service SATURN ASTRA 2009 Manual Online

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 index and speed rating
of the tire. The load index
represents the load carry
capacity a tire is certied to
carry. The speed rating is the
maximum speed a tire is certied
to carry a load.
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.
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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 Tire Pressure
:The
amount of air pressure in a
tire, measured in pounds
per square inch (psi) or
kilopascals (kPa) before a tire
has built up heat from driving.
SeeInflation - Tire Pressure on
page 9-47.
Curb Weight
: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
(DOT) 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 the Vehicle
on page 8-30.
GAWR FRT
:Gross Axle
Weight Rating for the front axle.
SeeLoading the Vehicle on
page 8-30.
GAWR RR
:Gross Axle
Weight Rating for the rear axle.
SeeLoading the Vehicle on
page 8-30.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.
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 can 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.
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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 lbs (68 kg).
SeeLoading the Vehicle
on page 8-30.
Occupant Distribution
:Designated seating positions.
Outward Facing Sidewall
:The side of an 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 as
shown on the tire placard.
SeeInflation - Tire Pressure
on page 9-47andLoading the
Vehicle on page 8-30.
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.
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
1/16 inch (1.6 mm) of tread
remains. SeeWhen It Is Time
for New Tires on page 9-54.
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 9-57.
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Vehicle Capacity Weight:The number of designated
seating positions multiplied by
150 lbs (68 kg) plus the
rated cargo load. SeeLoading
the Vehicle on page 8-30.
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 vehicle’s
capacity weight and the
original equipment tire size
and recommended ination
pressure. See “Tire and Loading
Information Label” under
Loading the Vehicle on
page 8-30.
Ination - Tire Pressure
Tires need the correct amount of
air pressure to operate effectively.
Notice:Do not let anyone tell
you that under-ination or
over-ination is all right. It is
not. If your tires do not have
enough air (under-ination),
you can get the following:
Too much exing
Too much heat
Tire overloading
Premature or irregular wear
Poor handling
Reduced fuel economy
If your tires have too much air
(over-ination), you can get
the following:
Unusual wear
Poor handling
Rough ride
Needless damage from
road hazardsA vehicle specic Tire and
Loading Information label is
attached to your vehicle.
This label shows your vehicle’s
original equipment tires and
the correct ination pressures for
your tires when they are cold.
The recommended cold tire
ination pressure, shown on the
label, is the minimum amount
of air pressure needed to
support your vehicle’s maximum
load carrying capacity.
For additional information
regarding how much weight your
vehicle can carry, and an
example of the Tire and Loading
Information label, seeLoading
the Vehicle on page 8-30.
How you load your vehicle
affects vehicle handling and ride
comfort. Never load your
vehicle with more weight than it
was designed to carry.
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When to Check
Check your tires once a month
or more. Do not forget to
check the compact spare tire,
it should be at 60 psi (420 kPa).
For additional information
regarding the compact spare
tire, seeCompact Spare Tire
on page 9-68.
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.High-Speed Operation
{CAUTION
Driving at high speeds, 100 mph
(160 km/h) or higher, puts an
additional strain on tires.
Sustained high-speed driving
causes excessive heat build up
and can cause sudden tire failure.
You could have a crash and
you or others could be killed.
Some high-speed rated tires
require ination pressure
adjustment for high speed
operation. When speed limits and
road conditions are such that a
vehicle can be driven at high
speeds, make sure the tires are
rated for high speed operation, in
excellent condition, and set to the
correct cold tire ination pressure
for the vehicle load.
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If the vehicle has P205/55R16 size
tires, additional air pressure is
required when driving the vehicle at
speeds of 99 mph (158 km/h) or
higher. Set the cold tire ination
pressure to the maximum ination
pressure shown on the tire sidewall,
or 32 psi (220 kPa), whichever is
lower. See the example following.
Example:
The maximum load and ination
pressure is molded on the tire’s
sidewall, in small letters, near the rim
ange. It reads something like this:
Maximum load 710 kg (1565 lbs)
350 kPa (51 psi) Max. Press.
For this example, the cold tire
ination pressure for high-speed
driving should be set at 32 psi
(220 kPa).
When high-speed driving ends,
return the tire pressure to the
recommended cold ination
pressure shown on the Tire and
Loading Information label.SeeLoading the Vehicle on
page 8-30. Tire pressure should be
checked and correctly set when
the tires are cold. SeeInflation - Tire
Pressure on page 9-47.
Tire Pressure Monitor
System
The Tire Pressure Monitor System
(TPMS) uses radio and sensor
technology to check tire pressure
levels. The TPMS sensors monitor
the air pressure in your vehicle’s tires
and transmit tire pressure readings to
a receiver located in the vehicle.
Each tire, including the spare
(if provided), should be checked
monthly when cold and inated to
the ination pressure recommended
by the vehicle manufacturer on
the vehicle placard or tire ination
pressure label. (If your vehicle
has tires of a different size than the
size indicated on the vehicle
placard or tire ination pressure
label, you should determine the
proper tire ination pressure
for those tires.)As an added safety feature, your
vehicle has been equipped with
a tire pressure monitoring system
(TPMS) that illuminates a low
tire pressure telltale when one or
more of your tires is signicantly
under-inated.
Accordingly, when the low tire
pressure telltale illuminates, you
should stop and check your tires as
soon as possible, and inate them to
the proper pressure. Driving on a
signicantly under-inated tire
causes the tire to overheat and can
lead to tire failure. Under-ination
also reduces fuel efficiency and
tire tread life, and may affect the
vehicle’s handling and stopping
ability.
Please note that the TPMS is
not a substitute for proper tire
maintenance, and it is the driver’s
responsibility to maintain correct tire
pressure, even if under-ination
has not reached the level to trigger
illumination of the TPMS low tire
pressure telltale.
