2012 JEEP WRANGLER tire pressure

•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.
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,, a “LOW TIRE
PRESSURE” message will display in the EVIC, and
an audible 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
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STARTING AND OPERATING 457

extinguish once the updated tire pressures have been
received. The vehicle may need to be driven for up to
20 minutes above 15 mph (24 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.
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 20 minutes above 15 mph (24 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 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.
458 STARTING AND OPERATING

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 20 minutes
above 15 mph (24 km/h), the “Tire Pressure Monitor-
ing 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 Tell-
tale 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 bedriven for up to 20 minutes above 15 mph (24 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
operation.
The tire pressure sensors are covered under one of the
following licenses:
United States ................... MRXC4N3MF9
Canada ...................... 2546A-C4N3MF95
STARTING AND OPERATING 459

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.
Loading
The actual total weight and the weight of the front and
rear of your vehicle at the ground can best be determined
by weighing it when it is loaded and ready for operation.The entire vehicle should first be weighed on a commer-
cial scale to ensure that the GVWR has not been ex-
ceeded. The weight on the front and rear of the vehicle
should then be determined separately to be sure that the
load is properly distributed over front and rear axle.
Weighing the vehicle may show that the GAWR of either
the front or rear axles has been exceeded, but the total
load is within the specified GVWR. If so, weight must be
shifted from front to rear, or rear to front, as appropriate
until the specified weight limitations are met. Store the
heavier items down low and be sure that the weight is
distributed equally. Stow all loose items securely before
driving.
Improper weight distributions can have an adverse affect
on the way your vehicle steers and handles, and the way
the brakes operate.
468 STARTING AND OPERATING

WARNING! (Continued)
4. Tongue weight rating for the trailer hitch utilized
(This requirement may limit the ability to always
achieve the 10% to 15% range of tongue weight as a
percentage of total trailer weight).
Towing Requirements – Tires

Proper tire inflation pressures are essential to the safe
and satisfactory operation of your vehicle. Refer to
“Tires – General Information” in “Starting and Oper-
ating” for proper tire inflation procedures.
Check the trailer tires for proper tire inflation pres-
sures before trailer usage.
Check for signs of tire wear or visible tire damage
before towing a trailer. Refer to “Tires – General
Information” in “Starting and Operating” for the
proper inspection procedure.
When replacing tires, refer to “Tires – General Infor-
mation” in “Starting and Operating” for information
on replacement tires and for proper tire replacement
procedures. Replacing tires with a higher load carry-
ing capacity will not increase the vehicle’s GVWR and
GAWR limits.
Towing Requirements – Trailer Brakes

Do not interconnect the hydraulic brake system or
vacuum system of your vehicle with that of the trailer.
This could cause inadequate braking and possible
personal injury.
An electronically-actuated trailer brake controller is
required when towing a trailer with electronically
actuated brakes. When towing a trailer equipped with
a hydraulic surge-actuated brake system, an electronic
brake controller is not required.
480 STARTING AND OPERATING

NOTE:There are steps that you can take to slow down
an impending overheat condition:
•If your air conditioner (A/C) is on, turn it off. The A/C
system adds heat to the engine cooling system and
turning the A/C off can help remove this heat.
•You can also turn the temperature control to maximum
heat, the mode control to floor and the blower control
to high. This allows the heater core to act as a
supplement to the radiator and aids in removing heat
from the engine cooling system.
WARNING!
You or others can be badly burned by hot engine
coolant (antifreeze) or steam from your radiator. If
you see or hear steam coming from under the hood,
do not open the hood until the radiator has had time
to cool. Never try to open a cooling system pressure
cap when the radiator or coolant bottle is hot.
JACKING AND TIRE CHANGING
WARNING!
•Do not attempt to change a tire on the side of the
vehicle close to moving traffic. Pull far enough off
the road to avoid the danger of being hit when
operating the jack or changing the wheel.
•Being under a jacked-up vehicle is dangerous. The
vehicle could slip off the jack and fall on you. You
could be crushed. Never put any part of your body
under a vehicle that is on a jack. If you need to get
under a raised vehicle, take it to a service center
where it can be raised on a lift.
•Never start or run the engine while the vehicle is
on a jack.
(Continued)
6
WHAT TO DO IN EMERGENCIES 493

FREEING A STUCK VEHICLE
If your vehicle becomes stuck in mud, sand or snow, it
can often be moved by a rocking motion. Turn your
steering wheel right and left to clear the area around the
front wheels. Then shift back and forth between DRIVE
and REVERSE (with automatic transmission) or 1st gear
and REVERSE (with manual transmission). Using mini-
mal accelerator pedal pressure to maintain the rocking
motion, without spinning the wheels, is most effective.
CAUTION!
Racing the engine or spinning the wheels may lead to
transmission overheating and failure. Allow the en-
gine to idle with the shift lever in NEUTRAL for at
least one minute after every five rocking-motion
cycles. This will minimize overheating and reduce
the risk of transmission failure during prolonged
efforts to free a stuck vehicle.NOTE:
If your vehicle is equipped with Traction Con-
trol or Electronic Stability Control (ESC), turn the system
OFF before attempting to “rock” the vehicle.
CAUTION!
•When “rocking” a stuck vehicle by moving be-
tween DRIVE and REVERSE (with automatic
transmission) or 1st gear and REVERSE (with
manual transmission), do not spin the wheels
faster than 15 mph (24 km/h), or drivetrain damage
may result.
•Revving the engine or spinning the wheels too fast
may lead to transmission overheating and failure.
It can also damage the tires. Do not spin the
wheels above 30 mph (48 km/h) while in gear (no
transmission shifting occurring).6
WHAT TO DO IN EMERGENCIES 505

Cooling System
WARNING!
You or others can be badly burned by hot engine
coolant (antifreeze) or steam from your radiator. If
you see or hear steam coming from under the hood,
do not open the hood until the radiator has had time
to cool. Never try to open a cooling system pressure
cap when the radiator or coolant bottle is hot.
Engine Coolant Checks
Check the engine coolant (antifreeze) protection every
12 months (before the onset of freezing weather, where
applicable). If the engine coolant (antifreeze) is dirty or
rusty in appearance, the system should be drained,
flushed and refilled with fresh engine coolant (anti-
freeze). Check the front of the A/C condenser (ifequipped) or radiator for any accumulation of bugs,
leaves, etc. If dirty, clean by gently spraying water from a
garden hose vertically down the face of the A/C con-
denser (if equipped) or the back of the radiator core.
Check the engine cooling system hoses for brittle rubber,
cracking, tears, cuts, and tightness of the connection at
the coolant recovery bottle and radiator. Inspect the
entire system for leaks.
With the engine at normal operating temperature (but
not running), check the cooling system pressure cap for
proper vacuum sealing by draining a small amount of
engine coolant (antifreeze) from the radiator drain cock.
If the cap is sealing properly, the engine coolant (anti-
freeze) will begin to drain from the coolant recovery
bottle. DO NOT REMOVE THE COOLANT PRESSURE
CAP WHEN THE COOLING SYSTEM IS HOT.
530 MAINTAINING YOUR VEHICLE