2003 CHEVROLET IMPALA tires

Tire Pressure Monitor System
If your vehicle has the tire pressure monitor system, it
can alert you to a large change in the pressure of
one tire. The system ªlearnsº the pressure at each tire
throughout the operating speed range of your vehicle.
The system normally takes between 45 and 90 minutes
of driving to learn the tire pressures. This time may
be longer depending on your individual driving habits.
Learning need not be accumulated during a single
trip. Once learned, the system will remember the tire
pressures until the system is recalibrated.
After the system has learned tire pressures with
properly in¯ated tires, the LOW TIRE PRESSURE
message will come on if the pressure in one tire
becomes 12 psi (83 kPa) lower than the other three
tires. The tire pressure monitor system won't alert you if
the pressure in more than one tire is low, if the
system is not properly calibrated, or if the vehicle is
moving faster than 70 mph (110 km/h).
The tire pressure monitor system detects differences in
tire rotation speeds that are caused by changes in
tire pressure. The system can alert you about a low
tire Ð but it doesn't replace normal tire maintenance.
See
Tires on page 5-61.When the LOW TIRE PRESSURE message comes on,
you should stop as soon as you can and check all
your tires for damage. (If a tire is ¯at, see
If a Tire Goes
Flat on page 5-71.) Also check the tire pressure in all
four tires as soon as you can. SeeIn¯ation -- Tire
Pressure on page 5-62.
The LOW TIRE PRESSURE message will also be
displayed (while the ignition is on) until you reset
(calibrate) the system.
Don't reset the tire pressure monitor system without ®rst
correcting the cause of the problem and checking
and adjusting the pressure in all four tires. If you reset
the system when the tire pressures are incorrect,
the system will not work properly and may not alert you
when a tire is low.
Any time you adjust a tire's pressure, rotate your tires,
or have one or more tires repaired or replaced, you'll
need to reset (calibrate) the tire pressure monitor
system. You'll also need to reset the system whenever
you buy new tires and whenever the vehicle's battery
has been disconnected.
To reset (calibrate) the system: The tire pressure
monitor system can be reset two ways. With the ignition
position at ON, pull the interior lamps control to the
ON and OFF settings three times.
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It can also be reset through the radio using the following
steps:
1. Turn the ignition to ACC or ON and turn the radio
off.
2. Press and hold the TUNE DISP button on the radio
for at least ®ve seconds until SETTINGS is
displayed.
3. Press the SEEK SCAN up or down arrow to scroll
through the main menu.
4. Scroll until TIRE MON appears on the display.
5. Press the 1 PREV or 2 NEXT button to enter the
submenu. RESET will be displayed.
6. Press the TUNE DISP button to reset. A chime will
be heard to verify the new setting and DONE will
be displayed for one second.
7. Once the monitor has been reset, scroll until EXIT
appears on the display.
8. Press the TUNE DISP button to exit programming.
A chime will be heard to verify exit.The system completes the calibration process
during driving.
The system normally takes 15 to 20 minutes of driving
in each of three speed ranges to²learn²tire pressures.
The speed ranges are 15 to 4 mph (25 to 65 km/h),
40 to 65 mph (65 to 105 km/h) and above 65 mph
(105 km/h). When learning is complete, the system will
alert you after two to eight minutes if a tire is 12 psi
(83 kPa) different from the other three tires. Detection
thresholds may be higher and detection times may
be longer on rough roads, curves and at high speeds.
The system is not capable of detection at speeds greater
than 70 mph (110 km/h).
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Tire Inspection and Rotation
Tires should be rotated every 7,500 miles (12 500 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 5-66andWheel Replacement
on page 5-69for 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. See ªPart A: Scheduled
Maintenance Services,º in Section 6, 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 in¯ation pressures as shown on the Tire-Loading
Information label.
Reset the Tire In¯ation Monitor System. See
Tire
Pressure Monitor System on page 5-63.
Make certain that all wheel nuts are properly tightened.
See ªWheel Nut Torqueº under
Capacities and
Speci®cations on page 5-103.
{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.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.
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Buying New Tires
To ®nd 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 Speci®cation (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 temporarily, it was developed
for use on your vehicle. See ªCompact Spare
Tireº in the index.
{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.
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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 speci®ed government test course.
For example, a tire graded 150 would wear one and
a half (1.5) 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 signi®cantly 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 speci®ed 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.
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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 speci®ed 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 in¯ated and not
overloaded. Excessive speed, underin¯ation, 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.
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Each new wheel should have the same load-carrying
capacity, diameter, width, offset and be mounted
the same way as the one it replaces.
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
Changing a Flat Tire on page 5-72for 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 a crash. If you have to
replace a wheel, use a new GM original
equipment wheel.
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