2007 PONTIAC GRAND PRIX wheel

(G) 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.
Tire Size
The following illustration shows an example of a
typical passenger vehicle 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.
(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 60,
as shown in item C of the illustration, it would
mean that the tire’s sidewall is 60 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:These characters
represent the load range and speed rating of the
tire. The load index represents the load carry
capacity a tire is certied to carry. The load index
can range from 1 to 279. The speed rating is
the maximum speed a tire is certied to carry a
load. Speed ratings range from A to Z.
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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 under-inated. 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.
Re-check 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
The Tire Pressure Monitor System (TPMS) uses
radio and sensor technology to check tire pressure
levels. If your vehicle has this feature, sensors
are mounted onto each tire and wheel assembly,
except for the spare tire. The TPMS sensors
monitor the air pressure in your vehicle’s tires and
transmit 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 symbol on the instrument panel cluster,
and at the same time a warning message to check
the pressure in a specic tire displays on the
Driver Information Center (DIC). The low
tire pressure warning light and the DIC warning
message CHECK TIRE PRESSURE come
on at each ignition cycle until the tires are inated
to the correct ination pressure.
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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 317, for an
example of the Tire and Loading Information
label and its location on your vehicle. Also see
Ination - Tire Pressure on page 408.
Your vehicle’s TPMS system can warn you about
a low tire pressure condition but it does not
replace normal tire maintenance. SeeTire
Inspection and Rotation on page 414andTires on
page 400.
Notice:Do not use a tire sealant if your
vehicle has Tire Pressure Monitors. The liquid
sealant can damage the tire pressure monitor
sensors.
The TPMS will not function properly if one or more
of the TPMS sensors are missing or inoperable.
If the system detects a missing or inoperable
sensor, an error message SERVICE TIRE
MONITOR SYSTEM appears on the DIC display.
If you have replaced a tire/wheel assembly
without transferring the TPMS sensors, the error
message displays. Once you re-install the
TPMS sensors, the error message should go off.
See your dealer for service if all TPMS sensors
are installed and the error message comes on and
stays on.
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TPMS Sensor Identication Codes
Each TPMS sensor has a unique identication
code. Any time you replace one or more of
the TPMS sensors or rotate the vehicle’s tires,
the identication 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 for service.
The TPMS sensors may also be matched to each
tire/wheel position by increasing or decreasing
the tire’s air pressure. When increasing the tire’s
pressure, do not exceed the maximum ination
pressure indicated on the tire’s sidewall.
You have two minutes to match each tire and
wheel position. If it takes longer than two minutes
to match any tire and wheel position, the
matching process stops and you need to
start over.The TPMS matching process is outlined below:
1. Set the parking brake.
2. Turn the ignition switch to RUN with the
engine off.
3. Press the Remote Keyless Entry (RKE)
transmitter’s Lock and Unlock buttons at
the same time for approximately ve seconds.
The horn sounds twice to signal the receiver
is in relearn mode and the TPMS sensor
matching process can begin.
4. Start with the driver’s side front tire.
5. Remove the valve cap from the tire’s valve
stem. Activate the TPMS sensor by
increasing or decreasing the tire’s air
pressure for ten seconds, or until a horn
chirp sounds. The horn chirp, which
may take up to 30 seconds to sound,
conrms that the sensor identication code
has been matched to the tire/wheel
position. To decrease the tire’s air-pressure
use the pointed end of the valve cap,
a pencil-style air pressure gage, or a key.
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Tire Inspection and Rotation
Tire rotation is not recommended if your vehicle is
a GXP model equipped with P255/45R18 size
tires on the front wheels and P225/50R18 size tires
on the rear wheels. Different tire sizes front to
rear should not be rotated.
Tire rotation is recommended if the original
equipment tires installed on your vehicle are
of the same size and type on all four tire/wheel
positions. Original equipment tires of the
same size and type should be rotated every
5,000 to 8,000 miles (8 000 to 13 000 km).
Any time you notice unusual wear, rotate your
vehicle’s tires as soon as possible and check the
wheel alignment. Also check for damaged tires
or wheels. SeeWhen It Is Time for New Tires on
page 415andWheel Replacement on page 419
for more information.
The purpose of regular rotation is to achieve more
uniform wear for all tires on the vehicle. The
rst rotation is the most important. SeeScheduled
Maintenance on page 473for scheduled rotation
intervals.The correct rotation pattern shown here is only for
non-GXP tires.
Do not include the compact spare tire, if equipped,
in your vehicle’s tire rotation.
After the tires have been rotated, adjust the front
and rear ination pressures as shown on the Tire
and Loading Information label, and reset the Tire
Pressure Monitor System. SeeTire Pressure
Monitor System on page 409for additional
information.
Rotation Pattern for Non-GXP Tires Only
414

Make certain that all wheel nuts are properly
tightened. See “Wheel Nut Torque” under
Capacities and Specications on page 466.
{CAUTION:
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
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 needed, to get all the rust or dirt
off. SeeChanging a Flat Tire on page 435.
When It Is Time for New Tires
One way to tell when it
is 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 cannot be repaired well because of the
size or location of the damage.
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Buying New Tires
GM has developed and matched specic tires for
your vehicle. The original equipment tires
installed on your vehicle, when it was new, were
designed to meet General Motors Tire
Performance Criteria Specication (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 specications 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 by the tire manufacturer.
If the tires have an all-season tread design,
the TPC spec number will be followed by an MS
for mud and snow. SeeTire Sidewall Labeling
on page 401for additional information.{CAUTION:
Mixing tires could cause you to lose
control while driving. If you mix tires of
different sizes (other than those originally
installed on your vehicle), 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 (other than those originally
installed on your vehicle) may also cause
damage to your vehicle. Be sure to use
the correct size, brand, and type tires on
all wheels. If your vehicle has a compact
spare tire, it is all right to drive your
vehicle with the compact spare
temporarily. It was developed for use on
your vehicle. SeeCompact Spare Tire on
page 447.
416

{CAUTION:
If you use bias-ply tires on your vehicle,
the wheel rim anges 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.
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.
Your vehicle’s original equipment tires are listed on
the Tire and Loading Information label. This
label is attached to the vehicle’s center pillar
(B-pillar). SeeLoading Your Vehicle on page 317,
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 may affect the way your vehicle performs,
including its braking, ride and handling
characteristics, stability, and resistance to rollover.
Additionally, if your vehicle has electronic
systems such as, anti-lock brakes, traction control,
and electronic stability control, the performance
of these systems can be affected.
{CAUTION:
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 GM specic wheel and
tire systems developed for your vehicle,
and have them properly installed by a GM
certied technician.
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