2009 JEEP LIBERTY tire pressure

WARNING! (Continued)
•Unequal tire pressures can cause steering prob-
lems. You could lose control of your vehicle.
• Over-inflated or under-inflated tires can affect
vehicle handling and can fail suddenly, resulting in
loss of vehicle control.
• Unequal tire pressures from one side of the vehicle
to the other can cause the vehicle to drift to the right
or left.
• Always drive with each tire inflated to the recom-
mended cold tire inflation pressure.
Economy
Improper inflation pressures can cause uneven wear
patterns to develop across the tire tread. These abnormal
wear patterns will reduce tread life resulting in a need for earlier tire replacement. Under-inflation also increases
tire rolling resistance and results in higher fuel
consumption.
Ride Comfort and Vehicle Stability
Proper tire inflation contributes to a comfortable ride.
Over-inflation produces a jarring and uncomfortable
ride. Both under-inflation and over-inflation affect the
stability of the vehicle and can produce a feeling of
sluggish response or over responsiveness in the steering.
Unequal tire pressures can cause erratic and unpredict-
able steering response.
Unequal tire pressure from side to side may cause the
vehicle to drift left or right.
Tire Inflation Pressures
The proper cold tire inflation pressure is listed on the
driver’s side “B” Pillar.
STARTING AND OPERATING 347
5

The pressure should be checked and adjusted, as well as
inspected for signs of tire wear or visible damage, at least
once a month. Use a good quality pocket-type gauge to
check tire pressure. Do not make a visual judgement
when determining proper inflation. Radial tires may look
properly inflated even when they are under-inflated.
CAUTION!
After inspecting or adjusting the tire pressure, al-
ways reinstall the valve stem cap (if equipped). This
will prevent moisture and dirt from entering the
valve stem, which could damage it.
Inflation pressures specified on the placard are always
cold tire inflation pressure. Cold tire inflation pressure is
defined as the tire pressure after the vehicle has not been
driven for at least three hours, or driven less than 1 mile (1.6 km) after a three-hour period. The cold tire inflation
pressure must not exceed the maximum inflation pres-
sure molded into the tire sidewall.
Check tire pressures more often if subject to a wide range
of outdoor temperatures, as tire pressures vary with
temperature changes.
Tire pressures change by approximately 1 psi (7 kPa) per
12°F (7°C) of air temperature change. Keep this in mind
when checking tire pressure inside a garage, especially in
the winter.
Example: If garage temperature = 68°F (20°C) and the
outside temperature = 32°F (0°C) then the cold tire
inflation pressure should be increased by 3 psi (21 kPa),
which equals 1 psi (7 kPa) for every 12°F (7°C) for this
outside temperature condition.
348 STARTING AND OPERATING

Tire pressure may increase from 2 to 6 psi (13 to 40 kPa)
during operation. DO NOT reduce this normal pressure
build-up, or your tire pressure will be too low.
Tire Pressures For High Speed Operation
The manufacturer advocates driving at safe speeds
within posted speed limits. Where speed limits or condi-
tions are such that the vehicle can be driven at high
speeds, maintaining correct tire inflation pressure is very
important. Increased tire pressure and reduced vehicle
loading may be required for high-speed vehicle opera-
tion. Refer to original equipment or an authorized tire
dealer for recommended safe operating speeds, loading
and cold tire inflation pressures.
WARNING!
High speed driving with your vehicle at or above
maximum load is dangerous. The added strain on
your tires could cause them to fail. You could have a
serious accident. Do not drive a vehicle loaded to the
maximum capacity at continuous speeds above
75 mph (120 km/h).
Radial-Ply Tires
WARNING!
Combining radial ply tires with other types of tires
on your vehicle will cause your vehicle to handle
poorly. The instability could cause an accident. Al-
ways use radial tires in sets of four. Never combine
them with other types of tires.
STARTING AND OPERATING 349
5

