2007 CADILLAC STS service

(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.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/transaxle, 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.
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If a tire goes at, you will not need to stop on the
side of the road to change the tire. You can
just keep on driving. The vehicle’s run-at tires
can operate effectively with no air pressure for up
to 50 miles (80 km) at speeds up to 55 mph
(90 km/h). The shorter the distance you drive and
the slower the speed, the greater the chance
that the tire will not have to be replaced. When a
tire is lled with air, it provides a cushion
between the road and the wheel. Because you will
not have this cushion when driving on a deated
run-at tire, try to avoid potholes that could
damage your wheel and require replacement of it.
Some road hazards can damage a tire beyond
repair. This damage could occur even before you
have driven on the tire in a deated condition.
When a tire has been damaged, or if you have
driven any distance on a deated run-at tire, check
with an authorized run-at tire service center, as
soon as possible, to determine whether the tire can
be repaired or should be replaced. To maintain your
vehicle’s run-at feature, all replacement tires must
be self-supporting tires. To locate the nearest GM
or authorized run-at servicing facility, call
Roadside Service. SeeRoadside Service on
page 531for details.
{CAUTION:
Run-at tires are constructed differently
than other tires and could explode during
improper service. You or others could be
injured or killed if you attempt to repair,
replace, dismount, or mount a run-at tire.
Let only an authorized run-at service
center repair, replace, dismount, and
mount run-at tires.
The valve stems on your vehicle’s run-at tires
have sensors that are part of the Tire Pressure
Monitor System (TPMS). These sensors contain
batteries which are designed to last for 10 years
under normal driving conditions. See your GM
dealer, if the TPMS sensors or a wheel ever need
replacement.
Notice:Using liquid sealants can damage the
tire valves and tire pressure monitor sensors in
your vehicle’s run-at tires. This damage would
not be covered by warranty. Do not use liquid
sealants in your vehicle’s run-at tires.
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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 your vehicle’s tires,
the identication codes will 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
GM 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. If
using this method to match TPMS sensors, the
complete procedure outlined below must be
performed within 15 minutes of the vehicle being
stationary.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/wheel positions, the matching process
stops and you will need to start over.
The TPM matching process is outlined below:
1. Set the parking brake.
2. Press the push-button ignition switch to Acc.
(Off/Accessory).
3. Using the Keyless Access transmitter, lock
and unlock the vehicle’s doors.
4. Press the lock and unlock buttons, at the
same time, on the Keyless Access
transmitter. A single horn chirp will sound,
indicating that the TPMS is ready, and
the sensor matching process can begin.
5. Start with the driver’s side front tire.
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6. Remove the valve cap from the valve stem.
Activate the TPMS sensor by increasing
or decreasing the tire’s air pressure for
ve 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 this tire position. To
decrease the tire’s air-pressure use the pointed
end of the valve cap, a pencil-style air pressure
gauge, or a key.
7. Proceed to the passenger’s side front tire, and
repeat the procedure in Step 6.
8. Proceed to the passenger’s side rear tire, and
repeat the procedure in Step 6.
9. Proceed to the driver’s side rear tire, and
repeat the procedure in Step 6.
10. After hearing the conrming single horn chirp
for the driver’s side rear tire, a double horn
chirp will sound to signal the tire matching
mode is no longer active. Press the
push-button ignition switch to Acc.11. Set all four tires to the recommended air
pressure level as indicated on the tire and
loading information label.
12. Put the valve caps back on the valve stems.
The spare tire does not have a TPMS sensor.
If you replace one of the road tires with the spare,
the SERVICE TIRE MONITOR message will be
displayed on the DIC screen. This message should
go off once you re-install the road tire containing
the TPM sensor.
Federal Communications Commission
(FCC) and Industry and Science Canada
This device 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.
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This device complies with RSS-210 of Industry
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.
Tire Inspection and Rotation
Tire rotation is not recommended if your vehicle
has the following performance tire combinations:
P235/50R17 size tires on the front wheels
and P255/45R17 size tires on the rear
wheels.
P235/50R18 size tires on the front wheels and
P255/45R18 size tires on the rear wheels.
P255/45R18 size tires on the front wheels and
P275/40R19 size tires on the rear wheels.Different tire sizes should not be rotated front to
rear. Each tire and wheel should only be used
in the original front or rear position it is in.
Tire rotation is recommended if your vehicle is
equipped with P235/50R17 size tires on all
four wheel positions or 255/45ZR18 size tires on
all four wheel positions. These 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.
SeeWhen It Is Time for New Tires on page 440
andWheel Replacement on page 445for
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 505.
438

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 (NHTSA), 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 (UTQG)
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 specied 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 signicantly 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 specied 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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Lifting From the Front
The front lifting points can be accessed from
either side of your vehicle, behind the front tires.
1. Locate the front lifting points using the
diagram above. The front lifting location
is about 15 inches (37 cm) from the rear edge
of the front wheel well.
2. Be sure to place a block or pad between the
jack and the vehicle.
3. Lift the vehicle with the jack, making sure the
jack is centered on the front lifting point.
Lifting From the Rear
The rear lifting points can be accessed from either
side of your vehicle, in front of the rear tires.
1. Locate the rear lifting points using the
diagram above. The rear lifting location
is about 7 inches (17 cm) from the front edge
of the rear wheel well.
2. Be sure to place a block or pad between the
jack and the vehicle.
3. Lift the vehicle with the jack, making sure the
jack is centered on the rear lifting point.
SeeDoing Your Own Service Work on page 364.
450

Run-Flat Tires (STS-V)
If your vehicle has run-at tires, there is no spare
tire and no tire changing equipment. Run-at
tires can operate effectively with no air pressure
for a limited distance and speed. These tires
perform so well without any air pressure that a Tire
Pressure Monitor (TPM) is used to alert you
when there is a low tire condition.
{CAUTION:
When the low tire warning light is
displayed on the instrument panel cluster,
your vehicle’s handling capabilities will be
reduced during severe maneuvers. If you
drive too fast, you could lose control of
your vehicle. You or others could be
injured. Do not drive over 55 mph
(90 km/h) when the low tire warning light
is displayed. Drive cautiously and check
your tire pressures as soon as you can.SeeRun-Flat Tires (STS-V) on page 429andTire
Pressure Monitor System on page 433, for
additional information.
{CAUTION:
Special tools and procedures are required
to service a run-at tire. If these special
tools and procedures are not used you or
others could be injured and your vehicle
could be damaged. Always be sure the
proper tools and procedures, as described
in the service manual, are used.
To order a service manual seeService
Publications Ordering Information on page 543.
Tire Inator Kit
Your vehicle has a tire inator kit. There is no jack
or spare tire. The kit uses a liquid tire sealant
and air at the same time to seal small punctures
in the tread area of the tire. Be sure to read
and follow all of the tire inator kit instructions.
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