The Tire Pressure Monitor System (TPMS) consists of the
following components:
•Receiver Module
• Four Tire Pressure Monitoring Sensors
• Various Tire Pressure Monitoring System Messages,
which display in the instrument cluster, and a graphic
displaying tire pressures
• 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.
Tire Pressure Monitoring Low Pressure Warnings
The Tire Pressure Monitoring Telltale Light will illu-
minate in the instrument cluster, and an audible
chime will be activated, when one or more of the four active
road tire pressures are low. In addition, the instrument
cluster will display a “LOW TIRE” message for a minimum
of five seconds. An “Inflate to XX” message and a graphic display of the pressure value(s) with the low tire(s) high-
lighted or in a different color will also be displayed. Refer to
“Instrument Cluster Display” in “Getting To Know Your
Instrument Panel” for further information.
NOTE:
Your system can be set to display pressure units in
PSI, kPa, or BAR.
Tire Pressure Monitor Display
232 SAFETY
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) when swapped
with a low pressure road tire. In the event that the
matching full-size spare tire is swapped with a low
pressure road tire, the next ignition switch cycle will still
show the “Tire Pressure Monitoring Telltale Light” to be
ON, a chime to sound, a “LOW TIRE” message to
appear in the instrument cluster, and the graphic display
will still show the Inflate to XXmessage and the low
tire pressure value highlighted or shown in a different
color. Driving the vehicle for up to 20 minutes above
15 mph (24 km/h) will turn OFF the “Tire Pressure
Monitoring Telltale Light” as long as none of road tires
are below the low pressure warning threshold.
• 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 switch cycle, the “Tire Pressure Monitoring Telltale Light” will remain ON, a chime will sound, and
the instrument cluster will still display the
Inflate to XX
message and a highlighted or different color pressure
value in the graphic display. After driving the vehicle for
up to 20 minutes above 15 mph (24 km/h), the “Tire
Pressure Monitoring Telltale Light” will flash on and off
for 75 seconds and then remain on solid. In addition, the
instrument cluster will display a “SERVICE TPM SYS-
TEM message for a minimum of five seconds and then
display dashes (- -) in place of the pressure value. For
each subsequent ignition switch cycle, a chime will
sound, the “Tire Pressure Monitoring Telltale Light” will
flash on and off for 75 seconds and then remain on solid,
and the instrument cluster will display a SERVICE TPM
SYSTEM message for a minimum of five seconds and
then display dashes (- -) in place of the pressure value.
• 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.
In addition, the “Tire Pressure Monitoring Telltale Light”
will turn OFF and the graphic in the instrument cluster will
display a new pressure value instead of dashes (- -), 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
234 SAFETY
The transfer case is intended to be driven in the 2H
position for normal street and highway conditions, such as
hard-surfaced roads.
In the event that additional traction is required, the transfer
case 4H and 4L positions can be used to lock the front and
rear driveshafts together, forcing the front and rear wheels
to rotate at the same speed. The 4H and 4L positions are
intended for loose, slippery road surfaces only and not
intended for normal driving. Driving in the 4H and 4L
positions on hard-surfaced roads will cause increased tirewear and damage to the driveline components. Refer to
“Shifting Procedures” in this section for further informa-
tion on shifting into 4H or 4L.
The “4WD Indicator Light” (located in the instrument
cluster) alerts the driver that the vehicle is in four-wheel
drive, and the front and rear driveshafts are locked to-
gether. The light will illuminate when the transfer case is
shifted into the 4H position.
NOTE:
Do not attempt to shift when only the front or rear
wheels are spinning. The transfer case is not equipped with
a synchronizer, and the front and rear driveshaft speeds
must be equal for a shift to take place. Shifting while the
front or rear wheels are spinning at different speeds can
cause damage to the transfer case.
When operating your vehicle in 4L, the engine speed will
be approximately three times (four times for Rubicon
models) that of the 2H or 4H positions at a given road
speed. Take care not to overspeed the engine.
Proper operation of four-wheel drive vehicles depends on
tires of equal size, type, and circumference on each wheel.
Any difference will adversely affect shifting and cause
damage to the transfer case.
Four-Wheel Drive Gear Selector
302 STARTING AND OPERATING
included on this label and indicates the Month, Day and
Hour of manufacture. The bar code that appears on the
bottom of the label is your VIN.
Gross Vehicle Weight Rating (GVWR)
The GVWR is the total permissible weight of your vehicle
including driver, passengers, vehicle, options and cargo.
The label also specifies maximum capacities of front and
rear axle systems (GAWR). Total load must be limited so
GVWR and front and rear GAWR are not exceeded.
Payload
The payload of a vehicle is defined as the allowable load
weight a truck can carry, including the weight of the driver,
all passengers, options and cargo.
Gross Axle Weight Rating (GAWR)
The GAWR is the maximum permissible load on the front
and rear axles. The load must be distributed in the cargo
area so that the GAWR of each axle is not exceeded.
