JEEP WRANGLER 2008 JK / 3.G Owners Manual

Follow the recommended tire rotation frequency for your
type of driving. Refer to the “Maintenance Schedule” in
Section 8 of this manual. More frequent rotation is
permissible if desired. The reasons for any rapid or
unusual wear should be corrected prior to rotation being
performed.
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 mi (1 km) after a three
hour period.Refer to the “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.
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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
off until the tire pressure is at or above recommended
cold placard pressure. Once the Tire Pressure Monitoring
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 automatically update and
the Tire Pressure Monitoring Telltale Light will extin-
guish once the updated tire pressures have been received.
The vehicle may need to be driven for up to 10 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 vehicle
may 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 recommended
cold placard pressure value.
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CAUTION!
The TPMS has been optimized for the original
equipment tires and wheels. TPMS pressures have
been established for the tire size equipped on your
vehicle. Undesirable system operation or sensor
damage may result when using replacement equip-
ment 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.
CAUTION!
After inspecting or adjusting the tire pressure always
reinstall the valve stem cap. This will prevent mois-
ture and dirt from entering the valve stem, which
could damage the Tire Pressure Monitoring 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.
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•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 TPM System 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. 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
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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 10
minutes above 15 mph (25 km/h) to receive this infor-
mation.
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.
2. Installing some form of aftermarket window tinting
that affects radio wave signals.3. Lots of snow or ice around the wheels or wheel
housings.
4. Using tire chains on the vehicle.
5. Using wheels/tires not equipped with TPM sensors.
NOTE:
If your vehicle is equipped with a matching
full-size spare wheel and tire assembly, it has a tire
pressure monitoring sensor, and can be monitored by the
Tire Pressure Monitoring System (TPMS). In the event
that the matching full-size spare tire is swapped with a
low pressure road tire, the next ignition key cycle will
still show the Tire Pressure Monitoring Telltale Light to
be ON, and a chime to sound. Driving the vehicle for up
to 10 minutes above 15 mph (25 km/h) will turn OFF the
Tire Pressure Monitoring Telltale Light as long as none of
the road tires are below the low pressure warning thresh-
old.
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NOTE:If your vehicle is not equipped with a matching
full-size spare wheel and tire assembly, it does not have a
tire pressure monitoring sensor in the spare tire. The
TPMS will not be able to monitor the tire pressure. If you
install the spare tire in place of a road tire that has a
pressure below the low-pressure warning limit, upon the
next ignition key cycle, a chime will sound and the Tire
Pressure Monitoring Telltale Light will turn ON. After
driving the vehicle for up to 10 minutes above 15 mph (25
km/h), the Tire Pressure Monitoring Telltale Light will
flash on and off for 75 seconds and then remain on solid.
For each subsequent ignition key cycle, a chime will
sound and the Tire Pressure Monitoring Telltale Light
will flash on and off for 75 seconds and then remain on
solid. Once you repair or replace the original road tire,
and reinstall it on the vehicle in place of the spare tire, the
TPMS will update automatically and the Tire Pressure
Monitoring Telltale Light will turn OFF, as long as no tire
pressure is below the low-pressure warning limit in any of the four active road tires. The vehicle may need to be
driven for up to 10 minutes above 15 mph (25 km/h) in
order for the TPMS to receive this information.
General Information
This device complies with part 15 of the FCC rules and
RSS 210 of Industry Canada. Operation is subject to the
following conditions:
•This device may not cause harmful interference.
•This device must accept any interference received,
including interference that may cause undesired op-
eration.
The tire pressure sensors are covered under one of the
following licenses:
United States ..................... KR5S120123
Canada ........................ 2671-S120123
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FUEL REQUIREMENTS
All engines (except 5.7L engines) are de-
signed to meet all emissions regulations
and provide excellent fuel economy and
performance when using high quality un-
leaded “regular” gasoline having an oc-
tane rating of 87. The use of premium
gasoline is not recommended. Under normal conditions,
the use of premium gasoline will not provide a benefit
over high quality regular gasoline, and in some circum-
stances may result in poorer performance.
Light spark knock at low engine speeds is not harmful to
your engine. However, continued heavy spark knock at
high speeds can cause damage and immediate service is
required. Poor quality gasoline can cause problems such as hard
starting, stalling and hesitations. If you experience these
symptoms, try another brand of gasoline before consid-
ering service for the vehicle.
