2008 CADILLAC XLR wheel

TPMS Malfunction Light and Message
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. A DIC warning
message is also displayed. The low tire warning light
and DIC warning message come on at each ignition
cycle until the problem is corrected. Some of the
conditions that can cause the malfunction light and
DIC message to come on are:
The TPMS sensor matching process was not done
or not completed successfully. The DIC message
should go off after successfully completing the
sensor matching process.
One or more TPMS sensors are missing or
damaged. Under these conditions the TPMS
malfunction light (low tire warning light) comes on,
and at the same time the DIC message is
displayed. The DIC message and TPMS malfunction
light should go off once the TPMS sensors are
installed and the sensor matching process is
performed successfully.
Replacement tires or wheels do not match your
vehicle’s original equipment tires or wheels.
Tires and wheels other than those recommended
for your vehicle could prevent the TPMS from
functioning properly. SeeBuying New Tires on
page 6-67.
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 and DIC message
comes on and stays on.
TPMS Sensor Matching Process
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
dealer/retailer for service.
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Tire Inspection and Rotation
We recommend that you regularly inspect your
vehicle’s tires for signs of wear or damage.
SeeWhen It Is Time for New Tires on page 6-66
for additional information.
If your vehicle has P235/50R18 size tires they
should be rotated any time you notice unusual
wear. Rotate the 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 6-66andWheel Replacement
on page 6-70.
When rotating P235/50R18 size tires, always use
the correct rotation pattern shown here.After the tires have been rotated, adjust the front
and rear ination pressures as shown on the Tire
and Loading Information label, seeInflation - Tire
Pressure on page 6-60andLoading Your Vehicle
on page 5-22. Vehicles that have the Tire Pressure
Monitor System (TPMS) need the TPMS sensors
reset after a tire rotation is performed. A special tool
is needed to reset the sensor identication codes.
See your dealer/retailer for service. Make certain
that all wheel nuts are properly tightened. See
Wheel Replacement on page 6-70and “Wheel Nut
Torque” underCapacities and Specifications on
page 6-97
.
{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 a crash. 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.
6-65

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 near the tire
size. 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 6-54, for additional information.
GM recommends replacing tires in sets of four. This is
because uniform tread depth on all tires will help
keep your vehicle performing most like it did when the
tires were new. Replacing less than a full set of tires can
affect the braking and handling performance of your
vehicle. SeeTire Inspection and Rotation on page 6-65.Winter tires with the same speed rating as your original
equipment tires may not be available for H, V, W, Y
and ZR speed rated tires. If you choose snow tires with
a lower speed rating, never exceed the tire’s maximum
speed capability.
{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), brands or types, may also cause
damage to your vehicle. Be sure to use the
correct size, brand, and type tires on all
four wheels.
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{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.
Vehicles that have a tire pressure monitoring system
could give an inaccurate low-pressure warning if
non-TPC Spec rated tires are installed on it. Non-TPC
Spec rated tires may give a low-pressure warning that is
higher or lower than the proper warning level you
would get with TPC Spec rated tires. SeeTire Pressure
Monitor System on page 6-61.
Your vehicle’s original equipment tires are listed on the
Tire and Loading Information label. SeeLoading
Your Vehicle on page 5-22, 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.
SeeBuying New Tires on page 6-67andAccessories
and Modifications on page 6-3for additional information.
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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
specied 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 inated and
not overloaded. Excessive speed, underination,
or excessive loading, either separately or in
combination, can cause heat buildup and possible
tire failure.
Wheel Alignment and Tire Balance
The tires and wheels on your vehicle were aligned
and balanced carefully at the factory to give you the
longest tire life and best overall performance.
Adjustments to wheel alignment and tire balancing will
not be necessary on a regular basis. However, if
you notice unusual tire wear or your vehicle pulling to
one side or the other, the alignment might need to
be checked. If you notice your vehicle vibrating when
driving on a smooth road, the tires and wheels
might need to be rebalanced. See your dealer/retailer
for proper diagnosis.
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/retailer if any of these conditions exist.
Your dealer/retailer will know the kind of wheel you need.
Each new wheel should have the same load-carrying
capacity, diameter, width, offset, and be mounted
the same way as the one it replaces.
6-70

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 clearance to
the body and chassis.
{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 a crash. 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.
{CAUTION:
Never use oil or grease on studs or the threads
of the wheel nuts. If you do, the wheel nuts
might come loose and the wheel could fall off,
causing a crash.
6-71

Tightening Wheel Lug Nuts
{CAUTION:
Incorrect wheel nuts or improperly tightened
wheel nuts can cause the wheel to become
loose and even come off. This could lead to a
crash. Be sure to use the correct wheel nuts.
If you have to replace them, be sure to get new
GM original equipment wheel nuts.Notice:Improperly tightened wheel nuts can lead
to brake pulsation and rotor damage. To avoid
expensive brake repairs, evenly tighten the wheel
nuts in the proper sequence and to the proper
torque specication.
Tighten the wheel lug nuts
rmly in a crisscross
sequence as shown.
6-72

Used Replacement Wheels
{CAUTION:
Putting a used wheel on your vehicle is
dangerous. You cannot know how it has been
used or how far it has been driven. It could fail
suddenly and cause a crash. If you have to
replace a wheel, use a new GM original
equipment wheel.
Tire Chains
{CAUTION:
Do not use tire chains. There is not enough
clearance. Tire chains used on a vehicle
without the proper amount of clearance can
cause damage to the brakes, suspension, or
other vehicle parts. The area damaged by the
tire chains could cause you to lose control of
your vehicle and you or others may be injured
in a crash. Use another type of traction device
only if its manufacturer recommends it for use
on your vehicle and tire size combination and
road conditions. Follow that manufacturer’s
instructions. To help avoid damage to your
vehicle, drive slowly, re-adjust or remove the
device if it is contacting your vehicle, and do
not spin your wheels. If you do nd traction
devices that will t, install them on the
rear tires.
6-73