Each axle GAWR is determined by the components in the
system with the lowest load carrying capacity (axle,
springs, tires or wheels). Heavier axles or suspensioncomponents sometimes specified by purchasers for in-
creased durability does not necessarily increase the vehi-
cle’s GVWR.
Tire Size
The tire size on the Vehicle Certification Label represents
the actual tire size on your vehicle. Replacement tires must
be equal to the load capacity of this tire size.
Rim Size
This is the rim size that is appropriate for the tire size
listed.
Inflation Pressure
This is the cold tire inflation pressure for your vehicle for
all loading conditions up to full GAWR.
Curb Weight
The curb weight of a vehicle is defined as the total weight
of the vehicle with all fluids, including vehicle fuel, at full
capacity conditions, and with no occupants or cargo loaded
into the vehicle. The front and rear curb weight values are
determined by weighing your vehicle on a commercial
scale before any occupants or cargo are added.
314 STARTING AND OPERATING
Tire MarkingsNOTE:
•P (Passenger) — Metric tire sizing is based on U.S.
design standards. P-Metric tires have the letter “P”
molded into the sidewall preceding the size designation.
Example: P215/65R15 95H.
• European — Metric tire sizing is based on European
design standards. Tires designed to this standard have
the tire size molded into the sidewall beginning with the
section width. The letter Pis absent from this tire size
designation. Example: 215/65R15 96H.
• LT (Light Truck) — Metric tire sizing is based on U.S.
design standards. The size designation for LT-Metric
tires is the same as for P-Metric tires except for the letters
“LT” that are molded into the sidewall preceding the
size designation. Example: LT235/85R16.
• Temporary spare tires are designed for temporary emer-
gency use only. Temporary high pressure compact spare
tires have the letter “T” or “S” molded into the sidewall
preceding the size designation. Example: T145/80D18
103M.
• High flotation tire sizing is based on U.S. design stan-
dards and it begins with the tire diameter molded into
the sidewall. Example: 31x10.5 R15 LT.
Tire Markings
1 — U.S. DOT Safety Standards
Code (TIN) 4 — Maximum Load
2 — Size Designation 5 — Maximum Pressure
3 — Service Description 6 — Treadwear, Traction and
Temperature Grades
406 SERVICING AND MAINTENANCE
Tire Identification Number (TIN)
The TIN may be found on one or both sides of the tire;
however, the date code may only be on one side. Tires with
white sidewalls will have the full TIN, including the date
code, located on the white sidewall side of the tire. Look forthe TIN on the outboard side of black sidewall tires as
mounted on the vehicle. If the TIN is not found on the
outboard side, then you will find it on the inboard side of
the tire.
EXAMPLE:
DOT MA L9 ABCD 0301
DOT = Department of Transportation
– This symbol certifies that the tire is in compliance with the U.S. Department of Transportation tire safety
standards and is approved for highway use
MA = Code representing the tire manufacturing location (two digits)
L9 = Code representing the tire size (two digits)
ABCD = Code used by the tire manufacturer (one to four digits)
03 = Number representing the week in which the tire was manufactured (two digits)
– 03 means the 3rd week
01 = Number representing the year in which the tire was manufactured (two digits)
– 01 means the year 2001
– Prior to July 2000, tire manufacturers were only required to have one number to represent the year in
which the tire was manufactured. Example: 031 could represent the 3rd week of 1981 or 1991
8
SERVICING AND MAINTENANCE 407
Tire Terminology And Definitions
TermDefinition
B-Pillar The vehicle B-Pillar is the structural member of the body located be-
hind the front door.
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 sitting for a minimum of three hours. In-
flation pressure is measured in units of PSI (pounds per square inch)
or kPa (kilopascals).
Maximum Inflation Pressure The maximum inflation pressure is the maximum permissible cold
tire inflation pressure for this tire. The maximum inflation pressure is
molded into the sidewall.
Recommended Cold Tire Inflation Pressure Vehicle manufacturer’s recommended cold tire inflation pressure as
shown on the tire placard.
Tire Placard A label permanently attached to the vehicle describing the vehicle’s
loading capacity, the original equipment tire sizes and the recom-
mended cold tire inflation pressures.
408 SERVICING AND MAINTENANCE
Tire And Loading Information Placard
This placard tells you important information about the:
•Number of people that can be carried in the vehicle.
• Total weight your vehicle can carry.
• Tire size designed for your vehicle.
• 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 in “Vehicle Loading” in the “Starting And Operat-
ing” section of this manual.
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 Load-
ing” in the “Starting And Operating” section of this
manual.
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 lbs” on the Tire and Loading Information placard. The
combined weight of occupants, cargo/luggage and trailer
tongue weight (if applicable) should never exceed the
weight referenced here.
Tire And Loading Information Placard
410 SERVICING AND MAINTENANCE