2008 JEEP WRANGLER UNLIMITED inflation pressure

21. Odometer/Trip Odometer Reset Button
Press this button to change the display from odometer to
either of two trip odometer settings. Trip A or Trip B will
appear when in the trip odometer mode. Press and hold
the button for two seconds to reset the trip odometer to 0
miles or kilometers. The odometer must be in trip mode
to reset.
22. Transmission Range Indicator
This display indicator shows the automatic transmission
gear selection.
23. Tire Pressure Monitoring Telltale LightEach tire, including the spare (if provided),
should be checked monthly when cold and
inflated to the inflation pressure recommended
by the vehicle manufacturer on the vehicle
placard or tire inflation pressure label. (If your vehicle
has tires of a different size than the size indicated on the vehicle placard or tire inflation pressure label, you should
determine the proper tire inflation pressure for those
tires.)
As an added safety feature, your vehicle has been
equipped with a tire pressure monitoring system (TPMS)
that illuminates a low tire pressure telltale when one or
more of your tires is significantly under-inflated. Accord-
ingly, when the low tire pressure telltale illuminates, you
should stop and check your tires as soon as possible, and
inflate them to the proper pressure. Driving on a signifi-
cantly 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.
Please note that the TPMS is not a substitute for proper
tire maintenance, 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 TPMS
low tire pressure telltale.

WARNING!
Significant over or under-inflation of tires, or mixing
sizes of tires or wheels on the vehicle can lead to loss
of braking effectiveness.
The Anti-Lock Brake System conducts a low speed self-
test at about 12 mph (20 km/h). If for any reason, your
foot is on the brake when the vehicle reaches 12 mph (20
km/h), this check will be delayed until 25 mph (40
km/h).
The Anti-Lock Brake System pump motor runs during
the self-test, and during an ABS stop, to provide the
regulated hydraulic pressure. The motor pump makes a
low humming noise during operation, this is normal. During off-road use, loss of traction can temporarily
defeat the system and cause the warning light to illumi-
nate. Turn the ignition OFF and ON again to restore
Anti-Lock Brake System function.

Tire and Loading Information Placard
This placard tells you important information about
the
1) number of people that can be carried in the vehicle
2) total weight your vehicle can carry
3) tire size designed for your vehicle4) cold tire inflation pressures for the front, rear and
spare tires.
Loading
The vehicle maximum load on the tire must not exceed
the load carrying capacity of the tire on your vehicle. You
will not exceed the tire’s load carrying capacity if you
adhere to the loading conditions, tire size and cold tire
inflation pressures specified on the Tire and Loading
Information placard and the Vehicle Loading section of
this manual. Refer to “Vehicle Loading” in this section.
NOTE:
Under a maximum loaded vehicle condition,
gross axle weight ratings (GAWRs) for the front and rear
axles must not be exceeded. For further information on
GAWRs, vehicle loading and trailer towing. Refer to
“Vehicle Loading” in this section.
To determine the maximum loading conditions of your
vehicle, locate the statement “The combined weight of
occupants and cargo should never exceed XXX kg or XXX

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 consump-
tion.
Ride Comfort and Vehicle Stability
Proper tire inflation contributes to a comfortable ride.
Over-inflation produces a jarring and uncomfortable
ride.
Tire Inflation Pressures

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 vehicleloading 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.

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.

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.
334 STARTING AND OPERATING

Storage, Vehicle...................... 266,419
Storing Your Vehicle ...................... 419
Sunrider ........................... 161,164
Supplemental Restraint System - Airbag ........ 51
Sway Bar Disconnect, Electronic ............. 292
Swing Gate, Rear ......................... 38
System, Navigation ...................... 250
System, Remote Starting .................... 25
Tachometer ............................ 209
Temperature Gauge, Engine Coolant .......... 209
Tether Anchor, Child Restraint ............... 68
Theft System Arming ...................... 18
Theft System Disarming .................... 18
Tilt Steering Column ..................... 101
Tip Start .............................. 272
Tire and Loading Information Placard ......317,318
Tire Identification Number (TIN) ............. 316
Tire Markings .......................... 313 Tire Safety Information
.................... 313
Tires .............................. 321,442
Air Pressure .......................... 322
Alignment and Balance .................. 328
Chains .............................. 329
Changing ............................ 366
General Information .................... 321
High Speed .......................... 324
Inflation Pressures ..................... 322
Jacking ........................... 366,369
Load Capacity ..................... 317,318
Pressure Monitor System (TPMS) ........... 330
Pressure Warning Light .................. 210
Quality Grading ....................... 442
Radial .............................. 325
Replacement ......................... 327
Rotation ............................. 329
Safety .............................. 313
Sizes ............................... 314
460 INDEX