2008 CADILLAC CTS Owners Manual

A DIC warning message to check the pressure in a
specic tire is also shown on the DIC display screen.
The low tire pressure warning light and the DIC warning
message come 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.
The Tire and Loading Information label, attached to
your vehicle, shows the size of your vehicle’s original
equipment tires and the correct ination pressure for the
tires when they are cold. SeeLoading the Vehicle on
page 4-22, for an example of the Tire and Loading
Information label and its location on your vehicle.
Also seeInflation - Tire Pressure on page 5-66.Your 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 5-74andTires on page 5-58.
Notice:Using non-approved tire sealants could
damage the Tire Pressure Monitor System (TPMS)
sensors. TPMS sensor damage caused by using
an incorrect tire sealant is not covered by the
vehicle warranty. Always use the GM approved
tire sealant available through your dealer/retailer.
Your vehicle, when new, may have included a
factory-installed Tire Sealant and Compressor Kit.
This kit uses a GM approved liquid tire sealant. See
Tire Sealant and Compressor Kit (With Sealant Selector
Switch) on page 5-84orTire Sealant and Compressor
Kit (Without Sealant Selector Switch) on page 5-93.
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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:
One of the road tires has been replaced with the
spare tire. The spare tire does not have a TPMS
sensor. The DIC message should go off once you
re-install the road tire containing the TPMS sensor.
The TPMS sensor matching process was not
done or not completed successfully after rotating
the vehicle’s tires. The DIC message should go off
after successfully completing the sensor matching
process. See “TPMS Sensor Matching Process”
later in this section.
One or more TPMS sensors are missing or
damaged. The DIC message and the TPMS
malfunction light should go off when the TPMS
sensors are installed and the sensor matching
process is performed successfully. See your
dealer/retailer for service.
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 5-76.
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.
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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
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.
The TPMS sensors can also be matched to each
tire/wheel position by increasing or decreasing the tire’s
air pressure. If increasing the tire’s air pressure, do not
exceed the maximum ination pressure indicated on the
tire’s sidewall. To decrease the tire’s air-pressure use the
pointed end of the valve cap, a pencil-style air pressure
gage, or a key.
You have two minutes to match the rst tire/wheel
position, and ve minutes overall, to match all four
tire/wheel positions. If it takes longer than two minutes,
to match the rst tire and wheel, or more than
ve minutes to match all four tire and wheel positions,
the matching process stops and you need to start over.The TPMS matching process is outlined below:
1. Set the parking brake.
2. Turn the ignition switch to ON/RUN with the
engine off.
3. Press the Remote Keyless Entry (RKE) transmitter’s
lock and unlock buttons at the same time for
approximately ve seconds. The horn sounds twice
to signal the receiver is in relearn mode and Tire
Learning Active message displays on the DIC
screen.
4. Start with the driver side front tire.
5. Remove the valve cap from the valve stem.
Activate the TPMS sensor by increasing or
decreasing the tire’s air pressure for 10 seconds,
or until a horn chirp sounds. The horn chirp, which
can take up to 30 seconds to sound, conrms
that the TPMS sensor identication code has
been matched to this tire position.
6. Proceed to the passenger side front tire, and repeat
the procedure in Step 5.
7. Proceed to the passenger side rear tire, and repeat
the procedure in Step 5.
8. Proceed to the driver side rear tire, and repeat the
procedure in Step 5.
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9. After hearing the conrming horn chirp, for the
driver side rear tire, the horn sounds two more
times to signal the tire learning mode is no longer
active. Turn the ignition switch to LOCK/OFF.
10. Set all four tires to the recommended air pressure
level as indicated on the tire and loading information
label.
11. Put the valve caps back on the valve stems.
Tire Inspection and Rotation
We recommend that you regularly inspect your
vehicle’s tires, including the spare tire, for signs
of wear or damage. SeeWhen It Is Time for New
Tires on page 5-75for more information.
Tires should be rotated every 5,000 to 8,000 miles
(8 000 to 13 000 km). SeeScheduled Maintenance
on page 6-4.
The purpose of a regular tire rotation is to achieve
a uniform wear for all tires on the vehicle. This will
ensure that your vehicle continues to perform most
like it did when the tires were new.
If your vehicle has 235/50ZR18 size tires, GM
recommends rotating these tires at 3,000 mile
(4 800 km) intervals. These tires are optimized fordry traction and handling performance. Tread life
may be 15,000 miles (24 140 km) or less for these
tires, depending on how and where you drive.
Any time you notice unusual wear, rotate your
vehicle’s 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 5-75andWheel Replacement on page 5-80
for more information.
When rotating your vehicle’s tires, always use the
correct rotation pattern shown here.
If your vehicle has a compact spare tire, do not
include it in the tire rotation.
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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 5-66andLoading the Vehicle on
page 4-22.
Reset the Tire Pressure Monitor System. SeeTire
Pressure Monitor Operation on page 5-70.
Make certain that all wheel nuts are properly
tightened. See “Wheel Nut Torque” under
Capacities and Specifications on page 5-129.
{CAUTION:
Rust or dirt on a wheel, or on the parts to
which it is fastened, can make wheel nuts
become loose after 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 needed, to get all the rust or
dirt off. SeeChanging a Flat Tire on
page 5-102.
When It Is Time for New Tires
Various factors, such as maintenance, temperatures,
driving speeds, vehicle loading, and road conditions
inuence when you need new tires.
One way to tell when it
is 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.
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You need new tires 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
cannot be repaired well because of the size or
location of the damage.
The rubber in tires degrades over time, even if they are
not being used. This is also true for the spare tire, if your
vehicle has one. Multiple conditions affect how fast this
aging takes place, including temperatures, loading
conditions, and ination pressure maintenance. With
proper care and maintenance tires will typically wear out
before they degrade due to age. If you are unsure about
the need to replace your tires as they get older, consult
the tire manufacturer for more information.
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 5-60
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 5-74for
information on proper tire rotation.
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Winter tires with the same speed rating as your vehicle’s
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, 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,
brands, or types may also cause damage
to your vehicle. Be sure to use the correct
size, brand, and type of tires on all wheels.
It is all right to drive with your compact
spare temporarily, as it was developed for
use on your vehicle. SeeCompact Spare
Tire on page 5-111.
{CAUTION:
If you use bias-ply tires on the 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 the 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 your vehicle.
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 5-69.
Your vehicle’s original equipment tires are listed on
the Tire and Loading Information Label. SeeLoading the
Vehicle on page 4-22, for more information about the
Tire and Loading Information Label and its location
on your vehicle.
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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, antilock 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 5-76andAccessories
and Modifications on page 5-4for additional information.
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.
5-78