2010 JEEP GRAND CHEROKEE tire pressure

Safety
WARNING!
•Improperly inflated tires are dangerous and can
cause accidents.
•Under inflation increases tire flexing and can
result in over-heating and tire failure.
•Over inflation reduces a tire’s ability to cushion
shock. Objects on the road and chuck holes can
cause damage that results in tire failure.
•Unequal tire pressures can cause steering prob-
lems. You could lose control of your vehicle.
•Overinflated or under inflated tires can affect
vehicle handling and can fail suddenly, resulting
in loss of vehicle control.
•Unequal tire pressures from one side of the ve-
hicle to the other can cause the vehicle to drift to
the right or left.
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
consumption.
Ride Comfort and Vehicle Stability
Proper tire inflation contributes to a comfortable ride.
Over inflation produces a jarring and uncomfortable ride.
Both under inflation and over inflation affect the stability
of the vehicle and can produce a feeling of sluggish
response or over responsiveness in the steering.
Unequal tire pressures can cause erratic and unpredict-
able steering response.
Unequal tire pressure from side to side may cause the
vehicle to drift left or right.5
STARTING AND OPERATING 273

Tire Inflation Pressures
The proper cold tire inflation pressure is listed on the
driver’s side “B” Pillar.
The pressure should be checked and adjusted as well as
inspecting for signs of tire wear or visible damage at least
once a month. Use a good quality pocket-type gauge to
check tire pressure. Do not make a visual judgement
when determining proper inflation. Radial tires may look
properly inflated even when they are under inflated.
CAUTION!
After inspecting or adjusting the tire pressure always
reinstall the valve stem cap. This will prevent mois-
ture and dirt from entering the valve stem, which
could damage the valve stem.
Inflation pressures specified on the placard are always
“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 a three hour period. The cold tire
inflation pressure must not exceed the maximum infla-
tion pressure molded into the tire side wall.
Check tire pressures more often if subject to a wide range
of outdoor temperatures, as tire pressures vary with
temperature changes.
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.
274 STARTING AND OPERATING

Tire pressure may increase from 2 to 6 psi (13 to 40 kPa)
during operation. DO NOT reduce this normal pressure
build up 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 vehicle
loading 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.
WARNING!
High speed driving with your vehicle under maxi-
mum load is dangerous. The added strain on your
tires could cause them to fail. You could have a
serious accident. Do not drive a vehicle loaded to the
maximum capacity at continuous speeds above
75 mph (120 km/h).
Radial-Ply Tires
WARNING!
Combining radial ply tires with other types of tires
on your vehicle will cause your vehicle to handle
poorly. The instability could cause an accident. Al-
ways use radial tires in sets of four. Never combine
them with other types of tires.
5
STARTING AND OPERATING 275

These indicators are molded into the bottom of the tread
grooves. They will appear as bands when the tread depth
becomes 1/16 in (2 mm). When the tread is worn to the
tread wear indicators, the tire should be replaced.
Life of Tire
The service life of a tire is dependent upon varying
factors including but not limited to:
•Driving style
•Tire pressure
•Distance driven
WARNING!
All tires should be replaced after six years, regardless
of the remaining tread. Failure to follow this warning
can result in sudden tire failure. You could lose control
and have an accident resulting in serious injury.
Keep unmounted tires in a cool, dry place with as little
exposure to light as possible. Protect tires from contact
with oil, grease and gasoline.
Replacement Tires
The tires on your new vehicle provide a balance of many
characteristics. They should be inspected regularly for
wear and correct cold tire inflation pressure. The manu-
facturer strongly recommends that you use tires equiva-
lent to the originals in size, quality and performance
when replacement is needed (see the paragraph on tread
wear indicators). Refer to the Tire and Loading Informa-
tion placard for the size designation of your tire. The
service description and load identification will be found
on the original equipment tire. Failure to use equivalent
replacement tires may adversely affect the safety, han-
dling, and ride of your vehicle. We recommend that you
contact your original equipment or an authorized tire
dealer with any questions you may have on tire specifi-
cations or capability.
5
STARTING AND OPERATING 277

TIRE PRESSURE MONITOR SYSTEM (TPMS)
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 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
•4 Tire Pressure Monitoring Sensors
•3 Trigger Modules (mounted in three of the four wheel
wells)
•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
Electronic Vehicle Information Center (EVIC) will display
one or more Low Pressure messages (Left Front, Left
Rear, Right Front, Right Rear) for three seconds, and a
graphic display of the pressure value(s) with the low
tire(s) flashing. Refer to “Electronic Vehicle Information
Center (EVIC)” in “Understanding Your Instrument
Panel” for further information.
5
STARTING AND OPERATING 279

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.
Check TPM System Message
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 “CHECK TPM SYS-
TEM” message for three seconds. This text 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.
NOTE:
Your system can be set to display pressure units
in PSI, kPa, or BAR.
280 STARTING AND OPERATING

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, theCHECK TPM SYSTEM
text message will not be present, and a pressure value
will be displayed instead of dashes. 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.
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.
5
STARTING AND OPERATING 281

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 ..................... KR5S120123
Canada ........................ 2671-S120123
FUEL REQUIREMENTS
6.1L Engine
The 6.1L 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.
282 STARTING AND OPERATING