2012 JEEP GRAND CHEROKEE tire size

Automatic Locking Retractor Mode
(ALR) — If Equipped
In this mode, the shoulder belt is automatically
pre-locked. The belt will still retract to remove
any slack in the shoulder belt. The Automatic
Locking Mode is available on all rear
passenger-seating positions with a combina-
tion lap/shoulder belt. Use the Automatic Lock-
ing Mode anytime a child safety seat is installed
in a seating position that has a belt with this
feature. Children 12 years old and under
should always be properly restrained in the rear
seat.
How To Engage The Automatic Locking
Mode
1. Buckle the combination lap and shoulder
belt.
2. Grasp the shoulder portion and pull down-
ward until the entire belt is extracted.
3. Allow the belt to retract. As the belt retracts,
you will hear a clicking sound. This indicates
the safety belt is now in the Automatic Locking
Mode.How To Disengage The Automatic Locking
Mode
Unbuckle the combination lap/shoulder belt
and allow it to retract completely to disengage
the Automatic Locking Mode and activate the
vehicle sensitive (emergency) locking mode.
WARNING!
•
The belt and retractor assembly must be
replaced if the seat belt assembly Auto-
matic Locking Retractor (ALR) feature or
any other seat belt function is not working
properly when checked according to the
procedures in the Service Manual.
• Failure to replace the belt and retractor
assembly could increase the risk of injury in
collisions.
Energy Management FeatureThis vehicle has a safety belt system with an
Energy Management feature in the front seating
positions to help further reduce the risk of injury
in the event of a head-on accident. This safety belt system has a retractor assem-
bly that is designed to release webbing in a
controlled manner. This feature is designed to
help reduce the belt force acting on the occu-
pant’s chest.
Seat Belt PretensionersThe seat belts for both front seating positions
are equipped with pretensioning devices that
are designed to remove slack from the seat belt
in the event of an accident. These devices may
improve the performance of the seat belt by
assuring that the belt is tight about the occu-
pant early in an accident. Pretensioners work
for all size occupants, including those in child
restraints.
NOTE:
These devices are not a substitute for
proper seat belt placement by the occupant.
The seat belt still must be worn snugly and
positioned properly.
The pretensioners are triggered by the Occu-
pant Restraint Controller (ORC). Like the air
bags, the pretensioners are single use items. A
deployed pretensioner or a deployed air bag
must be replaced immediately.
34

than 30 mph (48 km/h), see your authorized
dealer as soon as possible to have the problem
diagnosed and corrected.
NOTE:
•The “ESC Off Indicator Light” and the
“ESC Activation/Malfunction Indicator
Light” come on momentarily each time
the ignition switch is turned to ON/RUN.
• Each time the ignition is turned to ON/
RUN, the ESC system will be ON, even if it
was turned off previously.
• The ESC system will make buzzing or
clicking sounds when it is active. This is
normal; the sounds will stop when ESC
becomes inactive following the maneuver
that caused the ESC activation.
5. TOW/HAUL Indicator Light — If
Equipped This light will illuminate when the
TOW/HAUL button has been se-
lected. The TOW/HAUL button is
located in the center of the instru-
ment panel (below the climate
controls). 6. Turn Signal Indicator
The arrows will flash with the exterior turn
signals when the turn signal lever is op-
erated. A tone will chime, and an EVIC
message will appear if the turn signals are left
on for more than 1 mile (1.6 km).
NOTE:
Check for an inoperative outside light bulb if
either indicator flashes at a rapid rate.
7. High Beam Indicator Indicates that headlights are on high
beam.
8. Front Fog Light Indicator — If Equipped This indicator will illuminate when the
front fog lights are on.
9. Hill Descent Control Indicator Light — If
Equipped The symbol indicates the status of
the Hill Decent Control (HDC) fea-
ture. The lamp will be on solid
when HDC is armed. HDC can
only be armed when the transfer
case is in the “4WD Low” position and the vehicle speed is less then 30 mph
(48 km/h). If these conditions are not met while
attempting to use the HDC feature, the HDC
indicator lamp will flash on/off.
10. Electronic Vehicle Information Center
(EVIC) Display/Odometer Display
The odometer display shows the total distance
the vehicle has been driven.
When the appropriate conditions exist, this
display shows the Electronic Vehicle Informa-
tion Center (EVIC) messages. Refer to “Elec-
tronic Vehicle Information Center”.
11. Tire Pressure Monitoring Telltale Light
Each tire, including the spare (if
provided), should be checked
monthly when cold and inflated to
the inflation pressure recom-
mended by the vehicle manufac-
turer 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.)
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As an added safety feature, your vehicle has
been equipped with a Tire Pressure Monitoring
System (TPMS) that illuminates a low tire pres-
sure telltale when one or more of your tires is
significantly under-inflated. Accordingly, when
the low tire pressure telltale illuminates, you
should stop and check your tires as soon as
possible, and inflate them to the proper pres-
sure. 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.
