2012 JEEP GRAND CHEROKEE tire pressure

•The TPMS is not a substitute for proper tire mainte-
nance, and it is the driver ’s responsibility to maintain
correct tire pressure using an accurate tire gauge, 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.
Premium 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 regularly
check the tire pressure in all of your tires and to maintain
the proper pressure.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 Electronic Vehicle Information
Center (EVIC), and a graphic displaying tire pressures
•Tire Pressure Monitoring Telltale Light
Tire Pressure Monitoring Low Pressure Warnings
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. In addition, the
EVIC will display one or more Low Pressure messages
(Left Front, Left Rear, Right Front, Right Rear) for a
minimum of five seconds, and a graphic display of the
pressure value(s) with the low tire(s) “flashing.” Refer to
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“Electronic Vehicle Information Center (EVIC)” in “Un-
derstanding Your Instrument Panel” for further informa-
tion.
NOTE:Your system can be set to display pressure units
in PSI, kPa, or BAR.
Should a low tire condition occur on any of the four
active road tire(s), you should stop as soon as possible,and inflate the low tire(s) that is “flashing” on the graphic
display to the vehicle’s recommended cold tire pressure.
The system will automatically update, the graphic dis-
play of the pressure value(s) will stop “flashing,” and the
Tire Pressure Monitoring Telltale Light will extinguish
once the updated tire pressure(s) 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.
SERVICE TPM SYSTEM Warning
The Tire Pressure Monitoring Telltale Light will flash on
and off for 75 seconds, and remain on solid when a
system fault is detected. The system fault will also sound
a chime. The EVIC will display a “SERVICE TPM SYS-
TEM” message for a minimum of five seconds. This
message is then followed by a graphic display, with “- -“
in place of the pressure value(s), indicating which Tire
Pressure Monitoring Sensor(s) is not being received.
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NOTE:Your system can be set to display pressure units
in PSI, kPa, or BAR.
If the ignition switch is cycled, this sequence will repeat,
providing the system fault still exists. If the system fault
no longer exists, the Tire Pressure Monitoring Telltale
Light will no longer flash, theSERVICE TPM SYSTEMmessage will not be present, and a pressure value will be
displayed instead of dashes. A system fault can occur by
any of the following:
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.
The EVIC will also display aSERVICE TPM SYSTEM
message for a minimum of five seconds when a system
fault is detected possibly related to the trigger compo-
nent an incorrect sensor location fault. In this case, the
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SERVICE TPM SYSTEMmessage is then followed by a
graphic display, with pressure values still shown. This
indicates the pressure values are still being received from
the TPM Sensors but they may not be located in the
correct vehicle position. However, the system still needs
to be serviced as long as theSERVICE TPM SYSTEM
message exists.
NOTE:There is no 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 Pres-
sure Monitoring Telltale Light will remain ON, a chime
will sound, and the EVIC will still display a “flashing”
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 EVIC will display a “SERVICE TPM SYSTEMmes-
sage for three 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 sec-
onds and then remain on solid, and the EVIC will display
aSERVICE TPM SYSTEMmessage for three 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 EVIC 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
be driven for up to 20 minutes above 15 mph (24 km/h)
in order for the TPMS to receive this information.
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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...................MRXC4W4MA4
Canada.....................2546A-C4W4MA4
FUEL REQUIREMENTS
6.4L Engine
The 6.4L engine is designed to meet all
emissions regulations and provide excel-
lent fuel economy and performance when
using high-quality premium unleaded
gasoline with an octane rating of 91 or
higher.
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 experi-
ence these symptoms, try another brand of gasoline
before considering service for the vehicle.
Over 40 auto manufacturers worldwide have issued and
endorsed consistent gasoline specifications (the World-
wide Fuel Charter, WWFC) which define fuel properties
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Gross Vehicle Weight Rating (GVWR)
The GVWR is the total permissible weight of your vehicle
including driver, passengers, vehicle, options, trailer
tongue weight, and cargo. The label also specifies maxi-
mum 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 or any given vehicle 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’s GAWR is determined by the components in
the system with the lowest load carrying capacity (axle,springs, tires, or wheels). Heavier axles or suspension
components, sometimes specified by purchasers for in-
creased durability, does not necessarily increase the ve-
hicle’s GVWR.
Tire Size
The tire size on the 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
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TRAILER TOWING
In this section you will find safety tips and information
on limits to the type of towing you can reasonably do
with your vehicle. Before towing a trailer carefully re-
view this information to tow your load as efficiently and
safely as possible.
WARNING!
•Do not tow when the “Tire Pressure Monitoring
Telltale Light” is illuminated. Failure to follow
this could result in loss of control and serious
injury.
•The tailpipes may be hot and you could be seri-
ously injured if you come into contact with the
tailpipes.
To maintain warranty coverage, follow the requirements
and recommendations in this manual concerning ve-
hicles used for trailer towing.
Common Towing Definitions
The following trailer towing related definitions will assist
you in understanding the following information:
Gross Vehicle Weight Rating (GVWR)
The GVWR is the total allowable weight of your vehicle.
This includes driver, passengers, cargo and tongue
weight. The total load must be limited so that you do not
exceed the GVWR.
Gross Trailer Weight (GTW)
The GTW is the weight of the trailer plus the weight of all
cargo, consumables and equipment (permanent or tem-
porary) loaded in or on the trailer in itsloaded and
ready for operationcondition. The recommended way to
measure GTW is to put your fully loaded trailer on a
vehicle scale. The entire weight of the trailer must be
supported by the scale.
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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 proper
inspection procedure.
When replacing tires, refer to “Tires – General Infor-
mation” in “Starting and Operating” for proper tire
replacement procedures. Replacing tires with a higher
load carrying capacity will not increase the vehicle’s
GVWR and GAWR limits.
Towing Requirements – Trailer Brakes

Donotinterconnect 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.
Trailer brakes are recommended for trailers over
1,000 lbs (454 kg) and required for trailers in excess of
2,000 lbs (907 kg).
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