engine coolant JEEP WRANGLER UNLIMITED 2020 Owner handbook (in English)

45
The temperature can be displayed in U.S.
or Metric units by selecting the U.S./
Metric customer-programmable feature.
Refer to the “Uconnect Settings” in
“Multimedia” in the 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.
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 provide proper corrosion protec -
tion and to protect against engine over -
heating. OAT coolant (conforming to
MS.90032) is recommended.
Winter Operation
To ensure the best possible heater and
defroster 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
recommended, 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
adequate 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.
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.
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 mild
washing solution, wiping parallel to the
heating elements. Labels can be peeled
off after soaking with warm water.
Do not use scrapers, sharp instruments,
or abrasive window cleaners on the inte-
rior surface of the window.
Keep all objects a safe distance from the
window.
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67
— Engine Coolant Temperature Warning
Light
This warning light warns of an overheated
engine condition. If the engine coolant
temperature is too high, this indicator will
illuminate and a single chime will sound. If
the temperature reaches the upper limit, a
continuous chime will sound for four
minutes or until the engine is able to cool;
whichever comes first.
If the light turns on while driving, safely pull
over and stop the vehicle. If the A/C system
is on, turn it off. Also, shift the transmission
into Park and allow the vehicle to sit idle
(propulsion system active). If the tempera -
ture reading does not return to normal, turn
the engine off immediately and call for
service.
Refer to “If Your Engine Overheats” in “In
Case Of Emergency” for further information.
— Hood Open Warning Light
This indicator will illuminate when the hood
is ajar/open or not fully closed.
NOTE:
If the vehicle is moving, there will also be a
single chime.
— Oil Pressure Warning Light
This warning light will illuminate to indicate
low engine oil pressure. If the light turns on
while driving, stop the vehicle, shut off the
engine as soon as possible, and contact an
authorized dealer. A chime will sound when
this light turns on.
Do not operate the vehicle until the cause is
corrected. This light does not indicate how
much oil is in the engine. The engine oil level
must be checked under the hood.
— Oil Temperature Warning Light
This warning light will illuminate to indicate
the engine oil temperature is high. If the
light turns on while driving, stop the vehicle
and shut off the engine as soon as possible.
Wait for oil temperature to return to normal
levels.
— Seat Belt Reminder Warning Light
This warning light indicates when the driver
or passenger seat belt is unbuckled. When
the ignition is first placed in the ON/RUN or
ACC/ON/RUN position and if the driver’s
seat belt is unbuckled, a chime will sound
and the light will turn on. When driving, if the driver or front passenger seat belt
remains unbuckled, the Seat Belt Reminder
Light will flash or remain on continuously
and a chime will sound.
Refer to “Occupant Restraint Systems” in
“Safety” for further information.
— Rear Seat Belt Reminder Warning Light
— If Equipped
This light indicates when a rear seat belt is
unbuckled in the second row. When the igni -
tion is first placed in the ON/RUN or ACC/
ON/RUN position, and if a seat belt in the
second row is unbuckled, a light corre -
sponding to the specific seat will turn on in
the upper right portion of the instrument
cluster display, momentarily replacing the
configurable corner information. If a second
row seat belt that was buckled at the start of
the trip is unbuckled, the Rear Seat Belt
Reminder Light will change from green to red
and a single chime will sound.
Refer to “Occupant Restraint Systems” in
“Safety” for further information.
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137
(Continued)
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 side-
walls 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 indi -
cator lights on the instrument panel.

