2009 JEEP WRANGLER tire pressure

Tire 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. This will prevent
moisture and dirt from entering the valve stem,
which could damage the Tire Pressure Monitoring
Sensor.
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 infla-
tion pressure molded into the tire side wall.
Check tire pressures more often if subject to a wide range
of outdoor temperatures, as tire pressures vary with
temperature changes.
Tire Placard Location (Four-Door Models)
344 STARTING AND OPERATING

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.
Tire pressure may increase from 2 to 6 psi (13 to 40 kPa)
during operation. DO NOT reduce this normal pressure
buildup 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 under 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 maximum capacity at
continuous speeds above 75 mph (120 km/h).
5
STARTING AND OPERATING 345

Tread Wear Indicators
Tread wear indicators are in the original equipment tires
to help you in determining when your tires should be
replaced.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 tread is worn to the
tread wear indicators, the tire should be replaced.
Life of Tire
The service life of a tire is dependent upon varying
factors including but not limited to:
•Driving style
•Tire pressure
•Distance driven
1 — Worn Tire
2 — New Tire
5
STARTING AND OPERATING 347

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 unmounted 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 (see the paragraph on tread
wear indicators). Refer to the Tire and Loading Informa-
tion placard for the size designation of your tire. 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, han-
dling, and ride of your vehicle. We recommend that you
refer to your original equipment or contact an authorized
tire dealer with any questions you may have on tire
specifications or capability.
348 STARTING AND OPERATING

The suggested rotation method is the “forward-cross”
shown in the following diagram.
TIRE PRESSURE MONITOR SYSTEM (TPMS)
The Tire Pressure Monitoring System (TPMS) will warn
the driver of a low tire pressure based on the vehicle
recommended 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 a vehicle has not been driven for more than
three hours, or driven less than 1 mile (1.6 km) after a
three-hour period.
Refer to “Tires — General Informa-
tion” 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
threshold for any reason, including low temperature
effects, or 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
Tire Rotation
5
STARTING AND OPERATING 351

off until the tire pressure is at or above recommended
cold placard pressure. Once the “Tire Pressure Monitor-
ing Telltale Light” has been illuminated, the tire pressure
must be increased to the recommended cold placard
pressure in order for the “Tire Pressure Monitoring
Telltale Light” to be turned OFF. The system will auto-
matically update and the “Tire Pressure Monitoring
Telltale Light” will extinguish once the updated tire
pressures have been received. The vehicle may need to be
driven for up to 20 minutes above 15 mph (25 km/h) to
receive this information.
For example, your vehicle may have a recommended
cold (parked for more than three hours) air pressure of
35 psi (241 kPa). If the ambient temperature is 68°F (20°C)
and the measured tire pressure is 30 psi (207 kPa), a
temperature drop to 20°F (-7°C) will decrease the tire
pressure to approximately 26 psi (179 kPa). This tire
pressure is sufficiently low enough to turn ON the “Tire
Pressure Monitoring Telltale Light.” Driving the vehiclemay cause the tire pressure to rise to approximately
30 psi (207 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 have been inflated to the vehicle’s recom-
mended cold placard pressure value.
CAUTION!
•The TPMS has been optimized for the original
equipment tires and wheels. The TPMS pressures
have been established for the tire size equipped
on your vehicle. Undesirable system operation or
sensor damage may result when using replace-
ment 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.
(Continued)
352 STARTING AND OPERATING

CAUTION! (Continued)
•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.
NOTE:
•The TPMS is not intended to replace normal tire care
and maintenance, nor 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, even if under-inflation has not
reached the level to trigger illumination of the “Tire
Pressure Monitoring 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 your tires regularly and to maintain
the proper pressure.
5
STARTING AND OPERATING 353

The Tire Pressure Monitor System (TPMS) consists of the
following components:
•Receiver Module
•Four Tire Pressure Monitoring Sensors
•Tire Pressure Monitoring Telltale Light
A tire pressure monitoring sensor is located in the spare
wheel if the vehicle is equipped with a matching full size
spare wheel and tire assembly. The matching full size
spare tire can be used in place of any of the four road
tires. A low spare tire will not cause the “Tire Pressure
Monitoring Telltale Light” to illuminate or the chime to
sound. The “Tire Pressure Monitoring Telltale Light” will
illuminate in the instrument cluster, and an au-
dible chime will be activated when one or more of
the four active road tire pressures are low. 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. The system will automatically update
and the “Tire Pressure Monitoring Telltale Light” will
extinguish once the updated tire pressures have been
received. The vehicle may need to be driven for up to
20 minutes above 15 mph (25 km/h) to receive this
information.
The “Tire Pressure Monitoring Telltale Light” will flash
on and off for 75 seconds, and will remain on solid when
a system fault is detected. The system fault will also
sound a chime. If the ignition key is cycled, this sequence
will repeat, providing the system fault still exists. A
system fault can occur by any of the following scenarios:
1. Jamming due to electronic devices or driving next to
facilities emitting the same Radio Frequencies as the TPM
sensors.
354 STARTING AND OPERATING