2018 JEEP GRAND CHEROKEE inflation pressure

SERV4WD— Service 4WD Warning Light — If
Equipped
If the light stays on or comes on during
driving, it means that the 4WD system is not
functioning properly and that service is re-
quired. We recommend you drive to the near-
est service center and have the vehicle ser-
viced immediately.
— Service Forward Collision Warning
(FCW) Light — If Equipped
This telltale will turn on to indicate a fault in
the Forward Collision Warning System. Con-
tact your local authorized dealer for service.
Refer to "Forward Collision Warning (FCW)" in
"Safety" for further information.
— Service Stop/Start System Warning
Light — If Equipped
This telltale will turn on to indicate the Stop/
Start system is not functioning properly and
service is required. Contact your authorized
dealer for service.
— Tire Pressure Monitoring System
(TPMS) Warning Light
The warning light switches on and a message
is displayed to indicate that the tire pressure
is lower than the recommended value and/or
that slow pressure loss is occurring. In these
cases, optimal tire duration and fuel con-
sumption may not be guaranteed.
Should one or more tires be in the condition
mentioned above, the display will show the
indications corresponding to each tire in
sequence.
CAUTION!
Do not continue driving with one or more
flat tires as handling may be compro-
mised. Stop the vehicle, avoiding sharp
braking and steering. If a tire puncture
occurs, repair immediately using the dedi-
cated tire repair kit and contact your au-
thorized dealer as soon as possible.
Each tire, including the spare (if provided),
should be checked monthly when cold and
inflated to the inflation pressure recom-
mended by the vehicle manufacturer on thevehicle placard or tire inflation pressure la-
bel. (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 monitor-
ing system (TPMS) that illuminates a low tire
pressure telltale when one or more of your
tires is significantly under-inflated. Accord-
ingly, when the low tire pressure telltale illu-
minates, 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 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.
GETTING TO KNOW YOUR INSTRUMENT PANEL
72

Tire Pressure Monitor System (TPMS)
NOTE:
For vehicles equipped with run flat tires —
when the TPMS indicates a tire pressure of
14 psi (96 kPa) or lower, always check tire
pressure and replace the tire at the first
opportunity. At inflation pressure of/or below
14 psi (96 kPa) the tire is in the run-flat
mode of operation. In this condition, it is
recommended a vehicle maximum speed of
50 mph (80 km/h) for a maximum distance of
50 miles (80 km). The manufacturer does not
recommend using the run flat feature while
driving a vehicle loaded at full capacity or
towing a trailer.
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 tempera-
ture decreases, the tire pressure will de-
crease. Tire pressure should always be set
based on cold inflation tire pressure. This is
defined as the tire pressure after the vehiclehas 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” in “Servic-
ing And Maintenance” 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 rea-
son, 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 low tire pressure
warning has been illuminated, the tire pres-
sure must be increased to the recommended
cold tire pressure in order for the Tire Pres-
sure Monitoring Telltale Light to be turned
off.NOTE:
When filling warm tires, the tire pressure may
need to be increased up to an additional 4 psi
(28 kPa) above the recommended cold plac-
ard pressure in order to turn the Tire Pressure
Monitoring Telltale Light 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 10 minutes above 15 mph
(24 km/h) to receive this information.
For example, your vehicle has a recom-
mended 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 pressure to approxi-
mately 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 Light will
still be on. In this situation, the Tire Pressure
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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!
clutch pedal (if present) to check for
interference. If your floor mat interferes
with the operation of any pedal, or is not
secure to the floor, remove the floor mat
from the vehicle and place the floor mat
in your trunk.
• ONLY use the passenger’s side floor mat
on the passenger’s side floor area.
• ALWAYS make sure objects cannot fall
or slide into the driver’s side floor area
when the vehicle is moving. Objects can
become trapped under accelerator,
brake, or clutch pedals and could cause
a loss of vehicle control.
• NEVER place any objects under the floor
mat (e.g., towels, keys, etc.). These ob-
jects could change the position of the
floor mat and may cause interference
with the accelerator, brake, or clutch
pedals.
• If the vehicle carpet has been removed
and re-installed, always properly attach
WARNING!
carpet to the floor and check the floor
mat fasteners are secure to the vehicle
carpet. Fully depress each pedal to
check for interference with the accelera-
tor, brake, or clutch pedals then re-
install the floor mats.
• It is recommended to only use mild soap
and water to clean your floor mats. After
cleaning, always check your floor mat
has been properly installed and is se-
cured to your vehicle using the floor mat
fasteners by lightly pulling mat.
Periodic Safety Checks You Should Make
Outside The Vehicle
Tires
Examine tires for excessive tread wear and
uneven wear patterns. Check for stones,
nails, glass, or other objects lodged in the
tread or sidewall. Inspect the tread for cuts
and cracks. Inspect sidewalls for cuts,cracks, and bulges. Check the wheel nuts for
tightness. Check the tires (including spare)
for proper cold inflation pressure.
Lights
Have someone observe the operation of brake
lights and exterior lights while you work the
controls. Check turn signal and high beam
indicator lights on the instrument panel.
Door Latches
Check for proper closing, latching, and lock-
ing.
Fluid Leaks
Check area under the vehicle after overnight
parking for fuel, coolant, oil, or other fluid
leaks. Also, if gasoline fumes are detected or
if fuel, or brake fluid leaks are suspected. The
cause should be located and corrected
immediately.
133

