2018 JEEP GRAND CHEROKEE wheel size

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 approximately one minute and then
remain continuously illuminated. This se-
quence will continue upon subsequent ve-
hicle 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 replace-
ment or alternate tires or wheels on the ve-
hicle that prevent the TPMS from functioning
properly. Always check the TPMS malfunc-
tion 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 opera-
tion 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.
Using aftermarket tire sealants may cause
the Tire Pressure Monitoring System
(TPMS) sensor to become inoperable. Af-
ter using an aftermarket tire sealant it is
recommended that you take your vehicle to
your authorized dealer to have your sensor
function checked.
Yellow Indicator Lights
— Air Suspension Light — If
Equipped
This light will illuminate when the air suspen-
sion system is actively adjusting the ride
height.
— Forward Collision Warning Off Indi-
cator Light — If Equipped
This light indicates that Forward Collision
Warning is off.
— 4WD Low Indicator Light — If
Equipped
This light alerts the driver that the vehicle is
in the four-wheel drive LOW mode. The front
and rear driveshafts are mechanically locked
together forcing the front and rear wheels to
rotate at the same speed. Low range provides
a greater gear reduction ratio to provide in-
creased torque at the wheels.
Refer to “Four-Wheel Drive Operation — If
Equipped” in “Starting And Operating” for
further information on four-wheel drive op-
eration and proper use.
— Rear Fog Indicator — If Equipped
This indicator light will illuminate when the
rear fog lights are on.
73

ESC uses sensors in the vehicle to determine
the vehicle path intended by the driver and
compares it to the actual path of the vehicle.
When the actual path does not match the
intended path, ESC applies the brake of the
appropriate wheel to assist in counteracting
the oversteer or understeer condition.
• Oversteer — when the vehicle is turning
more than appropriate for the steering
wheel position.
• Understeer — when the vehicle is turning
less than appropriate for the steering wheel
position.
The “ESC Activation/Malfunction Indicator
Light” located in the instrument cluster will
start to flash as soon as the ESC system
becomes active. The “ESC Activation/
Malfunction Indicator Light” also flashes
when the TCS is active. If the “ESC
Activation/Malfunction Indicator Light” be-
gins to flash during acceleration, ease up on
the accelerator and apply as little throttle as
possible. Be sure to adapt your speed and
driving to the prevailing road conditions.WARNING!
• Electronic Stability Control (ESC) can-
not prevent the natural laws of physics
from acting on the vehicle, nor can it
increase the traction afforded by prevail-
ing road conditions. ESC cannot prevent
accidents, including those resulting
from excessive speed in turns, driving on
very slippery surfaces, or hydroplaning.
ESC also cannot prevent accidents re-
sulting from loss of vehicle control due
to inappropriate driver input for the con-
ditions. Only a safe, attentive, and skill-
ful driver can prevent accidents. The
capabilities of an ESC equipped vehicle
must never be exploited in a reckless or
dangerous manner which could jeopar-
dize the user’s safety or the safety of
others.
• Vehicle modifications, or failure to prop-
erly maintain your vehicle, may change
the handling characteristics of your ve-
hicle, and may negatively affect the per-
formance of the ESC system. Changes to
the steering system, suspension, brak-
WARNING!
ing system, tire type and size or wheel
size may adversely affect ESC perfor-
mance. Improperly inflated and un-
evenly worn tires may also degrade ESC
performance. Any vehicle modification
or poor vehicle maintenance that re-
duces the effectiveness of the ESC sys-
tem can increase the risk of loss of
vehicle control, vehicle rollover, per-
sonal injury and death.
ESC Operating Modes
NOTE:
Depending upon model and mode of opera-
tion, the ESC system may have multiple op-
erating modes.
ESC On
This is the normal operating mode for the
ESC. Whenever the vehicle is started, the
ESC system will be in this mode. This mode
SAFETY
84

Monitoring Telltale Light will turn off only
after the tires have been inflated to the vehi-
cle’s recommended cold tire pressure value.
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 operation or sensor damage may
result when using replacement equip-
ment that is not of the same size, type,
and/or style. The TPM sensor is not de-
signed for use on aftermarket wheels
and may contribute to a poor overall
system performance or sensor damage.
Customers are encouraged to use OEM
wheels to assure proper TPM feature
operation.
• Using aftermarket tire sealants may
cause the Tire Pressure Monitoring Sys-
tem (TPMS) sensor to become inoper-
able. After using an aftermarket tire
sealant it is recommended that you take
CAUTION!
your vehicle to an authorized dealership
to have your sensor function checked.
• 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 Monitor-
ing Sensor.
NOTE:
• The TPMS is not intended to replace nor-
mal tire care and maintenance, or to pro-
vide 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.• The TPMS is not a substitute for proper tire
maintenance, and it is the driver’s respon-
sibility 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.
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.
SAFETY
96