These indicators are molded into the bottom of the tread
grooves. They will appear as bands when the tread depth
becomes 1/16 in (2 mm). When the indicators appear in
two or more adjacent grooves, the tire should be replaced.
Life Of Tire
The service life of a tire is dependent upon various
factors including but not limited to:
•Driving style
•Tire pressure
•Distance driven
WARNING!
Tires and the spare tire should be replaced after six
years, regardless of the remaining tread. Failure to
follow this warning can result in sudden tire failure.
You could lose control and have an accident resulting
in serious injury or death.Keep dismounted tires in a cool, dry place with as little
exposure to light as possible. Protect tires from contact
with oil, grease, and gasoline.
Replacement Tires
The tires on your new vehicle provide a balance of many
characteristics. They should be inspected regularly for
wear and correct cold tire inflation pressure. The manu-
facturer strongly recommends that you use tires equiva-
lent to the originals in size, quality and performance
when replacement is needed. (Refer to the paragraph on
“Tread Wear Indicators”). Refer to the “Tire and Loading
Information” placard for the size designation of your
tires. The service description and load identification will
be found on the original equipment tire. Failure to use
equivalent replacement tires may adversely affect the
safety, handling, and ride of your vehicle. We recommend
that you contact your original equipment or an autho-
rized tire dealer with any questions you may have on tire
specifications or capability.
352 STARTING AND OPERATING

Refer to the “Maintenance Schedule” in Section 8 of this
manual for the proper maintenance intervals. Remember,
more frequent rotation is permissible if desired. Also,
correct for anything causing rapid or unusual wear prior
to performing the tire rotation.
TIRE PRESSURE MONITOR SYSTEM (TPMS)
The Tire Pressure Monitor System (TPMS) will warn the
driver of a low tire pressure based on the vehicle recom-
mended cold placard pressure.
The tire pressure will vary with temperature by about
1 psi (6.9 kPa) for every 12°F (6.5°C). This means that
when the outside temperature decreases, the tire pressure
will decrease. Tire pressure should always be set based
on cold inflation tire pressure. This is defined as the tire
pressure after the vehicle has not been driven for at least
three hours, or driven less than 1 mile (1 km) after a three
hour period. The cold tire inflation pressure must not
exceed the maximum inflation pressure molded into thetire sidewall. Refer to the “Tires – General Information”
in this section for information on how to properly inflate
the vehicle’s tires. The tire pressure will also increase as
the vehicle is driven. This is normal and there should be
no adjustment for this increased pressure.
The TPMS will warn the driver of a low tire pressure if
the tire pressure falls below the low-pressure warning
limit for any reason, including low temperature effects
and natural pressure loss through the tire.
The TPMS will continue to warn the driver of low tire
pressure as long as the condition exists, and will not turn
off until the tire pressure is at or above the recommended
cold placard pressure. Once the low tire pressure warn-
ing (Tire Pressure Monitoring Telltale Light) illuminates,
you must increase the tire pressure to the recommended
cold placard pressure in order for the Tire Pressure
Monitoring Telltale Light to turn off. The system will
automatically update and the Tire Pressure Monitoring
356 STARTING AND OPERATING