Over 40 auto manufacturer’s worldwide have issued and
endorsed consistent gasoline specifications (the World-
wide Fuel Charter, WWFC) to define fuel properties
necessary to deliver enhanced emissions, performance,
and durability for your vehicle. The manufacturer recom-
mends the use of gasoline that meets the WWFC speci-
fications if they are available.
Reformulated Gasoline
Many areas of the country require the use of cleaner
burning gasoline referred to as “Reformulated Gasoline.”
Reformulated gasoline contains oxygenates, and are spe-
cifically blended to reduce vehicle emissions and im-
prove air quality.
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The manufacturer supports the use of reformulated gaso-
line. Properly blended reformulated gasoline will pro-
vide excellent performance and durability for the engine
and fuel system components.
Gasoline/Oxygenate Blends
Some fuel suppliers blend unleaded gasoline with oxy-
genates such as 10% ethanol, MTBE, and ETBE. Oxygen-
ates are required in some areas of the country during the
winter months to reduce carbon monoxide emissions.
Fuels blended with these oxygenates may be used in
your vehicle.
CAUTION!
DO NOT use gasolines containing Methanol. Use of
these blends may result in starting and drivability
problems and may damage critical fuel system
components.Problems that result from using methanol/gasoline
blends are not the responsibility of the manufacturer.
While MTBE is an oxygenate made from Methanol, it
does not have the negative effects of Methanol.
MMT In Gasoline
MMT is a manganese containing metallic additive that is
blended into some gasoline to increase the octane num-
ber. Gasoline blended with MMT offers no performance
advantage beyond gasoline of the same octane number
without MMT. Gasoline blended with MMT has shown
to reduce sparkplug life and reduce emission system
performance in some vehicles. The manufacturer recom-
mends that gasoline without MMT be used in your
vehicle. The MMT content of gasoline may not be indi-
cated on the gasoline pump, therefore, you should ask
your gasoline retailer if the gasoline contains MMT.
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It is even more important to look for gasoline without
MMT in Canada, because MMT can be used at levels
higher than those allowed in the United States.
MMT is prohibited in Federal and California-
reformulated gasoline.
Materials Added To Fuel
All gasoline sold in the United States is required to
contain effective detergent additives. Use of additional
detergents or other additives are not needed under
normal conditions and would result in additional cost.
Therefore you should not have to add anything to the
fuel.
Fuel System Cautions
CAUTION!
Follow these guidelines to maintain your vehicle’s
performance:
•The use of leaded gasoline is prohibited by Federal
law. Using leaded gasoline can impair engine perfor-
mance, and damage the emission control system.
•An out-of-tune engine, or certain fuel or ignition
malfunctions, can cause the catalytic converter to
overheat. If you notice a pungent burning odor or
some light smoke, your engine may be out of tune or
malfunctioning and may require immediate service.
Contact your authorized dealer for service assistance.
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•The use of fuel additives which are now being sold as
octane enhancers is not recommended. Most of these
products contain high concentrations of methanol.
Fuel system damage or vehicle performance problems
resulting from the use of such fuels or additives is not
the responsibility of the manufacturer.
NOTE: Intentional tampering with emissions control
systems can result in civil penalties being assessed
against you.
Carbon Monoxide Warnings
WARNING!
Carbon monoxide (CO) in exhaust gases is deadly.
Follow the precautions below to prevent carbon
monoxide poisoning:
•Do not inhale exhaust gases. They contain carbon
monoxide, a colorless and odorless gas which can kill.
Never run the engine in a closed area, such as a
garage, and never sit in a parked vehicle with the
engine running for an extended period. If the vehicle is
stopped in an open area with the engine running for
more than a short period, adjust the ventilation system
to force fresh, outside air into the vehicle.
•Guard against carbon monoxide with proper mainte-
nance. Have the exhaust system inspected every time
the vehicle is raised. Have any abnormal conditions
repaired promptly. Until repaired, drive with all side
windows fully open.
•Keep the swing gate closed when driving your vehicle
to prevent carbon monoxide and other poisonous
exhaust gases from entering the vehicle.
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