they're cold.
ªColdº means your vehicle has been sitting for at least
three hours or driven no more than 1 mile (1.6 km).
See
Loading Your Vehicle on page 4-44, for the location
of your vehicle's tire and loading information label.
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Notice:Don't let anyone tell you that underin¯ation
or overin¯ation is all right. It's not. If your tires
don't have enough air (underin¯ation), you can get
the following:
·Too much ¯exing
·Too much heat
·Tire overloading
·Bad wear
·Bad handling
·Bad fuel economy
If your tires have too much air (overin¯ation), you
can get the following:
·Unusual wear
·Bad handling
·Rough ride
·Needless damage from road hazards
When to Check
Check your tires once a month or more.
Also, check the tire pressure of the spare tire.
How to Check
Use a good quality pocket-type gage to check tire
pressure. You can't tell if your tires are properly in¯ated
simply by looking at them. Radial tires may look
properly in¯ated even when they're underin¯ated. Check
the tire's in¯ation 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 in¯ation pressure matches
the recommended pressure on the tire and loading
information label, no further adjustment is necessary.
If the pressure is low, add air until you reach the
recommended amount.
If you over®ll 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.
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Page 372 of 468

Tire Pressure Monitor System
The Tire Pressure Monitor (TPM) system uses radio
and sensor technology to check tire pressure levels.
If your vehicle has this feature, sensors are mounted on
each tire and wheel assembly, except the spare tire.
The TPM sensors transmit tire pressure readings
to a receiver located in the vehicle.
When a low tire pressure condition is detected, the TPM
system will display the CHECK TIRE PRESSURE
warning message on the Driver Information Center
(DIC); and at the same time illuminate the low tire
pressure warning symbol. For additional information and
details about the DIC operation and displays see DIC
Operation and Displays on page 3-46andDIC Warnings
and Messages on page 3-57.
When the tire pressure
monitoring system warning
light is lit, one or more
of your tires is signi®cantly
under-in¯ated.
You should stop and check your tires as soon as
possible, and in¯ate them to the proper pressure as
indicated on the vehicle's tire information placard.Driving on a signi®cantly under-in¯ated tire causes the
tire to overheat and can lead to tire failure.
Under-in¯ation also reduces fuel efficiency and tire tread
life, and may affect the vehicle's handling and stopping
ability. Each tire, including the spare, should be
checked monthly when cold and set to the
recommended in¯ation pressure as speci®ed in the
vehicle placard and owner's manual.
The Certi®cation/Tire label or the Tire and Loading
Information label (tire information placard) shows the
size of your vehicle's original tires and the correct
in¯ation pressure for your vehicle's tires when they are
cold. See
In¯ation - Tire Pressure on page 5-62. For
the location of the tire and loading information label, see
Loading Your Vehicle on page 4-44.
Your vehicle's TPM system can alert you about a low
tire pressure condition but it does not replace normal tire
maintenance. See
Tire Inspection and Rotation on
page 5-66andTires on page 5-54.
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.
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TPM Sensor Identi®cation Codes
Each TPM sensor has a unique identi®cation code.
Any time you rotate your vehicle's tires or replace one
or more of the TPM sensors, the identi®cation codes will
need to be matched to the new tire/wheel position.
Each tire/wheel position is matched to a sensor,
by increasing or decreasing the tire's air pressure.
The sensors are matched to the tire/wheel positions in
the following order: left front (LF); right front (RF);
right rear (RR) and left rear (LR).
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 TPM sensor matching process is outlined below:
1. Set the Parking brake.
2. Turn the ignition switch to RUN with the engine off.
3. Turn the exterior lamp switch from ªOffº to ªOnº
four times within 3 seconds. A double horn chirp
will sound and the TPM low tire warning light
will begin to ¯ash. The double horn chirp and¯ashing TPM warning light indicate that the TPM
matching process has started. The TPM warning
light should continue ¯ashing throughout the
matching procedure. The SERVICE TIRE
MONITOR message will be displayed on the Driver
Information Center (DIC).