Telltale Light will turn off once the system receives the
updated tire pressures. The vehicle may need to be
driven for up to 20 minutes above 15 mph (25 km/h) in
order for the TPMS to receive this information.
For example, your vehicle may have a recommended
cold (parked for more than three hours) placard pressure
of 33 psi (227 kPa). If the ambient temperature is 68°F
(20°C) and the measured tire pressure is 28 psi (193 kPa),
a temperature drop to 20°F (-7°C) will decrease the tire
pressure to approximately 24 psi (165 kPa). This tire
pressure is low enough to turn ON the Tire Pressure
Monitoring Telltale Light. Driving the vehicle may cause
the tire pressure to rise to approximately 28 psi (193 kPa),
but the Tire Pressure Monitoring Telltale Light will still
be on. In this situation, the Tire Pressure Monitoring
Telltale Light will turn off only after the tires are inflated
to the vehicle’s recommended cold placard pressure
value.CAUTION!
•The TPMS has been optimized for the original
equipment tires and wheels. TPMS pressures and
warning have been established for the tire size
equipped on your vehicle. Undesirable system
operation or sensor damage may result when us-
ing replacement equipment that is not of the same
size, type, and/or style. Aftermarket wheels can
cause sensor damage. Do not use aftermarket tire
sealants or balance beads if your vehicle is
equipped with a TPMS, as damage to the sensors
may result.
•After inspecting or adjusting the tire pressure,
always reinstall the valve stem cap. This will
prevent moisture and dirt from entering the valve
stem, which could damage the Tire Pressure Moni-
toring Sensor.
STARTING AND OPERATING 357
5

NOTE:
•The TPMS is not intended to replace normal tire care
and maintenance, or to provide warning of a tire
failure or condition.
•The TPMS should not be used as a tire pressure gauge
while adjusting your tire pressure.
•Driving on a significantly under-inflated tire causes
the tire to overheat and can lead to tire failure.
Under-inflation also reduces fuel efficiency and tire
tread life, and may affect the vehicle’s handling and
stopping ability.
•The TPMS is not a substitute for proper tire mainte-
nance, and it is the driver ’s responsibility to maintain
correct tire pressure using an accurate tire pressure
gauge, even if under-inflation has not reached the
level to trigger illumination of the Tire Pressure Moni-
toring Telltale Light.
•Seasonal temperature changes will affect tire pressure,
and the TPMS will monitor the actual tire pressure in
the tire.
Base System
The Tire Pressure Monitor System (TPMS) uses wireless
technology with wheel rim mounted electronic sensors to
monitor tire pressure levels. Sensors, mounted to each
wheel as part of the valve stem, transmit tire pressure
readings to the receiver module.
NOTE:It is particularly important for you to check the
tire pressure in all of the tires on your vehicle monthly
and to maintain the proper pressure.
The TPMS consists of the following components:
•Receiver Module
•Four Tire Pressure Monitoring Sensors
•Tire Pressure Monitoring Telltale Light
358 STARTING AND OPERATING

The matching full-size spare wheel and tire assembly (if
equipped) has a tire pressure monitoring sensor. The
matching full-size spare can be used in place of any of the
four road tires. The TPMS will only monitor the pressure
in the full-size spare when it is used in place of a road
tire. Otherwise, a spare with a pressure below the low-
pressure limit will not cause the Tire Pressure Monitoring
Telltale Light to illuminate or the chime to sound.
Tire Pressure Monitoring Low Pressure Warnings
The Tire Pressure Monitoring Telltale Light will
illuminate in the instrument cluster and a chime
will sound when tire pressure is low in one or
more of the four active road tires. Should this occur, you
should stop as soon as possible, check the inflation
pressure of each tire on your vehicle, and inflate each tire
to the vehicle’s recommended cold placard pressure
value. Once the system receives the updated tire pres-
sures, the system will automatically update and the Tire
Pressure Monitoring Telltale Light will turn off. The vehicle may need to be driven for up to 20 minutes above
15 mph (25 km/h) in order for the TPMS to receive this
information.
Check TPMS Warning
When a system fault is detected, the Tire Pressure Moni-
toring Telltale Light will flash on and off for 75 seconds
and then remain on solid. The system fault will also
sound a chime. If the ignition key is cycled, this sequence
will repeat, providing the system fault still exists. The
Tire Pressure Monitoring Telltale Light will turn off when
the fault condition no longer exists. A system fault can
occur due to any of the following:
1. Jamming due to electronic devices or driving next to
facilities emitting the same radio frequencies as the TPMS
sensors.
2. Installing some form of aftermarket window tinting
that affects radio wave signals.
STARTING AND OPERATING 359
5