2018 JEEP WRANGLER UNLIMITED cooling

Climate Control Functions
Air Conditioning (A/C)
The Air Conditioning (A/C) button allows the
operator to turn the air conditioning system
on and off. When the system is turned on,
cool dehumidified air flows through the vents
into the cabin.
For improved fuel economy, press the A/C
button to turn off the air conditioning off and
adjust the blower and airflow mode settings.
Make sure to only select Panel, Bi-Level, or
Floor modes.
NOTE:
• If fog or mist appears on the windshield or
windows, select Defrost mode and increase
the blower speed.
• If the air conditioning performance is lower
than expected, there maybe blockage. Gen-
tly clean the area around the radiator with
water.
MAX A/C
The MAX A/C setting provides the maximum
cooling performance.Press the button to toggle between MAX A/C
and your prior setting. The button illuminates
when MAX A/C is on.
In the MAX A/C setting, you can adjust the
blower level and mode position. Pressing
other settings causes the MAX A/C operation
to switch to your desired setting.
Recirculation
In cold weather, use of Recirculation mode
may lead to excessive window fogging. The
Recirculation feature may be unavailable
(button on the touchscreen greyed out) if
conditions exist that could create fogging on
the inside of the windshield.
Automatic Temperature Control (ATC) —
If Equipped
Automatic Operation
1. Push the AUTO button on the faceplate,
or the AUTO button on the touchscreen on
the Automatic Temperature Control (ATC)
Panel.
2. Next, adjust the temperature you would
like the system to maintain by adjusting
the driver and passenger temperaturecontrol buttons. Once the desired tem-
perature is displayed, the system will
achieve and automatically maintain that
comfort level.
3. When the system is set up for your comfort
level, it is not necessary to change the
settings. You will experience the greatest
efficiency by simply allowing the system
to function automatically.
NOTE:
• It is not necessary to move the temperature
settings for cold or hot vehicles. The system
automatically adjusts the temperature,
mode, and blower speed to provide comfort
as quickly as possible.
• The temperature can be displayed in U.S.
or Metric units by selecting the US/Metric
customer-programmable feature. Refer to
the “Uconnect Settings” in “Multimedia”
in your Owner’s Manual for further
information.
To provide you with maximum comfort in the
Automatic mode during cold start-ups, the
blower fan will remain on low until the engine
warms up. The blower will increase in speed
and transition into Auto mode.
GETTING TO KNOW YOUR VEHICLE
44

Manual Operation Override
This system offers a full complement of
manual override features. The AUTO symbol
in the front ATC display will be turned off
when the system is being used in the manual
mode.
Operating Tips
Summer Operation
The engine cooling system must be protected
with a high-quality antifreeze coolant to pro-
vide proper corrosion protection and to pro-
tect against engine overheating. OAT coolant
(conforming to MS.90032) is recommended.
Winter Operation
To ensure the best possible heater and de-
froster performance, make sure the engine
cooling system is functioning properly and
the proper amount, type, and concentration
of coolant is used. Use of the Air Recircula-
tion mode during Winter months is not rec-
ommended, because it may cause window
fogging.
Vacation/Storage
Before you store your vehicle, or keep it out of
service (i.e., vacation) for two weeks or more,
run the air conditioning system at idle for
about five minutes, in fresh air with the
blower setting on high. This will ensure ad-
equate system lubrication to minimize the
possibility of compressor damage when the
system is started again.
Window Fogging
Vehicle windows tend to fog on the inside in
mild, rainy, and/or humid weather. To clear
the windows, select Defrost or Mix mode and
increase the front blower speed. Do not use
the Recirculation mode without A/C for long
periods, as fogging may occur.
CAUTION!
Failure to follow these cautions can cause
damage to the heating elements:
• Use care when washing the inside of
the rear window. Do not use abrasive
window cleaners on the interior surface
of the window. Use a soft cloth and a
CAUTION!
mild washing solution, wiping parallel
to the heating elements. Labels can be
peeled off after soaking with warm
water.
• Do not use scrapers, sharp instru-
ments, or abrasive window cleaners on
the interior surface of the window.
• Keep all objects a safe distance from
the window.
Outside Air Intake
Make sure the air intake, located directly in
front of the windshield, is free of obstruc-
tions, such as leaves. Leaves collected in the
air intake may reduce airflow, and if they
enter the plenum, they could plug the water
drains. In Winter months, make sure the air
intake is clear of ice, slush, and snow.
Cabin Air Filter
The climate control system filters out dust
and pollen from the air. Contact an autho-
rized dealer to service your cabin air filter,
and to have it replaced when needed.
45

