2008 CHEVROLET COBALT Owners Manual

Tire Pressure Monitor Operation
The Tire Pressure Monitor System (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 and wheel
assembly. The TPMS sensors monitor the air pressure
in the vehicle’s tires and transmits the tire pressure
readings to a receiver located in the vehicle.
When a low tire pressure
condition is detected,
the TPMS turns on the
low tire pressure warning
light located on the
instrument panel cluster.
At the same time a message to check the pressure
in a specic tire appears on the Driver Information
Center (DIC) display. The low tire pressure warning
light and the DIC warning message come on at
each ignition cycle until the tires are inated to thecorrect ination pressure. Using the DIC, tire pressure
levels can be viewed by the driver. For additional
information and details about the DIC operation and
displays seeDIC Operation and Displays on page 3-40
andDIC Warnings and Messages on page 3-43.
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.
A Tire and Loading Information label shows the size of
your vehicle’s original equipment tires and the correct
ination pressure for your vehicle’s tires when they are
cold. SeeLoading Your Vehicle on page 4-27, for an
example of the Tire and Loading Information label and
its location on your vehicle. Also seeInflation - Tire
Pressure on page 5-56.
Your vehicle’s TPMS system can warn you about a low
tire pressure condition but it does not replace normal
tire maintenance. SeeTire Inspection and Rotation
on page 5-63andTires on page 5-49.
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.
5-59

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 TPMS malfunction light and
DIC message should go off once you re-install
the road tire containing the TPMS sensor.
The TPMS sensor matching process was started
but not completed or not completed successfully
after rotating the vehicle’s tires. The DIC message
and TPMS malfunction light should go off once
the TPMS sensor matching process is performed
successfully. 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 5-66.
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 the vehicle’s tires, the identication codes
need to be matched to the new tire/wheel location.
The sensors are matched, to the tire/wheel locations,
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. When increasing the tire’s 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 each tire and wheel
position. If it takes longer than two minutes to match
any tire and wheel position, the matching process
stops and you need to start over.
TPMS Matching Process for Vehicles
with Remote Keyless Entry (RKE)
1. Set the parking brake.
2. Turn the ignition switch to ON/RUN with the
engine off.
3. Press and hold the Remote Keyless Entry (RKE)
transmitter’s LOCK and UNLOCK buttons, at the
same time, for about ve seconds to start the TPMS
learn mode. The horn sounds twice indicating the
TPMS receiver is ready and in learn mode.
4. Start with the driver side front tire. The driver side
front turn signal also comes on to indicate that
corner’s sensor is ready to be learned.
5. Remove the valve cap from the tire’s valve stem.
Activate the TPMS sensor by increasing or
decreasing the tire’s air pressure for about
eight seconds. The horn chirp, can take up to
30 seconds to sound. It chirps one time and then all
the turn signals ash one time to conrm the
sensor identication code has been matched to the
tire/wheel position.
6. The passenger side front turn signal comes on to
indicate that corner sensor is ready to be learned.
Proceed to the passenger side front tire and
repeat the procedure in Step 5.
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7. The passenger side rear turn signal comes on to
indicate that corner sensor is ready to be learned.
Proceed to the passenger side rear tire and
repeat the procedure in Step 5.
8. The driver side rear turn signal comes on to
indicate that corner sensor is ready to be learned.
Proceed to the driver side rear tire, and repeat
the procedure in Step 5.
9. After hearing the single horn chirp for the driver
side rear tire, two additional horn chirps sound
to indicate the tire learning process is done.
Turn the ignition switch to LOCK/OFF.
If no tires are learned after entering the TPMS
learn mode, or if communication with the receiver
stops, or if the time limit has expired, turn the
ignition switch to LOCK/OFF and start over
beginning with Step 2.
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.TPMS Matching Process for Vehicles
without Remote Keyless Entry (RKE)
1. Set the parking brake.
2. Turn the ignition switch to ON/RUN with the
engine off.
3. Using the Driver Information Center (DIC), press
the INFO and Set/Reset buttons at the same time
for about one second. Then press and release
the INFO button until the TIRE LEARN? message
displays.
4. Press and hold the Set/Reset DIC button for
approximately three seconds to start the TPMS
learn mode. The horn sounds twice to indicate the
TPMS receiver is ready and the TIRE LEARN
ON message displays. The driver side front turn
signal also comes on to indicate that corner sensor
is ready to be learned.
5. Start with the driver side front tire.
6. Remove the valve cap from the tire’s valve stem.
Activate the TPMS sensor by increasing or
decreasing the tire’s air pressure for about
eight seconds. The horn chirp, can take up to
30 seconds to sound. It chirps one time and then all
the turn signals ash one time to conrm the sensor
identication code has been matched to the tire/
wheel position.
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7. The passenger side front turn signal comes on to
indicate that corner sensor is ready to be learned.
Proceed to the passenger side front tire and
repeat the procedure in Step 6.
8. The passenger side rear turn signal comes on to
indicate that corner sensor is ready to be learned.
Proceed to the passenger side rear tire and
repeat the procedure in Step 6.
9. The driver side rear turn signal comes on to
indicate that corner sensor is ready to be learned.
Proceed to the driver side rear tire, and repeat
the procedure in Step 6.
10. After hearing the single horn chirp for the driver
side rear tire, two additional horn chirps sound to
indicate the tire learning process is done. The
LEARN COMPLETE message displays if all
four tire positions are learned. Turn the ignition
switch to LOCK/OFF.
If no tires are learned after entering the TPMS
learn mode, or if communication with the receiver
stops, or if the time limit has expired, the TIRE
LEARN? message displays on the DIC. Turn
the ignition switch to LOCK/OFF and start over
beginning with Step 2.11. 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.
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 5-65for 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.
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Any time you notice unusual wear, rotate the tires
as soon as possible and check wheel alignment.
Also check for damaged tires or wheels. See
When It Is Time for New Tires on page 5-65and
Wheel Replacement on page 5-70.
When rotating the vehicle’s tires, always use
the correct rotation pattern shown here.
Do not include the compact spare tire in the
tire rotation.
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 5-56
andLoading Your Vehicle on page 4-27.Reset the Tire Pressure Monitor System. See
Tire Pressure Monitor Operation on page 5-59.
Make certain that all wheel nuts are properly
tightened. See “Wheel Nut Torque” under
Capacities and Specifications on page 5-112.
{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 5-74.
5-64

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.
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.
5-65

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 5-50for 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 5-63
for information on proper tire rotation.
{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 5-94.
5-66