4. Start with the left (driver's side) front tire.
5. Remove the valve cap from the valve cap stem.
Activate the TPM 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, con®rming that the sensor identi®cation
code has been matched to this tire and wheel
position. If you do not hear the con®rming 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 pointy end of the valve cap, a pencil-style
air pressure gage or a key.
6. Proceed to the right (passenger's side) front tire,
and repeat the procedure in step 5.
7. Proceed to the right (passenger's side) rear tire,
and repeat the procedure in step 5.
8. Proceed to the left (driver's side) rear tire, and
repeat the procedure in step 5.
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9. After hearing the con®rming horn chirp for the left
rear tire, check to see if the TPM warning light is
still ¯ashing. If yes, turn the ignition switch to OFF.
10. Set all four tires to the recommended air pressure
level as indicated on the Certi®cation/Tire label or
the Tire and Loading Information label.
11. Put the valve caps back on the valve stems
The spare tire does not have a TPM sensor. If you
replace one of the road tires with the spare, the CHECK
TIRE PRESSURE message will be displayed on the DIC
screen. This message should go off once you re-install
the road tire containing the TPM sensor. The SERVICE
TIRE MONITOR message is displayed when the TPM
system is malfunctioning. One or more missing or
inoperable TPM sensors will cause the service tire
monitor message to be displayed. See your dealer for
service.
Federal Communications Commission and
Industry and Science Canada
The TPM system operates on a radio frequency subject
to Federal Communications Commission (FCC) Rules
and with Industry and Science Canada.
This device complies with Part 15 of the FCC Rules and
with RSS-210 of Industry and Science Canada.
Operation is subject to the following two conditions:
(1) This device may not cause harmful interference, and(2) this device must accept any interference received
including interference that may cause undesired
operation of the device.
Changes or modi®cations to this system by other than
an authorized service facility could void authorization to
use this equipment.
Tire Inspection and Rotation
Tires should be rotated every 5,000 to 8,000 miles
(8 000 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
When It Is Time
for New Tires on page 5-68andWheel Replacement
on page 5-71for more information.
Make sure the spare tire is stored securely. Push, pull,
and then try to rotate or turn the tire. If it moves,
use the ratchet/wheel wrench to tighten the cable.
See
Changing a Flat Tire on page 5-74.
The purpose of regular rotation is to achieve more
uniform wear for all tires on the vehicle. The ®rst rotation
is the most important. See
Scheduled Maintenance
on page 6-4.
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When rotating your tires, always use the correct rotation
pattern shown here.
Do not include the spare tire in your tire rotation.
After the tires have been rotated, adjust the front and
rear in¯ation pressures as shown on the tire and loading
information label. See
Loading Your Vehicle on
page 4-44andIn¯ation - Tire Pressure on page 5-62,
for more information. Make certain that all wheel
nuts are properly tightened. See ªWheel Nut Torqueº
under
Capacities and Speci®cations on page 5-112.
If your vehicle has the Tire Pressure Monitor (TPM)
system, the sensors will need to be reset after a
tire rotation is performed. See ªTPM Sensor
Identi®cation Codesº under
Tire Pressure Monitor
System on page 5-64.
{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.
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When It Is 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. Some
commercial truck tires may
not have treadwear
indicators.
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.
Buying New Tires
To ®nd out what kind and size of tires you need, look at
the Certi®cation/Tire label or the Tire and Loading
Information label. See
Loading Your Vehicle on
page 4-44, for more information about these labels and
where they can be found on your vehicle.
The tires installed on your vehicle when it was new had
a Tire Performance Criteria Speci®cations (TPC
Spec) number on each tire's sidewall. When you get
new tires, GM recommends that you get tires 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, load range,
traction, ride, tire pressure monitoring system
performance 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).
When ever you 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.
If you replace your vehicle's tires with those not having a
TPC Spec number, the tire pressure monitoring
system may give an inaccurate low pressure warning.
Non-TPC Spec tires may give a low pressure warning
that is higher or lower than the proper warning level you
would get with TPC Spec numbered tires.
5-68