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 TPMS low tire
pressure telltale.Your vehicle has also been equipped with a
TPMS malfunction indicator to indicate when
the system is not operating properly. The TPMS
malfunction indicator is combined with the low
tire pressure telltale. When the system detects
a malfunction, the telltale will flash for approxi-
mately one minute and then remain continu-
ously illuminated. This sequence will continue
upon subsequent vehicle start-ups as long as
the malfunction exists. When the malfunction
indicator is illuminated, the system may not be
able to detect or signal low tire pressure as
intended. TPMS malfunctions may occur for a
variety of reasons, including the installation of
replacement or alternate tires or wheels on the
vehicle that prevent the TPMS from functioning
properly. Always check the TPMS malfunction
telltale after replacing one or more tires or
wheels on your vehicle, to ensure that the
replacement or alternate tires and wheels allow
the TPMS to continue to function properly.CAUTION!
The TPMS has been optimized for the original
equipment tires and wheels. TPMS pressures
and warning have been established for the tire
size equipped on your vehicle. Undesirable
system operation or sensor damage may re-
sult 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 tire sealant from a can or
balance beads if your vehicle is equipped with
a TPMS, as damage to the sensors may
result.
12. Park/Headlight ON Indicator — If
Equipped This indicator will illuminate when
the park lights or headlights are
turned on.
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When additional traction is required, the 4WD
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 4WD LOW position is intended for loose,
slippery road surfaces only. Driving in the 4WD
LOW position on dry, hard-surfaced roads may
cause increased tire wear and damage to
driveline components.
When operating your vehicle in 4WD LOW, the
engine speed is approximately three times that
of the 4WD 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.WARNING!
You or others could be injured if you leave the
vehicle unattended with the transfer case in
the N (Neutral) position without first fully en-
gaging the parking brake. The transfer case N
(Neutral) position disengages both the front
and rear driveshafts from the powertrain and
will allow the vehicle to move regardless of the
transmission position. The parking brake
should always be applied when the driver is
not in the vehicle.
Shift Positions
For additional information on the appropriate
use of each transfer case mode position, see
the information below:
4WD AUTO
This range is used on surfaces such as ice,
snow, gravel, sand, and dry hard pavement.NOTE:
Refer to “Selec-Terrain
– If Equipped” in
“Starting and Operating” for further infor-
mation on the various positions and their
intended usages.
NEUTRAL
This range disengages both the front and rear
driveshafts from the powertrain. It is to be used
for flat towing behind another vehicle. Refer to
“Recreational Towing” in “Starting and Operat-
ing” for further information.
4WD LOW
This range is for low speed four-wheel drive. It
locks the front and rear driveshafts together
and forces the front and rear wheels to rotate at
the same speed. It provides additional traction
and maximum pulling power for loose, slippery
road surfaces only. Do not exceed 25 mph
(40 km/h).
NOTE:
Refer to “Selec-Terrain – If Equipped” for
further information on the various positions
and their intended usages.
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WARNING!
Fast spinning tires can be dangerous. Forces
generated by excessive wheel speeds may
cause tire damage or failure. A tire could
explode and injure someone. Do not spin your
vehicle’s wheels faster than 30 mph (48 km/h)
when you are stuck, and do not let anyone
near a spinning wheel, no matter what the
speed.
Tire ChainsUse of traction devices require sufficient tire-to-
body clearance. Follow these recommenda-
tions to guard against damage.
•Install on Rear Tires Only
• Due to limited clearance, use SAE class “S”
low profile cables or traction devices only.
Security Chain Company (SCC) Super Z6
#SZ 441 cables or equivalent are recom-
mended.
WARNING!
Using tires of different size and type (M+S,
Snow) between front and rear axles can
cause unpredictable handling. You could lose
control and have a collision.
CAUTION!
To avoid damage to your vehicle or tires,
observe the following precautions:
• Because of restricted traction device clear-
ance between tires and other suspension
components, it is important that only trac-
tion devices in good condition are used.
Broken devices can cause serious dam-
age. Stop the vehicle immediately if noise
occurs that could indicate device breakage.
Remove the damaged parts of the device
before further use.
• Install device as tightly as possible and
then retighten after driving about 0.5 mile
(0.8 km).
• Do not exceed 30 mph (48 km/h).
(Continued)
CAUTION!(Continued)
• Drive cautiously and avoid severe turns
and large bumps, especially with a loaded
vehicle.
• Do not drive for prolonged period on dry
pavement.
• Observe the traction device manufacturer’s
instructions on the method of installation,
operating speed, and conditions for use.
Always use the suggested operating speed
of the device manufacturer’s if it is less than
30 mph (48 km/h).
• Do not use traction devices on a compact
spare tire.
Treadwear IndicatorsThese indicators are narrow strips 1/16 in
(1.6 mm) thick and are found in the tread
pattern grooves.
When the tread pattern is worn down to these
treadwear indicators, the tires should be re-
placed.
