2007 JEEP GRAND CHEROKEE tire size

12. Tire Pressure Monitoring Telltale Light
Each tire, including the spare (if provided),
should be checked monthly when cold and
inflated to the inflation pressure recommended
by the vehicle manufacturer on the vehicle
placard or tire inflation pressure label. (If your vehicle
has tires of a different size than the size indicated on the
vehicle placard or tire inflation pressure label, you should
determine the proper tire inflation pressure for those
tires.)
As an added safety feature, your vehicle has been
equipped with a tire pressure monitoring system (TPMS)
that illuminates a “Tire Pressure Monitoring Telltale
Light” when one or more of your tires is significantly
under-inflated. Accordingly, when the “Tire Pressure
Monitoring Telltale Light” illuminates, you should stop
and check your tires as soon as possible, and inflate them
to the proper pressure. Driving on a significantly under-
inflated tire causes the tire to overheat and can lead to tirefailure. Under-inflation also reduces fuel efficiency and
tire tread life, and may affect the vehicle’s handling and
stopping ability.
Please note that the TPMS is not a substitute for proper
tire maintenance, and it is the driver ’s responsibility to
maintain correct tire pressure, even if under-inflation has
not reached the level to trigger illumination of the “Tire
Pressure Monitoring Telltale Light.”
The “Tire Pressure Monitoring Telltale Light” will illumi-
nate in the instrument cluster, and an audible chime will
be activated when one or more tire pressures is low. The
“Tire Pressure Monitoring Telltale Light” will flash on
and off for 60 seconds when a system fault is detected.
The flash cycle will repeat every ten minutes or until the
fault condition is removed and reset.
178 UNDERSTANDING YOUR INSTRUMENT PANEL

CAUTION!
The TPMS has been optimized for the original
equipment tires and wheels. TPMS pressures and
warnings have been established for the tire size
equipped on your vehicle. Undesirable system op-
eration or sensor damage may result when using
replacement equipment that is not of the same size,
type, and/or style. After-market wheels can cause
sensor damage. Do not use tire sealant from a can, or
balance beads if your vehicle is equipped with a
TPMS, as damage to the sensors may result.
13. Temperature Gauge
The temperature gauge shows engine coolant tempera-
ture. Any reading within the normal range indicates that
the engine cooling system is operating satisfactorily.The gauge pointer will likely indicate a higher tempera-
ture when driving in hot weather, up mountain grades,
or when towing a trailer. It should not be allowed to
exceed the upper limits of the normal operating range.
CAUTION!
Driving with a hot engine cooling system could
damage your vehicle. If temperature gauge reads (H),
pull over and stop the vehicle. Idle the vehicle with
the air conditioner turned off until the pointer drops
back into the normal range. If the pointer remains on
the “H”, and you hear continuous chimes, turn the
engine off immediately, and call for service.
UNDERSTANDING YOUR INSTRUMENT PANEL 179
4

percent of engine torque to the rear axle. When speed
differences are increased between the front and rear drive
shafts, the transfer case can transmit up to 100 percent of
available engine torque to the front or rear drive shafts.
When additional traction is required, the 4 LOW position
can be used to lock the front and rear driveshafts together
and force the front and rear wheels to rotate at the same
speed. The 4 LOW position is intended for loose, slippery
road surfaces only. Driving in the 4 LOW position on dry
hard surfaced roads may cause increased tire wear and
damage to driveline components.
When operating your vehicle in 4 LOW, the engine speed
is approximately three times that of the 4 HI position at a
given road speed. Take care not to overspeed the engine
and do not exceed 25 mph (40 km/h).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.
Because four wheel drive provides improved traction,
there is a tendency to exceed safe turning and stopping
speeds. Do not go faster than road conditions permit.
STARTING AND OPERATING 263
5

When parking on a hill, turn the front wheels toward the
curb on a downhill grade and away from the curb on an
uphill grade.
The parking brake should always be applied whenever
the driver is not in the vehicle.
ANTI-LOCK BRAKE SYSTEM
The Anti-Lock Brake System (ABS) is designed to aid the
driver in maintaining vehicle control under adverse
braking conditions. The system operates with a separate
computer to modulate hydraulic pressure to prevent
wheel lock-up and help avoid skidding on slippery
surfaces.
All vehicle wheels and tires must be the same size and
type and tires must be properly inflated to produce
accurate signals for the computer.
WARNING!
Significant over or under inflation of tires, or mixing
sizes of tires or wheels on the vehicle can lead to loss
of braking effectiveness.
The Anti-Lock Brake System conducts a low-speed self-
test at about 12 mph (20 km/h). If you have your foot
lightly on the brake while this test is occurring you may
feel slight pedal movement. The movement can be more
apparent on ice and snow. This is normal.
The Anti-Lock Brake System pump motor runs during
the self-test at 12 mph (20 km/h) and during an ABS stop.
The pump motor makes a low humming noise during
operation, which is normal.
274 STARTING AND OPERATING

CAUTION!
Prolonged operation of the steering system at the
end of the steering wheel travel will increase the
steering fluid temperature and it should be avoided
when possible. Damage to the power steering pump
may occur.
MULTI DISPLACEMENT SYSTEM (MDS) - 5.7L
Engine Only
This feature offers improved fuel economy by shutting
off four of the engine’s eight cylinders during light load
and cruise conditions. The system is automatic with no
driver inputs or additional driving skills required.
NOTE:The MDS system may take some time to return
to full functionality after a battery disconnect.
TIRE SAFETY INFORMATION
Tire Markings
NOTE:
•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. Ex-
ample: P215/65R15 95H.
278 STARTING AND OPERATING

•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 letterPis 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 preced-
ing the size designation. Example: LT235/85R16.
•Temporary Spare tires are high-pressure compact
spares designed for temporary emergency use only.
Tires designed to this standard have the letter “T”
molded into the sidewall preceding the size designa-
tion. Example: T145/80D18 103M.
•High Flotation tire sizing is based on U.S. design
standards and it begins with the tire diameter molded
into the sidewall. Example: 31x10.5 R15 LT.
STARTING AND OPERATING 279
5

Tire Sizing Chart
EXAMPLE:
Size Designation:
P= Passenger car tire size based on U.S. design standards
....blank....= Passenger car tire based on European design standards
LT= Light Truck tire based on U.S. design standards
T= Temporary Spare tire
31= Overall Diameter in Inches (in)
215= Section Width in Millimeters (mm)
65= Aspect Ratio in Percent (%)
—Ratio of section height to section width of tire.
10.5= Section Width in Inches (in)
R= Construction Code
—Rmeans Radial Construction.
—Dmeans Diagonal or Bias Construction.
15= Rim Diameter in Inches (in)
280 STARTING AND OPERATING

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
date code located on the white sidewall side of the tire.Look for the 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. (2 digits)
L9= Code representing the tire size. (2 digits)
ABCD= Code used by tire manufacturer. (1 to 4 digits)
03= Number representing the week in which the tire was manufactured. (2 digits)
—03 means the 3rd week.
01= Number representing the year in which the tire was manufactured. (2 digits)
—01 means the year 2001.
—Prior to July 2000, tire manufacturers were only required to have 1 number to represent the year in
which the tire was manufactured. Example: 031 could represent the 3rd week of 1981 or 1991.
282 STARTING AND OPERATING