2020 JEEP WRANGLER UNLIMITED radiator

GETTING TO KNOW YOUR VEHICLE
44
Climate Control Functions
A/C (Air Conditioning)
The Air Conditioning (A/C) button allows the
operator to manually activate or deactivate
the air conditioning system. When the air
conditioning system is turned on, cool dehu-
midified air will flow through the outlets into
the cabin. For improved fuel economy, press
the A/C button to turn off the air conditioning
and manually adjust the blower and airflow
mode settings. Also, make sure to select only
Panel, Bi-Level, or Floor modes.
NOTE:
For Manual Climate Controls, if the system
is in Mix, Floor or Defrost Mode, the A/C
can be turned off, but the A/C system shall
remain active to prevent fogging of the
windows.
If fog or mist appears on the windshield or
side glass, select Defrost mode, and
increase blower speed if needed.
If your air conditioning performance
seems lower than expected, check the
front of the A/C condenser (located in front
of the radiator), for an accumulation of dirt or insects. Clean with a gentle water spray
from the front of the radiator and through
the condenser.
MAX A/C
MAX A/C sets the control for maximum
cooling performance.

Press and release to toggle between MAX A/C
and the prior settings. The button illuminates
when MAX A/C is on.

In MAX A/C, the blower level and mode position
can be adjusted to desired user settings.
Pressing other settings will cause the MAX A/C
operation to switch to the selected setting and
MAX A/C to exit.

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 that you would like the system to maintain by
adjusting the driver and passenger
temperature control buttons. Once the
desired temperature 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 tempera-
ture settings for cold or hot vehicles. The
system automatically adjusts the tempera-
ture, mode, and blower speed to provide
comfort as quickly as possible.
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IN CASE OF EMERGENCY
184
Power Distribution Center (PDC)
The Power Distribution Center (PDC) is
located in the engine compartment near the
battery. This center contains cartridge fuses,
mini fuses, and relays. The PDC top cover is
labeled with each serviceable fuse/relay loca-
tion, function, and size. NOTE:
Fuses for safety systems (marked with *)
must be serviced by an authorized dealer.
Power Distribution Center
CavityCartridge Fuse Micro Fuse Description
F01– –Spare
F02 40 Amp Green –Starter
(*)
F03 –5 Amp Tan Intelligent Battery Sensor (IBS)
(*)
F04 –20 Amp Yellow Fuel Pump MTR/FPCM
(*)
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
(*)
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201
JUMP STARTING
If your vehicle has a discharged battery, it
can be jump started using a set of jumper
cables and a battery in another vehicle, or by
using a portable battery booster pack. Jump
starting can be dangerous if done improp-
erly, so please follow the procedures in this
section carefully.
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.
Positive Battery Post
Positive Battery Post NOTE:
The positive battery post is covered with a
protective cap. Lift up on the cap to gain
access to the post.
WARNING!
Do not attempt jump starting if the battery
is frozen. It could rupture or explode and
cause personal injury.
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.
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.
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.
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IN CASE OF EMERGENCY
204
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 (N), but do not
increase engine idle speed.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 supple-
ment to the radiator and aids in removing
heat from the engine cooling system.
MANUAL PARK RELEASE
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.
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.
WARNING!
Always secure your vehicle by fully
applying the parking brake before
activating the Manual Park Release. In
addition, you should be seated in the
driver’s seat with your foot firmly on the
brake pedal when activating the Manual
Park Release. Activating the Manual Park
Release will allow your vehicle to roll away
if it is not secured by the parking brake, or
by proper connection to a tow vehicle.
Activating the Manual Park Release on an
unsecured vehicle could lead to serious
injury or death for those in or around the
vehicle.
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SERVICING AND MAINTENANCE
224
(Continued)
Checking Oil Level — Gasoline Engine
To ensure proper lubrication of your vehicle's
engine, the engine oil must be maintained at
the correct level. The engine oil level should
be checked five minutes after a warmed up
engine has been shut off.
Checking the oil while the vehicle is on level
ground will improve the accuracy of the oil
level readings. Always maintain the oil level
within the SAFE zone on the dipstick. Adding
1 quart (0.95 liters) of oil when the reading
is at the bottom of the crosshatch zone will
result in a reading at the top of the cross-
hatch zone on these engines.
Adding Washer Fluid
The fluid reservoir for the windshield
washers and the rear window washer (if
equipped) is shared. The fluid reservoir is
located in the engine compartment. Be sure
to check the fluid level at regular intervals.
Fill the reservoir with windshield washer
solvent only (not radiator antifreeze). When
refilling the washer fluid reservoir, take some
washer fluid and apply it to a cloth or towel
and wipe clean the wiper blades; this will
help blade performance.
To prevent freeze-up of your windshield
washer system in cold weather, select a solu -
tion or mixture that meets or exceeds the
temperature range of your climate. This
rating information can be found on most
washer fluid containers. WARNING!

Never smoke while working in the engine
compartment: gas and inflammable vapors
may be present, with the risk of fire.