254

Overloading your vehicle, long trips in very hot
weather, and driving on bad roads may result in
greater wear.
Life Of TireThe service life of a tire is dependent upon
varying factors including but not limited to:
•Driving style
• Tire pressure
• Distance driven
WARNING!
Tires and the spare tire 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 or death.
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 TiresThe tires on your new vehicle provide a balance
of many characteristics. They should be in-
spected regularly for wear and correct inflation
pressure. The manufacturer strongly recom-
mends that you use tires equivalent to the
originals in quality and performance when re-
placement is needed (see section on tread
wear indicators). Failure to use equivalent re-
placement tires may adversely affect the safety,
handling and ride of your vehicle. We recom-
mend that you contact your local authorized
dealer on any questions you may have on tire
specifications or capability.
WARNING!
• Do not use a tire, wheel size or rating other
than that specified for your vehicle. Some
combinations of unapproved tires and
wheels may change suspension dimen-
sions and performance characteristics, re-
sulting in changes to steering, handling,
and stress to steering and suspension
components. You could lose control and
have an accident resulting in serious injury
or death. Use only the tire and wheel sizes
with load ratings approved for your vehicle.
• Never use a tire smaller than the minimum
tire size listed on your vehicle’s tire placard
unless explicitly instructed to do so by the
vehicle manufacturer (reference tire chain
information in this manual). Using an
under-sized tire could result in tire over-
loading and failure.
•
Failure to equip your vehicle with tires having
adequate speed capability can result in sud-
den tire failure and loss of vehicle control.
(Continued)
1—WornTire
2 — New Tire
255

WARNING!(Continued)
• Overloading your tires is dangerous. Like
under-inflation, overloading can cause tire
failure. Use tires of the recommended load
capacity for your vehicle — never overload
them.
CAUTION!
Replacing original tires with tires of a different
size may result in false speedometer and
odometer readings. This can also affect ve-
hicle performance and can do potential dam-
age to the driveline. Check with your dealer
before replacing tires with a different size.
Directional Tread Pattern Tires – If
Equipped
Your vehicle may be equipped with tires using
a directional tread pattern. These tires are
designed to optimize dry handling as well as
wet performance. To obtain the full benefits of
this design, the tires must be installed so that
they rotate in the correct direction. The rotation
direction of this type of tire is indicated by arrows on the side wall of the tire. The full size
spare tire is mounted as a direct replacement
for the right side of the vehicle. For a flat tire on
the left side of the vehicle, the full size spare
can be used as mounted. If this is required,
correct the rotation as soon as possible to
restore optimum wet performance.
TIRE ROTATION
RECOMMENDATIONS
Non-Directional Tires Only
Tires on the front and rear axles of vehicles
operate at different loads and perform different
steering, handling, and braking functions. For
these reasons, they wear at unequal rates.
These effects can be reduced by timely rotation
of tires. The benefits of rotation are especially
worthwhile with aggressive tread designs such
as those on On/Off-Road type tires. Rotation
will increase tread life, help to maintain mud,
snow, and wet traction levels, and contribute to
a smooth, quiet ride.
Refer to the “Maintenance Schedule” for the
proper maintenance intervals. More frequent
rotation is permissible if desired. The reasons
for any rapid or unusual wear should be cor-
rected prior to rotation being performed.
NOTE:
The premium Tire Pressure Monitor System
will automatically locate the pressure values
displayed in the correct vehicle position
following a tire rotation.
The suggested rotation method is the “forward-
cross” shown in the following diagram.
Tire Rotation
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TIRE PRESSURE MONITOR SYSTEM
(TPMS)
The Tire Pressure Monitoring System (TPMS)
will warn the driver of a low tire pressure based
on the vehicle recommended cold tire pressure.
The tire pressure will vary with temperature by
about 1 psi (7 kPa) for every 12°F (6.5°C). This
means that when the outside temperature de-
creases, 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 Information” 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 pressure. Once
the “TPM Telltale Light” and the “TIRE LOW
PRESSURE” message appears, the tire pres-
sure must be increased to the recommended
cold tire pressure in order for the ”TPM Telltale
Light” and the “TIRE LOW PRESSURE” mes-
sage to be turned off. The system will automati-
cally update and the “TPM Telltale Light” and
the “TIRE LOW PRESSURE” message will turn
off 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
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 pres-
sure to approximately 24 psi (165 kPa). This tire
pressure is sufficiently low enough to display
the “TPM Telltale Light” and the “TIRE LOW
PRESSURE” message. Driving the vehicle maycause the tire pressure to rise to approximately
28 psi (193 kPa), but the “TPM Telltale Light”
and the “TIRE LOW PRESSURE” message will
still display. In this situation, the “TPM Telltale
Light” and the “TIRE LOW PRESSURE” mes-
sage 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. Unde-
sirable system operation or sensor damage
may result when using replacement equip-
ment that is not of the same size, type,
and/or style. Aftermarket wheels can cause
sensor damage. 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)
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