WARNING!
had time to cool. Never open a cooling
system pressure cap when the radiator
or coolant bottle is hot.
• Keep hands, tools, clothing, and jewelry
away from the radiator cooling fan when
the hood is raised. The fan starts auto-
matically and may start at any time,
whether the engine is running or not.
• When working near the radiator cooling
fan, disconnect the fan motor lead or
turn the ignition to the OFF mode. The
fan is temperature controlled and can
start at any time the ignition is in the ON
mode.
Engine Coolant Checks
Check the engine coolant (antifreeze) protec-
tion every 12 months (before the onset of
freezing weather, where applicable). If the
engine coolant (antifreeze) is dirty, the sys-
tem should be drained, flushed, and refilled
with fresh OAT coolant (conforming to
MS.90032) by an authorized dealer. Check
the front of the A/C condenser for any accu-mulation of bugs, leaves, etc. If dirty, clean
by gently spraying water from a garden hose
vertically down the face of the condenser.
Check the engine cooling system hoses for
brittle rubber, cracking, tears, cuts, and
tightness of the connection at the coolant
recovery bottle and radiator. Inspect the en-
tire system for leaks. DO NOT REMOVE THE
COOLANT PRESSURE CAP WHEN THE
COOLING SYSTEM IS HOT.
RAISING THE VEHICLE
In the case where it is necessary to raise the
vehicle, go to an authorized dealer or service
station.
TIRES
Tires — General Information
Tire Pressure
Proper tire inflation pressure is essential to
the safe and satisfactory operation of your
vehicle. Four primary areas are affected by
improper tire pressure:
• Safety and Vehicle Stability• Economy
• Tread Wear
• Ride Comfort
Safety
WARNING!
• Improperly inflated tires are dangerous
and can cause collisions.
• Underinflation increases tire flexing and
can result in overheating and tire failure.
• Overinflation reduces a tire's ability to
cushion shock. Objects on the road and
chuckholes can cause damage that re-
sult in tire failure.
• Overinflated or underinflated tires can
affect vehicle handling and can fail sud-
denly, resulting in loss of vehicle control.
• Unequal tire pressures can cause steer-
ing problems. You could lose control of
your vehicle.
• Unequal tire pressures from one side of
the vehicle to the other can cause the
vehicle to drift to the right or left.
255