Door Latches
Check for proper closing, latching, and
locking.
Fluid Leaks
Check area under 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.
ALWAYS REMOVE THE EXISTING
FLOOR MAT FROM THE VEHICLE
before installing any other floor mat.
NEVER install or stack an additional
floor mat on top of an existing floor mat.
ONLY install floor mats designed to fit
your vehicle. NEVER install a floor mat
that cannot be properly attached and
secured to your vehicle. If a floor mat
needs to be replaced, only use a FCA
approved floor mat for the specific make,
model, and year of your vehicle.
ONLY use the driver’s side floor mat on
the driver’s side floor area. To check for
interference, with the vehicle properly
parked with the engine off, fully depress
the accelerator, the brake, and the
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.
WARNING! (Continued)
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
objects 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
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 acceler -
ator, 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
secured to your vehicle using the floor
mat fasteners by lightly pulling mat.
WARNING! (Continued)
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STARTING AND OPERATING
142
Diesel Engine Idling — In Cold Weather
Avoid prolonged idling in ambient tempera-
tures below 0°F (-18°C). Long periods of
idling may be harmful to your engine
because combustion chamber temperatures
can drop so low that the fuel may not burn
completely. Incomplete combustion allows
carbon and varnish to form on piston rings
and injector nozzles. Also, the unburned fuel
can enter the crankcase, diluting the oil and
causing rapid wear to the engine.
Stopping the Engine
The following chart should be used as a
guide in determining the amount of engine
idle time required to sufficiently cool down
the turbocharger before shut down,
depending upon the type of driving and the
amount of cargo.
Before turning off your turbo diesel engine,
always allow the engine to return to normal idle
speed and run for several seconds. This
ensures proper lubrication of the turbocharger. This is particularly necessary after any period
of hard driving.
Idle the engine a few minutes before routine
shutdown. After full load operation, idle the
engine three to five minutes before shutting
it down. This idle period will allow the lubri
-
cating oil and coolant to carry excess heat
away from the combustion chamber, bear -
ings, internal components, and turbo -
charger. This is especially important for
turbocharged, charge air cooled engines.
Turbocharger "Cool Down" Chart
Driving
Conditions Load
Turbocharger
Temperature Idle Time (In Minutes)
Before Shut Down
Stop & Go EmptyCoolLess than 1
Stop & Go Medium Warm1
Highway Speeds MediumWarm2
City Traffic Max. GCWR Warm3
Highway Speeds Max. GCWR Warm4
Uphill Grade Max. GCWR Hot5
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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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211
Once A Month Or Before A Long Trip
Check the engine oil level about five
minutes after a fully warmed engine is
shut off. Checking the oil level while the
vehicle is on level ground will improve the
accuracy of the oil level reading. Add oil
only when the level is at or below the ADD
or MIN mark.
Check the windshield washer solvent and
add if required.
Check tire pressure and look for unusual
wear or damage. Rotate tires at the first
sign of irregular wear.
Inspect the battery and clean and tighten
the terminals as required.
Check the fluid levels of coolant reservoir,
brake master cylinder and power steering
and fill as needed.
Check all lights and other electrical items
for correct operation.At Each Oil Change
Change the engine oil filter.
Inspect the brake hoses and lines.
Inspect the CV/Universal joints.
Check tire pressure and look for unusual
wear or damage. Rotate tires at the first
sign of irregular wear, even if it occurs
before the oil indicator system turns on.
Required Maintenance Intervals
Refer to the Maintenance Plan on the
following pages for the required maintenance
intervals.
Maintenance Plan
NOTE:
Once you have carried out the last interven -
tion in the table, continue with the sched -
uled servicing, maintaining the frequency
indicated in the plan by marking each oper -
ation with a dot or dedicated note. Simply
restarting the maintenance from the start of
the plan may cause the allowed interval to be
exceeded for some operations.
CAUTION!
Failure to perform the required
maintenance items may result in damage
to the vehicle.
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215
* See “Severe Duty Conditions” in this
section.
** DOT 4 brake fluid is time based only;
mileage intervals do not apply.*** The spark plug change interval is
mileage based only, yearly intervals do not
apply.
**** This maintenance is recommended by
the manufacturer to the owner, but is not
required to maintain emissions warranty.
Replace accessory drive
belt(s).
X

Flush and replace the
engine coolant at 10
years or 150,000 miles
(240,000 km) whichever
comes first.
X
X

Change transfer case fluid
if using your vehicle for
any of the following:
police, taxi, fleet, or
frequent trailer towing.
X
X
Inspect and replace PCV
valve if necessary. **** X
Mileage or time passed
(whichever comes first)
7,500
15,000
22,500
30,000
37,500
45,000
52,500
60,000
67,500
75,000
82,500
90,000
97,500
105,000
112,500
120,000
127,500
135,000
142,500
150,000
Or Months: 12 24 36 48 60 72 84 96 108 120 132 144 156 168 180 192 204 216 228 240
Or Kilometers:
12,000
24,000
36,000
48,000
60,000
72,000
84,000
96,000
108,000
120,000
132,000
144,000
156,000
168,000
180,000
192,000
204,000
216,000
228,000
240,000
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SERVICING AND MAINTENANCE
216
Severe Duty Conditions
Change the engine oil and engine oil filter at
every 4,500 miles (7,500 km) or 6 months
if using your vehicle under any of the
following severe duty conditions:
Stop and go driving.
Driving in dusty conditions.
Short trips of less than 10 miles (16 km).
Trailer towing.
Taxi, police, or delivery service (commer-
cial service).
Off-road or desert operation.
Scheduled Servicing — Diesel Engine
Your vehicle is equipped with an automatic
oil change indicator system. The oil change
indicator system will remind you that it is
time to take your vehicle in for engine oil
replacement.
On vehicles equipped with instrument
cluster display, “Oil Change Required” will
be displayed and a single chime will sound,
indicating that an oil change is necessary.
On non-instrument cluster display equipped
vehicles, “Change Oil” will flash in the
instrument cluster odometer and a single
chime will sound, indicating that an oil
change is necessary.