WARNING!
In a collision, people riding in these
areas are more likely to be seriously
injured or killed.
• Do not allow people to ride in any area of
your vehicle that is not equipped with
seats and seat belts.
• Be sure everyone in your vehicle is in a
seat and using a seat belt properly.
Exhaust Gas
WARNING!
Exhaust gases can injure or kill. They con-
tain carbon monoxide (CO), which is col-
orless and odorless. Breathing it can make
you unconscious and can eventually poi-
son you. To avoid breathing (CO), follow
these safety tips:
• Do not run the engine in a closed garage
or in confined areas any longer than
needed to move your vehicle in or out of
the area.
WARNING!
• If you are required to drive with the
trunk/liftgate/rear doors open, make sure
that all windows are closed and the cli-
mate control BLOWER switch is set at
high speed. DO NOT use the recircula-
tion mode.
• If it is necessary to sit in a parked vehicle
with the engine running, adjust your
heating or cooling controls to force out-
side air into the vehicle. Set the blower
at high speed.
The best protection against carbon monoxide
entry into the vehicle body is a properly main-
tained engine exhaust system.
Whenever a change is noticed in the sound of
the exhaust system, when exhaust fumes can
be detected inside the vehicle, or when the
underside or rear of the vehicle is damaged,
have a competent mechanic inspect the com-
plete exhaust system and adjacent body ar-
eas for broken, damaged, deteriorated, or
mispositioned parts. Open seams or loose
connections could permit exhaust fumes to
seep into the passenger compartment. Inaddition, inspect the exhaust system each
time the vehicle is raised for lubrication or oil
change. Replace as required.
Safety Checks You Should Make Inside
The Vehicle
Seat Belts
Inspect the seat belt system periodically,
checking for cuts, frays, and loose parts.
Damaged parts must be replaced immedi-
ately. Do not disassemble or modify the sys-
tem.
Front seat belt assemblies must be replaced
after a collision. Rear seat belt assemblies
must be replaced after a collision if they have
been damaged (i.e., bent retractor, torn web-
bing, etc.). If there is any question regarding
seat belt or retractor condition, replace the
seat belt.
Air Bag Warning Light
The Air Bag warning lightwill turn on for
four to eight seconds as a bulb check when
the ignition switch is first turned to ON/RUN.
If the light is either not on during starting,
137

ESS vehicles have been upgraded with a
heavy duty starter, enhanced battery, and
other upgraded engine parts, to handle the
additional engine starts.
NOTE:
It is recommended that the Start/Stop Sys-
tem be disabled during off-road use.
Automatic Mode
The Stop/Start feature is enabled
after every normal customer en-
gine start. At that time, the sys-
tem will go into STOP/START
READY and if all other conditions are met,
can go into a STOP/START AUTOSTOP AC-
TIVE “Autostop” mode.
To Activate The Autostop Mode, The Following
Must Occur:
• The system must be in STOP/START
READY state. A STOP/START READY mes-
sage will be displayed in the instrument
cluster display within the Stop/Start sec-tion. Refer to “Instrument Cluster” in “Get-
ting To Know Your Instrument Panel” in
your Owner’s Manual for further informa-
tion.
• The vehicle must be completely stopped.
• The shifter must be in a forward gear and
the brake pedal depressed.
The engine will shut down, the tachometer
will move to the zero position and the Stop/
Start telltale will illuminate indicating you
are in Autostop. Customer settings will be
maintained upon return to an engine running
condition.
Refer to the “Stop/Start System” in the
“Starting And Operating” section located in
your Owner’s Manual for further information.
Possible Reasons The Engine Does Not
Autostop
Prior to engine shut down, the system will
check many safety and comfort conditions to
see if they are fulfilled. Detailed information
about the operation of the Stop/Start system
may be viewed in the instrument clusterdisplay Stop/Start Screen. In the following
situations, the engine will not stop:
• Driver’s seat belt is not buckled.
• Driver’s door is not closed.
• Battery temperature is too warm or cold.
• Battery charge is low.
• The vehicle is on a steep grade.
• Cabin heating or cooling is in process and
an acceptable cabin temperature has not
been achieved.
• HVAC is set to full defrost mode at a high
blower speed.
• HVAC set to MAX A/C.
• Engine has not reached normal operating
temperature.
• Engine temperature too high.
• The transmission is not in a forward gear.
• Hood is open.
• Transfer case is in 4LO or Neutral.
• Brake pedal is not pressed with sufficient
pressure.
STARTING AND OPERATING
158

Cavity Cartridge Fuse Micro Fuse Description
F05 – 5 Amp Tan Security Gateway
(*)
F06 – – Spare
F07 – 15 Amp Blue Low Temp Radiator Cooling Pump (LTR) — If Equipped
(*)
F08 – 15 Amp Blue Trans Control Module TCM-8HP CYGNUS
(*)
F09 – – Spare
F10 – 15 Amp Blue Key Ignition Node (KIN)/Radio Frequency Hub(RF HUB)/
Electric Steering Column Lock (ESCL)
(*)
F11 – 10 Amp Red UCI Port (USB & AUX)
F12 – 25 Amp Clear HIFI Amplifier
F13 – – Spare
F14 – – Spare
F15 – 15 Amp Blue Instrument Panel Cluster (IPC)/Switch Bank-Heavy Duty
Electrical Pkg (SWITCH BANK-HD ELEC)
(*)
F16 – – Spare
F17 – – Spare
F18 – 10 Amp Red Air Conditioning Clutch (AC CLUTCH)
(*)
F19 – – Spare
F20 30 Amp Pink – Central Body Controller (CBC) 1-INTERIOR LIGHTS
F21 – 20 Amp Yellow REAR WIPER
IN CASE OF EMERGENCY
182