WARNING!
air bags won’t deploy at all. Always wear
your seat belts even though you have air
bags.
Front Air Bag Operation
Front Air Bags are designed to provide addi-
tional protection by supplementing the seat
belts. Front air bags are not expected to
reduce the risk of injury in rear, side, or
rollover collisions. The front air bags will not
deploy in all frontal collisions, including
some that may produce substantial vehicle
damage — for example, some pole collisions,
truck underrides, and angle offset collisions.
On the other hand, depending on the type
and location of impact, front air bags may
deploy in crashes with little vehicle front-end
damage but that produce a severe initial
deceleration.
Because air bag sensors measure vehicle
deceleration over time, vehicle speed and
damage by themselves are not good indica-
tors of whether or not an air bag should have
deployed.Seat belts are necessary for your protection in
all collisions, and also are needed to help
keep you in position, away from an inflating
air bag.
When the ORC detects a collision requiring
the front air bags, it signals the inflator units.
A large quantity of non-toxic gas is generated
to inflate the front air bags.
The steering wheel hub trim cover and the
upper passenger side of the instrument panel
separate and fold out of the way as the air
bags inflate to their full size. The front air
bags fully inflate in less time than it takes to
blink your eyes. The front air bags then
quickly deflate while helping to restrain the
driver and front passenger.
Knee Impact Bolsters
The Knee Impact Bolsters help protect the
knees of the driver and front passenger, and
position the front occupants for improved
interaction with the front air bags.
WARNING!
• Do not drill, cut, or tamper with the knee
impact bolsters in any way.
• Do not mount any accessories to the
knee impact bolsters such as alarm
lights, stereos, citizen band radios, etc.
Supplemental Driver Knee Air Bag
This vehicle is equipped with a Supplemental
Driver Knee Air Bag mounted in the instru-
ment panel below the steering column. The
Supplemental Driver Knee Air Bag provides
enhanced protection during a frontal impact
by working together with the seat belts, pre-
tensioners, and front air bags.
Supplemental Side Air Bags
Supplemental Seat-Mounted Side Air Bags
(SABs) (If Equipped)
Your vehicle may be equipped with Supple-
mental Seat-Mounted Side Air Bags (SABs).
If your vehicle is equipped with Supplemen-
tal Seat-Mounted Side Air Bags (SABs),
please refer to the information below.
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112

WARNING!
inflate, even if they are in an infant or
child restraint.
• Seat belts (and child restraints where
appropriate) are necessary for your pro-
tection in all collisions. They also help
keep you in position, away from an in-
flating Side Air Bag. To get the best
protection from the Side Air Bags, occu-
pants must wear their seat belts properly
and sit upright with their backs against
the seats. Children must be properly
restrained in a child restraint or booster
seat that is appropriate for the size of the
child.
WARNING!
• Side Air Bags need room to inflate. Do
not lean against the door or window. Sit
upright in the center of the seat.
• Being too close to the Side Air Bags
during deployment could cause you to
be severely injured or killed.
• Relying on the Side Air Bags alone could
lead to more severe injuries in a colli-
WARNING!
sion. The Side Air Bags work with your
seat belt to restrain you properly. In
some collisions, Side Air Bags won’t
deploy at all. Always wear your seat belt
even though you have Side Air Bags.
NOTE:
Air bag covers may not be obvious in the
interior trim, but they will open during air bag
deployment.
Rollover Events (If Equipped With Rollover
Sensing)
Side Air Bags are designed to activate in
certain rollover events. The ORC determines
whether the deployment of the Side Air Bags
in a particular rollover event is appropriate,
based on the severity and type of collision.
Vehicle damage by itself is not a good indica-
tor of whether or not Side Air Bags should
have deployed.
The Side Air Bags will not deploy in all
rollover events. The rollover sensing system
determines if a rollover event may be in
progress and whether deployment is appro-priate. In the event the vehicle experiences a
rollover or near rollover event, and deploy-
ment of the Side Air Bags is appropriate, the
rollover sensing system will also deploy the
seat belt pretensioners on both sides of the
vehicle.
The SABICs may help reduce the risk of
partial or complete ejection of vehicle occu-
pants through side windows in certain roll-
over or side impact events.
Air Bag System Components
NOTE:
The Occupant Restraint Controller (ORC)
monitors the internal circuits and intercon-
necting wiring associated with electrical Air
Bag System Components listed below:
• Occupant Restraint Controller (ORC)
• Air Bag Warning Light
• Steering Wheel and Column
• Instrument Panel
• Knee Impact Bolsters
• Driver and Front Passenger Air Bags
• Seat Belt Buckle Switch
115

Quadra-Trac II Operating Instructions/
Precautions — If Equipped
The Quadra-Trac II transfer case is fully au-
tomatic in the normal driving 4WD AUTO
mode. The Quadra-Trac II transfer case pro-
vides three mode positions:
• 4WD HI
• NEUTRAL
• 4WD LOW
This transfer case is fully automatic in the
4WD HI mode.
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 in-
tended 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 dam-
age 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 or killed if
you leave the vehicle unattended with the
transfer case in the NEUTRAL position
without first fully engaging the parking
brake. The transfer case NEUTRAL posi-
tion disengages both the front and rear
drive shafts from the powertrain and will
allow the vehicle to roll, even if the trans-
mission is in PARK. The parking brake
WARNING!
should always be applied when the driver
is not in the vehicle.
Shift Positions
For additional information on the appropriate
use of each 4WD system 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” fur-
ther on in this section for further information
on the various positions and their intended
usages.
NEUTRAL
This range disengages the driveline from the
powertrain. It is to be used for flat towing
behind another vehicle. Refer to “Recre-
ational Towing” in “Starting And Operating”
for further information.
STARTING AND OPERATING
150