Be very careful when working in the
engine compartment when the engine is
hot: you may get burned. Do not get too
close to the radiator cooling fan: the
electric fan may start; danger of injury.
Scarves, ties and other loose clothing
might be pulled by moving parts.
CAUTION!
Be careful not to confuse the various
types of fluids while topping up: they are
not compatible with each other! Topping
up with an unsuitable fluid could
severely damage your car.
The oil level must never exceed the MAX
mark.
Always top up using engine oil of the
same specifications as that already in
the engine.
If the engine oil is being topped up, wait
for the engine to cool down before loos-
ening the filler cap, particularly for vehi -
cles with aluminium cap (if equipped).
WARNING: risk of burns!
Overfilling or underfilling the crankcase
will cause aeration or loss of oil pressure.
This could damage your engine.
CAUTION! (Continued)
WARNING!
Commercial windshield washer solvents
are flammable. They could ignite and burn
you. Care must be exercised when filling or
working around the washer solution.
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229
(Continued)
Under normal operating conditions, the cata-
lytic converter will not require maintenance.
However, it is important to keep the engine
properly tuned to ensure proper catalyst
operation and prevent possible catalyst
damage.
NOTE:
Intentional tampering with emissions control
systems can result in civil penalties being
assessed against you.
In unusual situations involving grossly
malfunctioning engine operation, a
scorching odor may suggest severe and
abnormal catalyst overheating. If this occurs,
stop the vehicle, turn off the engine and
allow it to cool. Service, including a tune-up
to manufacturer's specifications, should be
obtained immediately.
To minimize the possibility of catalytic
converter damage:
Do not interrupt the ignition when the
transmission is in gear and the vehicle is
in motion.
Do not try to start the vehicle by pushing
or towing the vehicle.
Do not idle the engine with any ignition
components disconnected or removed,
such as when diagnostic testing, or for
prolonged periods during very rough idle or
malfunctioning operating conditions.
Cooling System

A hot exhaust system can start a fire if you
park over materials that can burn. Such
materials might be grass or leaves coming
into contact with your exhaust system. Do not
park or operate your vehicle in areas where
your exhaust system can contact anything
that can burn.

CAUTION!

The catalytic converter requires the use of
unleaded fuel only. Leaded gasoline will
destroy the effectiveness of the catalyst as an
emissions control device and may seriously
reduce engine performance and cause
serious damage to the engine.
Damage to the catalytic converter can result
if your vehicle is not kept in proper operating
condition. In the event of engine malfunc -
tion, particularly involving engine misfire or
other apparent loss of performance, have your
vehicle serviced promptly. Continued opera-
tion of your vehicle with a severe malfunction
could cause the converter to overheat,
resulting in possible damage to the converter
and vehicle.

WARNING! (Continued)
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 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.
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SERVICING AND MAINTENANCE
230(Continued)
Coolant Checks
Check the engine and, intercooler (if
equipped) coolant (antifreeze) protection
every 12 months (before the onset of
freezing weather, where applicable). If the
engine and, intercooler (if equipped) is dirty
or rusty in appearance, the system 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 (if equipped) or radiator for any
accumulation of bugs, leaves, etc. If dirty,
clean by gently spraying water from a garden
hose vertically down the face of the A/C
condenser (if equipped) or the back of the
radiator core.Check the engine and, intercooler (if
equipped) cooling system hoses for brittle
rubber, cracking, tears, cuts, and tightness
of the connection at the coolant recovery
bottle and radiator. Inspect the entire system
for leaks. DO NOT REMOVE THE COOLANT
PRESSURE CAP WHEN THE COOLING
SYSTEM IS HOT.
Brake System
In order to ensure brake system perfor
-
mance, all brake system components should
be inspected periodically. Refer to the
“Maintenance Plan” in this section for the
proper maintenance intervals.
Fluid Level Check — Brake Master Cylinder
The fluid level of the master cylinder should
be checked whenever the vehicle is serviced,
or immediately if the brake system warning
light is on. If necessary, add fluid to bring
level within the designated marks on the side
of the reservoir of the brake master cylinder.
Be sure to clean the top of the master
cylinder area before removing cap. With disc
brakes, fluid level can be expected to fall as
the brake pads wear. Brake fluid level should
be checked when pads are replaced. If the
brake fluid is abnormally low, check the
system for leaks.
Refer to “Fluids And Lubricants” in “Tech -
nical Specifications” for further information.When working near the radiator cooling
fan, 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.
WARNING! (Continued)
WARNING!
Riding the brakes can lead to brake failure
and possibly a collision. Driving with your
foot resting or riding on the brake pedal
can result in abnormally high brake
temperatures, excessive lining wear, and
possible brake damage. You would not
have your full braking capacity in an
emergency. WARNING!
Use only manufacturer's recommended
brake fluid. Refer to “Fluids And Lubri -
cants” in “Technical Specifications” for
further information. Using the wrong
type of brake fluid can severely damage
your brake system and/or impair its
performance. The proper type of brake
fluid for your vehicle is also identified on
the original factory installed hydraulic
master cylinder reservoir.
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241
Tire Rotation Recommendations
The tires on the front and rear of your vehicle
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 rota-
tion 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 Plan” for the
proper maintenance intervals. The reasons
for any rapid or unusual wear should be
corrected prior to rotation being performed.
The suggested rotation method is the “rear
-
ward-cross” shown in the following diagram.
Tire Rotation (Rearward Cross)
STORING THE VEHICLE

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.
CAUTION! (Continued)
CAUTION!
Proper operation of four-wheel drive
vehicles depends on tires of equal size,
type and circumference on each wheel.
Any difference in tire size can cause
damage to the transfer case. Tire rotation
schedule should be followed to balance
tire wear.
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.
Remove any metal jewelry such as rings,
watch bands and bracelets that could
make an inadvertent electrical contact.
You could be seriously injured.
Vehicles with the Stop/Start system will
be equipped with two batteries. Both the
main and the supplemental batteries
must be disconnected to completely
de-energize the 12 Volt electrical
system.
Serious injury or death could result if you
do not disconnect both batteries. To
learn how to properly disconnect, see
your authorized dealer.
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