2004 CHEVROLET IMPALA Owners Manual

(A) Temporary Use Only:The compact spare tire or
temporary use tire has a tread life of approximately
3,000 miles (5 000 km) and should not be driven
at speeds over 65 mph (105 km/h). The compact spare
tire is for emergency use when a regular road tire
has lost air and gone at. SeeCompact Spare Tire on
page 5-93andIf a Tire Goes Flat on page 5-81.
(B) Tire Ply Material:The type of cord and number of
plies in the sidewall and under the tread.
(C) Tire Identication Number (TIN):The Tire
Identication Number (TIN). The TIN shows the
manufacturer and plant code, tire size, and date the
tire was manufactured. The TIN is molded onto
both sides of the tire, although only one side may have
the date of manufacture.
(D) Maximum Cold Ination Load Limit:Maximum
load that can be carried and the maximum pressure
needed to support that load. SeeCompact Spare Tire
on page 5-93andLoading Your Vehicle on page 4-32.(E) Tire Ination:The temporary use tire or compact
spare tire should be inated to 60 psi (420 kPa).
For more information on tire pressure and ination
seeInation - Tire Pressure on page 5-72.
(F) Tire Size:A combination of letters and numbers
dene a tire’s width, height, aspect ratio, construction
type and service description. The letter “T” as the
rst character in the tire size means the tire is for
temporary use only.
(G) Tire Performance Criteria Specication
(TPC Spec):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.
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Tire Size
The following illustration shows an example of a typical
passenger car tire size.
(A) 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 “70,” as shown in item “C”
of the illustration, it would mean that the tire’s sidewall
is 70% 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 the speed rating of a tire. The load
range represents the load carrying 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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Tire Terminology and Denitions
Air Pressure:The amount of air inside the tire pressing
outward on each square inch of the tire. Air pressure
is expressed in pounds per square inch (psi) or
kilopascal (kPa).
Accessory Weight:This means the combined weight
of optional accessories. Some examples of optional
accessories are, automatic transmission, power steering,
power brakes, power windows, power seats, and air
conditioning.
Aspect Ratio:The relationship of a tire’s height to
its width.
Belt:A rubber coated layer of cords that is located
between the plies and the tread. Cords may be made
from steel or other reinforcing materials.
Bead:The tire bead contains steel wires wrapped by
steel cords that hold the tire onto the rim.
Bias Ply Tire:A pneumatic tire in which the plies are
laid at alternate angles less than 90 degrees to the
centerline of the tread.Cold Ination Pressure:The amount of air pressure in
a tire, measured in pounds per square inch (psi) before a
tire has built up heat from driving. SeeInation - Tire
Pressure on page 5-72.
Curb Weight:This means the weight of a motor
vehicle with standard and optional equipment including
the maximum capacity of fuel, oil and coolant, but
without passengers and cargo.
DOT Markings:A code molded into the sidewall of a
tire signifying that the tire is in compliance with the
U.S. Department of Transportation motor vehicle safety
standards. The DOT code includes the Tire Identication
Number (TIN), an alphanumeric designator which can
also identify the tire manufacturer, production plant,
brand and date of production.
GVWR:Gross Vehicle Weight Rating, seeLoading
Your Vehicle on page 4-32.
GAWR FRT:Gross Axle Weight Rating for the front
axle, seeLoading Your Vehicle on page 4-32.
GAWR RR:Gross Axle Weight Rating for the rear axle,
seeLoading Your Vehicle on page 4-32.
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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 Ination Pressure:The maximum air
pressure to which a cold tire may be inated. The
maximum air pressure is molded onto the sidewall.
Maximum Load Rating:The load rating for a tire at the
maximum permissible ination 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). SeeLoading Your Vehicle on page 4-32.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 Ination Pressure:Vehicle
manufacturer’s recommended tire ination pressure and
shown on the tire placard. SeeInation - Tire Pressure
on page 5-72andLoading Your Vehicle on page 4-32.
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 “wear bars,” that show across the tread of a tire
when only 2/32 inch of tread remains. SeeWhen It
Is Time for New Tires on page 5-76.
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. SeeUniform Tire Quality
Grading on page 5-77.Vehicle Capacity Weight:The number of designated
seating positions multiplied by 150 lbs. (68 kg) plus
the rated cargo load. SeeLoading Your Vehicle
on page 4-32.
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 ination pressure. SeeLoading Your
Vehicle on page 4-32.
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Ination - Tire Pressure
The tire and loading information label, shows the correct
ination pressures for your tires when they’re cold.
“Cold” means your vehicle has been sitting for at least
three hours or driven no more than 1 mile (1.6 km).
SeeLoading Your Vehicle on page 4-32, for the location
of your vehicle’s tire and loading information label.
Notice:Don’t let anyone tell you that underination
or overination is all right. It’s not. If your tires
don’t have enough air (underination), 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 (overination),
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.
Don’t forget your compact spare tire. It should be at
60 psi (420 kPa).
How to Check
Use a good quality pocket-type gage to check tire
pressure. You can’t tell if your tires are properly inated
simply by looking at them. Radial tires may look
properly inated even when they’re underinated.
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. 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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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 “learns” 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 inated 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 — but it doesn’t replace normal tire maintenance.
SeeTires on page 5-64.
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, seeIf a Tire Goes
Flat on page 5-81.) Also check the tire pressure in all
four tires as soon as you can. SeeInation - Tire
Pressure on page 5-72.
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.
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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.
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 to “learn” tire pressures.
The speed ranges are 15 to 40 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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