Replacement Tires
The tires on your new vehicle provide a bal-
ance of many characteristics. They should be
inspected regularly for wear and correct cold
tire inflation pressures. The manufacturer
strongly recommends that you use tires
equivalent to the originals in size, quality and
performance when replacement is needed.
Refer to the paragraph on “Tread Wear Indi-
cators” in this section. Refer to the Tire and
Loading Information placard or the Vehicle
Certification Label for the size designation of
your tire. The Load Index and Speed Symbol
for your tire will be found on the original
equipment tire sidewall.
It is recommended to replace the two front
tires or two rear tires as a pair. Replacing just
one tire can seriously affect your vehicle’s
handling. If you ever replace a wheel, make
sure that the wheel’s specifications match
those of the original wheels.
It is recommended you contact an authorized
tire dealer or original equipment dealer with
any questions you may have on tire specifica-tions or capability. Failure to use equivalent
replacement tires may adversely affect the
safety, handling, and ride of your vehicle.
WARNING!
• Do not use a tire, wheel size, load rating,
or speed rating other than that specified
for your vehicle. Some combinations of
unapproved tires and wheels may
change suspension dimensions and per-
formance characteristics, resulting in
changes to steering, handling, and brak-
ing of your vehicle. This can cause un-
predictable handling and stress to steer-
ing and suspension components. You
could lose control and have a collision
resulting in serious injury or death. Use
only the tire and wheel sizes with load
ratings approved for your vehicle.
• Never use a tire with a smaller load index
or capacity, other than what was origi-
nally equipped on your vehicle. Using a
tire with a smaller load index could re-
sult in tire overloading and failure. You
could lose control and have a collision.
WARNING!
• Failure to equip your vehicle with tires
having adequate speed capability can
result in sudden tire failure and loss of
vehicle control.
CAUTION!
Replacing original tires with tires of a
different size may result in false speedom-
eter and odometer readings.
Tire Types
All Season Tires — If Equipped
All Season tires provide traction for all sea-
sons (Spring, Summer, Fall, and Winter).
Traction levels may vary between different all
season tires. All season tires can be identified
by the M+S, M&S, M/S or MS designation on
the tire sidewall. Use all season tires only in
sets of four; failure to do so may adversely
affect the safety and handling of your vehicle.
259

Summer Or Three Season Tires — If
Equipped
Summer tires provide traction in both wet
and dry conditions, and are not intended to
be driven in snow or on ice. If your vehicle is
equipped with Summer tires, be aware these
tires are not designed for Winter or cold
driving conditions. Install Winter tires on your
vehicle when ambient temperatures are less
than 40°F (5°C) or if roads are covered with
ice or snow. For more information, contact an
authorized dealer.
Summer tires do not contain the all season
designation or mountain/snowflake symbol
on the tire sidewall. Use Summer tires only in
sets of four; failure to do so may adversely
affect the safety and handling of your vehicle.
WARNING!
Do not use Summer tires in snow/ice con-
ditions. You could lose vehicle control,
resulting in severe injury or death. Driving
too fast for conditions also creates the
possibility of loss of vehicle control.
Snow Tires
Some areas of the country require the use of
snow tires during the Winter. Snow tires can
be identified by a “mountain/snowflake”
symbol on the tire sidewall.
If you need snow tires,
select tires equivalent
in size and type to the
original equipment
tires. Use snow tires
only in sets of four;
failure to do so may
adversely affect the
safety and handling of your vehicle.
Snow tires generally have lower speed ratings
than what was originally equipped with your
vehicle and should not be operated at sus-
tained speeds over 75 mph (120 km/h). For
speeds above 75 mph (120 km/h) refer to
original equipment or an authorized tire
dealer for recommended safe operating
speeds, loading and cold tire inflation pres-
sures.While studded tires improve performance on
ice, skid and traction capability on wet or dry
surfaces may be poorer than that of non-
studded tires. Some states prohibit studded
tires; therefore, local laws should be checked
before using these tire types.
Spare Tires — If Equipped
For vehicles equipped with Tire Service Kit
instead of a spare tire, please refer to “Tire
Service Kit” in “In Case Of Emergency” in
the Owner’s Manual for further information.
CAUTION!
Because of the reduced ground clearance,
do not take your vehicle through an auto-
matic car wash with a compact or limited
use temporary spare installed. Damage to
the vehicle may result.
Spare Tire Matching Original Equipped Tire
And Wheel — If Equipped
Your vehicle may be equipped with a spare
tire and wheel equivalent in look and func-
tion to the original equipment tire and wheel
found on the front or rear axle of your vehicle.
SERVICING AND MAINTENANCE
260