WARNING!
• Always drive with each tire inflated to
the recommended cold tire inflation
pressure.
Both under-inflation and over-inflation affect
the stability of the vehicle and can produce a
feeling of sluggish response or over respon-
siveness in the steering.
NOTE:
• Unequal tire pressures from side to side
may cause erratic and unpredictable steer-
ing response.
• Unequal tire pressure from side to side may
cause the vehicle to drift left or right.
Fuel Economy
Underinflated tires will increase tire rolling
resistance resulting in higher fuel consump-
tion.
Tread Wear
Improper cold tire inflation pressures can
cause abnormal wear patterns and reduced
tread life, resulting in the need for earlier tire
replacement.Ride Comfort And Vehicle Stability
Proper tire inflation contributes to a comfort-
able ride. Over-inflation produces a jarring
and uncomfortable ride.
Tire Inflation Pressures
The proper cold tire inflation pressure is
listed on the left side B-Pillar or rear edge of
the passenger door.
At least once a month:
• Check and adjust tire pressure with a good
quality pocket-type pressure gauge. Do not
make a visual judgement when determining
proper inflation. Tires may look properly
inflated even when they are under-inflated.
• Inspect tires for signs of tire wear or visible
damage.
CAUTION!
After inspecting or adjusting the tire pres-
sure, always reinstall the valve stem cap.
This will prevent moisture and dirt from
entering the valve stem, which could dam-
age 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 sitting for a minimum of
three hours. The cold tire inflation pressure
must not exceed the maximum inflation pres-
sure molded into the tire sidewall.
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.
SERVICING AND MAINTENANCE
256

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 and within posted speed limits. Where
speed limits or conditions are such that the
vehicle can be driven at high speeds, maintain-
ing correct tire inflation pressure is very impor-
tant. Increased tire pressure and reduced ve-
hicle loading may be required for high-speed
vehicle operation. Refer to an authorized tire
dealer or original equipment vehicle dealer for
recommended safe operating speeds, loading
and cold tire inflation pressures.
WARNING!
High speed driving with your vehicle under
maximum load is dangerous. The added
strain on your tires could cause them to
fail. You could have a serious collision. 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 a collision. Always use radial
ply tires in sets of four. Never combine
them with other types of tires.
Tire Repair
If your tire becomes damaged, it may be
repaired if it meets the following criteria:
• The tire has not been driven on when flat.
• The damage is only on the tread section of
your tire (sidewall damage is not repair-
able).
• The puncture is no greater thana¼ofan
inch (6 mm).
Consult an authorized tire dealer for tire re-
pairs and additional information.Damaged Run Flat tires, or Run Flat tires that
have experienced a loss of pressure should be
replaced immediately with another Run Flat
tire of identical size and service description
(Load Index and Speed Symbol).
Run Flat Tires — If Equipped
Run Flat tires allow you the capability to drive
50 miles (80 km) at 50 mph (80 km/h) after
a rapid loss of inflation pressure. This rapid
loss of inflation is referred to as the Run Flat
mode. A Run Flat mode occurs when the tire
inflation pressure is of/or below 14 psi
(96 kPa). Once a Run Flat tire reaches the
run flat mode it has limited driving capabili-
ties and needs to be replaced immediately. A
Run Flat tire is not repairable.
It is not recommended driving a vehicle
loaded at full capacity or to tow a trailer while
a tire is in the run flat mode.
See the tire pressure monitoring section for
more information.
257

Tire Spinning
When stuck in mud, sand, snow, or ice con-
ditions, do not spin your vehicle's wheels
above 30 mph (48 km/h) or for longer than
30 seconds continuously without stopping.
Refer to “Freeing A Stuck Vehicle” in “In
Case Of Emergency” for further information.
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) for more than 30 sec-
onds continuously when you are stuck,
and do not let anyone near a spinning
wheel, no matter what the speed.
Tread Wear Indicators
Tread wear indicators are in the original
equipment tires to help you in determining
when your tires should be replaced.These indicators are molded into the bottom
of the tread grooves. They will appear as
bands when the tread depth becomes a
1/16 of an inch (1.6 mm). When the tread is
worn to the tread wear indicators, the tire
should be replaced. Refer to “Replacement
Tires” in this section for further information.
Life Of Tire
The service life of a tire is dependent upon
varying factors including, but not limited to:
• Driving style.
• Tire pressure - Improper cold tire inflation
pressures can cause uneven wear patterns
to develop across the tire tread. These ab-normal wear patterns will reduce tread life,
resulting in the need for earlier tire replace-
ment.
• Distance driven.
• Performance tires, tires with a speed rating
of V or higher, and Summer tires typically
have a reduced tread life. Rotation of these
tires per the vehicle scheduled mainte-
nance is highly recommended.
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 a collision resulting in
serious injury or death.
Keep dismounted tires in a cool, dry place
with as little exposure to light as possible.
Protect tires from contact with oil, grease,
and gasoline.
Tire Tread
1 — Worn Tire
2 — New Tire
SERVICING AND MAINTENANCE
258