CAUTION!
Do not use a portable battery booster pack
or any other booster source with a system
voltage greater than 12 Volts or damage to
the battery, starter motor, alternator or
electrical system may occur.
NOTE:
When using a portable battery booster pack,
follow the manufacturer's operating instruc-
tions and precautions.
Preparations For Jump Start
The battery in your vehicle is located in the
left rear of the engine compartment, behind
the Power Distribution Center.NOTE:
The positive battery post is covered with a
protective cap. Lift up on the cap to gain
access to the post.
WARNING!
• Take care to avoid the radiator cooling
fan whenever the hood is raised. It can
start anytime the ignition switch is ON.
You can be injured by moving fan blades.
WARNING!
• Remove any metal jewelry such as rings,
watch bands and bracelets that could
make an inadvertent electrical contact.
You could be seriously injured.
• Batteries contain sulfuric acid that can
burn your skin or eyes and generate
hydrogen gas which is flammable and
explosive. Keep open flames or sparks
away from the battery.
NOTE:
Never use a fast battery charger to start the
engine, as this could damage the electronic
systems of your vehicle, particularly the igni-
tion and engine fuel supply control units.
1. Apply the parking brake, shift the auto-
matic transmission into PARK and turn
the ignition OFF.
2. Turn off the heater, radio, and all unnec-
essary electrical accessories.
3. If using another vehicle to jump start the
battery, park the vehicle within the jumper
cable’s reach, apply the parking brake and
make sure the ignition is OFF.
Positive Battery Post
197

4. Disconnect the opposite end of the posi-
tive(+)jumper cable from the remote
positive(+)post of the discharged
vehicle.
5. Reinstall the protective cover over the
remote positive(+)post of the discharged
vehicle.
If frequent jump starting is required to start
your vehicle you should have the battery and
charging system tested at an authorized
dealer.
CAUTION!
Accessories plugged into the vehicle
power outlets draw power from the vehi-
cle’s battery, even when not in use (i.e.,
cellular devices, etc.). Eventually, if
plugged in long enough without engine
operation, the vehicle’s battery will dis-
charge sufficiently to degrade battery life
and/or prevent the engine from starting.
IF YOUR ENGINE
OVERHEATS
In any of the following situations, you can
reduce the potential for overheating by taking
the appropriate action.
• On the highways — slow down.
• In city traffic — while stopped, shift trans-
mission into NEUTRAL, but do not increase
engine idle speed.
CAUTION!
Driving with a hot cooling system could
damage your vehicle. If the temperature
gauge reads HOT (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 HOT (H), and you hear
continuous chimes, turn the engine off
immediately and call for service.NOTE:
There are steps that you can take to slow
down an impending overheat condition:
• If your air conditioner (A/C) is on, turn it off.
The A/C system adds heat to the engine
cooling system and turning the A/C off can
help remove this heat.
• You can also turn the temperature control to
maximum heat, the mode control to floor
and the blower control to high. This allows
the heater core to act as a supplement to
the radiator and aids in removing heat from
the engine cooling system.WARNING!
You or others can be badly burned by hot
engine coolant (antifreeze) or steam from
your radiator. If you see or hear steam
coming from under the hood, do not open
the hood until the radiator has had time to
cool. Never try to open a cooling system
pressure cap when the radiator or coolant
bottle is hot.
199

SERVICING AND MAINTENANCE
SCHEDULED SERVICING......208
Scheduled Servicing — Gasoline Engine.208
Scheduled Servicing — Diesel Engine .213
ENGINE COMPARTMENT......217
2.0L Gasoline Engine............217
3.6L Gasoline Engine............218
2.2L Diesel Engine.............219
Checking Oil Level — Gasoline Engine .220
Adding Washer Fluid............220
Maintenance-Free Battery........221
DEALER SERVICE...........221
Windshield Wiper Blades.........222
Cooling System...............224
Brake System................224
Automatic Transmission..........225
RAISING THE VEHICLE.......226
TIRES....................226
Tire Safety Information..........226
Tires — General Information.......230
Tire Types...................234
Spare Tires — If Equipped........235
Wheel And Wheel Trim Care.......236Tire Chains (Traction Devices).......237
Tire Rotation Recommendations.....238
STORING THE VEHICLE......239
BODYWORK...............239
Body And Underbody Maintenance . . .239
Preserving The Bodywork.........239
INTERIORS................242
Seats And Fabric Parts...........242
Plastic And Coated Parts..........243
Leather Parts.................243
Glass Surfaces...............243
SERVICING AND MAINTENANCE
207