Based on engine operation conditions, the oil
change indicator message will illuminate. This
means that service is required for your vehicle.
Operating conditions such as frequent
short-trips, trailer tow, extremely hot or cold
ambient temperatures will influence when the
“Oil Change Required” message is displayed. Severe Operating Conditions can cause the
change oil message to illuminate as earlier than
specified. Have your vehicle serviced as soon
as possible, within the next 500 miles
(805 km).

NOTE:
The actual interval for changing engine oil
and replacing the engine oil filter depends
on the vehicle usage conditions, and is
signaled by the warning light or message
in the instrument panel. In any case, it
must never exceed 12,500 miles
(20,000 km) or 1 year
Flush and replace the engine coolant at
120 months or 150,000 miles (240,000 km)
whichever comes first.
The maximum mileage is 75,000 mi
(120,000 km). The belt must be replaced
every 5 years regardless of distance trav-
eled. The timing and accessory belts must be
changed every 37,500 miles (60,000 km) or
3 years for particularly demanding use
(dusty areas, severe weather conditions,
very low or very high temperatures for
extended periods, city driving, long periods
of idling). Under no circumstances should
these intervals be exceeded.
WARNING!
You can be badly injured working on or
around a motor vehicle. Do only service
work for which you have the knowledge
and the right equipment. If you have any
doubt about your ability to perform a
service job, take your vehicle to a compe-
tent mechanic.
Failure to properly inspect and maintain
your vehicle could result in a component
malfunction and effect vehicle handling
and performance. This could cause an
accident.
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217
Once A Month Or Before A Long Trip
Check engine oil level.
Check windshield washer fluid level.
Check tire pressure and look for unusual
wear or damage. Rotate tires at the first
sign of irregular wear, even if it occurs
before the oil indicator system turns on.

Check the fluid levels of the coolant reservoir
and brake master cylinder, fill as needed.

Check function of all interior and exterior lights.Demanding Vehicle Use
Restore additive level for AdBlue® Diesel
emissions (UREA) (if equipped), when the
lamp is illuminated or the message on the
instrument panel.
Maintenance Plan — Diesel Engine
Required Maintenance Intervals
Refer to the maintenance plan on the
following pages for the required maintenance
intervals.
NOTE:
Once you have carried out the last intervention in the table, continue with the scheduled servicing, maintaining the frequency indicated in
the plan by marking each operation with a dot or dedicated note. Simply restarting the maintenance from the start of the plan may cause the
allowed interval to be exceeded for some operations.
CAUTION!

Failure to perform the required maintenance
items may result in damage to the vehicle.

At Every Oil Change Interval As Indicated By Oil Change Indicator System:
Change oil and filter
Rotate the tires. Rotate at the first sign of irregular wear, even if it occurs before the oil indicator system turns on
Inspect battery and clean and tighten terminals as required
Inspect the CV/Universal joints
Inspect brake pads, shoes, rotors, drums, hoses and park brake
Inspect engine cooling system protection and hoses
Inspect exhaust system
Inspect engine air cleaner if using in dusty or off-road conditions
Inspect all door latches for presence of grease, reapply if necessary.
Inspect coolant level.
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219
Additional Maintenance
Replace engine air cleaner filter.X X X X X X X
Replace air conditioning/cabin air filter. X X X X X X X
Change brake fluid every 24 months if using DOT 4
brake fluid. (**) X X X X X X X
Replace the engine fuel filter. X X X X X X X
Inspect accessory drive and timing belt. XX X
Replace accessory drive belt. (***) XX
Flush and replace the engine coolant at 10 years or
150,000 miles (240,000 km) whichever comes first. X X
Replace timing drive belt. (***) XX
Mileage or time passed (whichever comes first)
12,500
25,000
37,500
50,000
62,500
75,000
87,500
100,000
112,500
125,000
137,500
150,000
162,500
175,000
187,500
Or Years: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Or Kilometers:
20,000
40,000
60,000
80,000
100,000
120,000
140,000
160,000
180,000
200,000
220,000
240,000
260,000
280,000
300,000
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