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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 replacingone 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.
SeeTire Pressure Monitor
Operation on page 9-51for
additional information.
Federal Communications
Commission (FCC) and
Industry and Science Canada
The Tire Pressure Monitor System
(TPMS) operates on a radio
frequency and complies with
Part 15 of the FCC Rules.
Operation is subject to the
following two conditions:
1. This device may not cause
harmful interference.
2. This device must accept any
interference received, including
interference that may cause
undesired operation.The TPMS operates on a radio
frequency and complies with
RSS-210 of Industry and Science
Canada. Operation is subject to the
following two conditions:
1. This device may not cause
interference.
2. This device must accept any
interference received, including
interference that may cause
undesired operation of the device.
Changes or modications to this
system by other than an authorized
service facility could void
authorization to use this equipment.
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Tire Pressure Monitor
Operation
This vehicle may have a Tire
Pressure Monitor System (TPMS).
The TPMS is designed to warn
the driver when a low tire pressure
condition exists. TPMS sensors
are mounted onto each tire and
wheel assembly, excluding the
spare tire. The TPMS sensors
monitor the air pressure in the
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 illuminates
the low tire pressure warning
light located in the instrument
panel cluster.The low tire pressure warning light
comes on at each ignition cycle
until the tires are inated to
the correct ination pressure.
The low tire pressure warning light
may come on in cool weather
when the vehicle is rst started, and
then turn off as you start to drive.
This could be an early indicator that
the air pressure in the tire(s) are
getting low and need to be inated
to the proper pressure.
You must begin driving before the
TPMS system is operational.
TPMS sensors need to be installed
onto the full-size tire and wheel
assemblies, and the tires adjusted
to the manufacturers’ recommended
tire pressure amount.
A Tire and Load Information label is
attached to the vehicle, and
shows the size of the vehicle’s
original equipment tires and
the correct ination pressure for the
tires when they are cold. See
Loading the Vehicle on page 8-30,
for an example of the Tire andLoad Information label and its
location on the vehicle. Also see
Inflation - Tire Pressure on
page 9-47.
The vehicle’s TPMS can warn you
about a low tire pressure condition
but it does not replace normal
tire maintenance. SeeTire
Inspection and Rotation on
page 9-52andTires on page 9-40.
Notice:Liquid tire sealants
could damage the Tire Pressure
Monitor System (TPMS) sensors.
Sensor damage caused by
using a tire sealant is not covered
by your warranty. Do not use
liquid tire sealants.
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 are automatically learned by
the TPMS. This occurs within a
few moments of driving the vehicle
over 19 mph (31 km/h).
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TPMS Malfunction Light
The TPMS will not function properly
if one or more of the TPMS
sensors are missing or inoperable.
When the system detects a
malfunction, the low tire warning
light ashes for about one minute
and then stays on for the remainder
of the ignition cycle. Some of the
conditions that can cause the
malfunction light to come on are:
One of the road tires has been
replaced with the spare tire. The
spare tire does not have a TPMS
sensor. The TPMS malfunction
light and DIC message should go
off once you re-install the road tire
containing the TPMS sensor.
One or more TPMS sensors are
missing or damaged. The TPMS
malfunction light should go off
after the TPMS sensors are
installed and the vehicle is
driven for a few moments over
19 mph (31 km/h). See your
dealer/retailer for service.
Replacement tires or wheels do
not match the vehicle’s original
equipment tires or wheels. Tires
and wheels other than those
recommended for the vehicle
could prevent the TPMS from
functioning properly. SeeBuying
New Tires on page 9-54.
Operating electronic devices or
being near facilities using radio
wave frequencies similar to the
TPMS could cause the TPMS
sensors to malfunction.
If the TPMS is not functioning it
cannot detect or signal a low tire
condition. See your dealer/retailer for
service if the TPMS malfunction light
comes on and stays on.
Tire Inspection and
Rotation
Inspect tires regularly for signs of
wear or damage. Also inspect the
spare tire. For more information
on tire inspection, seeWhen It Is
Time for New Tires on page 9-54.
Rotating vehicle tires helps them
to wear evenly and keeps the
vehicle performing like it
did when tires were new.
Rotate the tires and check
wheel alignment approximately
every 5,000 to 8,000 miles
(8 000 to 13 000 km) or when
unusual tire wear is noted.
See “Scheduled Maintenance”
in the Index of the “Limited
Warranty, Maintenance
and Owner Assistance
Information” manual for more
information. Also check the
wheels for damage, seeWheel
Replacement on page 9-59
for more information.
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Use this pattern when rotating
the vehicle tires. Do not include
the compact spare tire in the
tire rotation.
{CAUTION
Rust or dirt on a wheel, or on
the parts to which it is
fastened, can make wheel
bolts become loose after time.
(Continued)
CAUTION (Continued)
The wheel could come off and
cause a crash. When you
change a wheel, remove any
rust or dirt from places where
the wheel attaches to the
vehicle using a scraper or
wire brush.
Installing wheels with a good
metal-to-metal contact at
the mounting surfaces is
necessary to prevent wheel
bolts from becoming loose.
To prevent corrosion or
rust build-up, lightly coat the
wheel hub center and the
cone-shaped surface of each
wheel bolt with wheel bearing
grease, after a wheel change.SeeChanging a Flat Tire on
page 9-61for information
on installing the tire and wheel
assembly. Also see “Wheel
Bolt Torque” underCapacities
and Specifications on page 10-2.
Adjust the front and rear
tires to the recommended
cold tire ination pressure
shown on the Tire and
Loading Information label.
SeeInflation - Tire Pressure
on page 9-47andLoading the
Vehicle on page 8-30.
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