2012 JEEP GRAND CHEROKEE inflation pressure

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 the vehicle has not been driven for at least
three hours, or driven less than 1 mile (1.6 km) after a
three-hour period.Refer to “Tires – General Informa-
tion” in “Starting and Operating” 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.
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 tire placard pressure. Once the low tire pressure
warning has been illuminated, the tire pressure must be
increased to the recommended cold tire 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 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.
For example, your vehicle has a recommended cold
(parked for more than three hours) tire placard pressure
of 33 psi (227 kPa). If the ambient temperature is 68°F
(20°C) and the measured tire pressure is 28 psi (193 kPa),
a temperature drop to 20°F (-7°C) will decrease the tire
pressure to approximately 24 psi (165 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
28 psi (193 kPa), but the Tire Pressure Monitoring Telltale
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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 tire pressure value.
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
equipment that is not of the same size, type, and/or
style. Aftermarket wheels can cause sensor dam-
age. Do not use aftermarket tire sealants or balance
beads if your vehicle is equipped with a TPMS, as
damage to the sensors may result.(Continued)
CAUTION! (Continued)
•After inspecting or adjusting the tire pressure
always reinstall the valve stem cap. This will
prevent moisture and dirt from entering the valve
stem, which could damage the Tire Pressure Moni-
toring Sensor.
NOTE:
•The TPMS is not intended to replace normal tire care
and maintenance, or 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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STARTING AND OPERATING 501

•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.
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 regularly
check the tire pressure in all of your tires, and to maintain
the proper pressure. The TPMS consists of the following components:
•Receiver Module
•Four Tire Pressure Monitoring Sensors
•Tire Pressure Monitoring Telltale Light
A low spare tire will not cause the Tire Pressure Moni-
toring Telltale Light to illuminate, a warning message to
appear, 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 instru-
ment cluster for 5 seconds, 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
502 STARTING AND OPERATING

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
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
522 STARTING AND OPERATING

Towing Requirements – Tires

Do not attempt to tow a trailer while using a compact
spare tire.
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

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.
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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STARTING AND OPERATING 533

Illuminated Entry........................ 23
Immobilizer (Sentry Key) ................... 18
Infant Restraint ........................ 81,82
Inflation Pressure Tires .................... 488
Information Center, Vehicle ................. 295
Inside Rearview Mirror ................... 107
Instrument Cluster .................... 284,285
Instrument Panel and Controls .............. 283
Instrument Panel Lens Cleaning ............. 609
Integrated Power Module (Fuses) ............ 610
Interior Appearance Care .................. 608
Intermittent Wipers (Delay Wipers) ........... 190
Introduction ............................. 4
Inverter, Power ......................... 262
Jack Location ........................... 550
Jack Operation ....................... 549,552
Jacking Instructions ...................... 552
Jump Starting .......................... 559 Key-In Reminder
......................... 18
Key, Programming ........................ 20
Key, Replacement ........................ 19
Key, Sentry (Immobilizer) ................... 18
Keyless Enter-N-Go ................. 37,317,414
Keyless Entry System ...................... 24
Keyless Go .......................... 14,317
Keys ................................. 14
Lap/Shoulder Belts ....................... 52
LATCH
(Lower Anchors and Tether for CHildren) .....85,86
Latches ................................ 98
Lead Free Gasoline ...................... 509
Leaks, Fluid ............................ 98
Life of Tires ............................ 494
Liftgate ................................ 44
Liftgate Flipper Glass ...................... 45
Liftgate Window Wiper/Washer ............. 274
664 INDEX

Supplemental Restraint System - Airbag........ 66
Suspension, Air ......................... 448
Sway Control, Trailer ..................... 470
Synthetic Engine Oil ...................... 581
System, Remote Starting .................... 29
Tachometer ............................ 285
Telescoping Steering Column .............194,195
Temperature Control, Automatic (ATC) ........ 398
Temperature Gauge, Engine Coolant .......... 294
Tether Anchor, Child Restraint ............... 85
Text Messaging ......................... 143
Tie Down Hooks, Cargo ................... 273
Tilt Steering Column ................... 194,195
Tire and Loading Information Placard ......... 483
Tire Identification Number (TIN) ............. 481
Tire Markings .......................... 477
Tire Safety Information .................... 477 Tires ............................
98,487,653
Air Pressure ........................ 488
Chains ............................ 496
Changing .......................... 549
Compact Spare ...................... 491
General Information .................. 487
High Speed ......................... 490
Inflation Pressures .................... 488
Jacking ............................ 549
Life of Tires ........................ 494
Load Capacity .................... 483,484
Pressure Monitor System (TPMS) ......... 499
Pressure Warning Light ................ 288
Quality Grading ..................... 653
Radial ............................ 490
Replacement ........................ 495
Rotation ........................... 498
Safety ............................. 477
Sizes ............................. 479
672 INDEX