2018 JEEP WRANGLER UNLIMITED engine coolant

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

— Battery Charge Warning Light
This warning light will illuminate when the
battery is not charging properly. If it stays on
while the engine is running, there may be a
malfunction with the charging system. Con-
tact an authorized dealer as soon as possible.
This indicates a possible problem with the
electrical system or a related component.
— Door Open Warning Light
This indicator will illuminate when a door is
ajar/open and not fully closed.
NOTE:
If the vehicle is moving, there will also be a
single chime.
— Electric Power Steering Fault
Warning Light
This warning light will turn on when there's a
fault with the EPS (Electric Power Steering)
system. Refer to “Power Steering” in “Start-
ing And Operating” in the Owner’s Manual for
further information.
WARNING!
Continued operation with reduced assist
could pose a safety risk to yourself and
others. Service should be obtained as soon
as possible.
— Electronic Throttle Control (ETC)
Warning Light
This warning light will illuminate to indicate
a problem with the Electronic Throttle Con-
trol (ETC) system. If a problem is detected
while the vehicle is running, the light will
either stay on or flash depending on the
nature of the problem. Cycle the ignition
when the vehicle is safely and completely
stopped and the transmission is placed in the
PARK position. The light should turn off. If
the light remains on with the vehicle running,
your vehicle will usually be drivable; however,
see an authorized dealer for service as soon
as possible.
NOTE:
This light may turn on if the accelerator and
brake pedals are pressed at the same time.If the light continues to flash when the ve-
hicle is running, immediate service is re-
quired and you may experience reduced per-
formance, an elevated/rough idle, or engine
stall and your vehicle may require towing.
The light will come on when the ignition is
placed in the ON/RUN or ACC/ON/RUN posi-
tion and remain on briefly as a bulb check. If
the light does not come on during starting,
have the system checked by an authorized
dealer.
— Engine Coolant Temperature Warn-
ing Light
This warning light warns of an overheated
engine condition. If the engine coolant tem-
perature is too high, this indicator will illumi-
nate and a single chime will sound. If the
temperature reaches the upper limit, a con-
tinuous 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
GETTING TO KNOW YOUR INSTRUMENT PANEL
68

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 assures
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 theengine three to five minutes before shutting it
down. This idle period will allow the lubricat-
ing oil and coolant to carry excess heat away
from the combustion chamber, bearings, in-
ternal components, and turbocharger. This is
especially important for turbocharged,
charge air cooled engines.
TURBOCHARGER "COOL DOWN" CHART
Driving
ConditionsLoad Turbocharger
TemperatureIdle Time (In Minutes)
Before Shut Down
Stop & Go Empty Cool Less than 1
Stop & Go Medium Warm 1
Highway Speeds Medium Warm 2
City Traffic Max. GCWR Warm 3
Highway Speeds Max. GCWR Warm 4
Uphill Grade Max. GCWR Hot 5
ENGINE BREAK-IN
RECOMMENDATIONS
A long break-in period is not required for the
engine and drivetrain (transmission and axle)
in your vehicle.Drive moderately during the first 300 miles
(500 km). After the initial 60 miles
(100 km), speeds up to 50 or 55 mph (80 or
90 km/h) are desirable.While cruising, brief full-throttle acceleration
within the limits of local traffic laws contrib-
utes to a good break-in. Wide-open throttle
acceleration in low gear can be detrimental
and should be avoided.
STARTING AND OPERATING
146

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

Your authorized dealer will reset the oil
change indicator message after completing
the scheduled oil change.
Once A Month Or Before A Long Trip
• Check the engine oil level about five min-
utes 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, even if it occurs
before the oil indicator system turns on.• 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.
CAUTION!
Failure to perform the required mainte-
nance items may result in damage to the
vehicle.Required Maintenance Intervals
Refer to the Maintenance Plan on the follow-
ing pages for the required maintenance inter-
vals.
Maintenance Plan
NOTE:
Once you have carried out the last interven-
tion in the table, continue with the scheduled
servicing, maintaining the frequency indi-
cated in the plan by marking each operation
with a dot or dedicated note. Simply restart-
ing the maintenance from the start of the
plan may cause the allowed interval to be
exceeded for some operations.
209

Mileage or time passed (which-
ever 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
Replace air conditioning/cabin
air filter.XX X X X X
Replace spark plugs (2.0L En-
gine) ****XX X X X X
Replace spark plugs (3.6L En-
gine) ****XX
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.XX
Change transfer case fluid if us-
ing your vehicle for any of the
following: police, taxi, fleet, or
frequent trailer towing.XX
Inspect and replace PCV valve if
necessary. *****X
* The actual interval for changing the oil and
replacing the engine oil filter depends on the
vehicle usage condition, it is signaled bythew warning light or message (if equipped)
in the instrument cluster display. It should
not exceed 10,000 miles (16,000 km) or
12 months.** See “Severe Duty Conditions” in this sec-
tion.
*** DOT 4 brake fluid is time based only;
mileage intervals do not apply.
SERVICING AND MAINTENANCE
212

**** The spark plug change interval is mile-
age 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.
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 com-
petent 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.
Severe Duty Conditions
Change the engine oil and engine oil filter at
every 4500 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 (commercial
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 dis-
played and a single chime will sound, indi-
cating that an oil change is necessary.
On non-instrument cluster display equipped
vehicles, “Change Oil” will flash in the instru-
ment 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 fre-
quent 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 instru-
ment cluster. In any case, it must never ex-
ceed two years. If the vehicle is used mainly
for city driving, change the engine oil and
filter every year.
•Flush and replace the engine coolant at
120 months or 150,000 miles (240,000 km)
whichever comes first.
213

•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.
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 reser-
voir and brake master cylinder, fill as
needed.
• Check function of all interior and exterior
lights.
• Control and recovery of additive level for
AdBlue Diesel emissions (UREA) (if
equipped).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.
CAUTION!
Failure to perform the required mainte-
nance items may result in damage to the
vehicle.
Maintenance Plan — Diesel Engine
Required Maintenance Intervals
Refer to the maintenance plan on the follow-
ing pages for the required maintenance inter-
vals.
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
At Every Oil Change Interval As Indicated By Oil
Change Indicator System:
• Inspect battery and clean and tighten ter-
minals as required
• 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.
NOTE:
Once you have carried out the last interven-
tion in the table, continue with the scheduled
servicing, maintaining the frequency indi-
cated in the plan by marking each operation
with a dot or dedicated note. Simply restart-
ing the maintenance from the start of the
plan may cause the allowed interval to be
exceeded for some operations.SERVICING AND MAINTENANCE
214