2023 JEEP WRANGLER cooling

182STARTING AND OPERATING
DRIVING ACROSS AN INCLINE
If at all possible, avoid driving across an incline. If it is
necessary, know your vehicle's abilities. Driving across an
incline places more weight on the downhill wheels, which
increases the possibilities of a downhill slide or rollover.
Make sure the surface has good traction with firm and
stable soils. If possible, transverse the incline at an angle
heading slightly up or down.
IF YOU STALL OR BEGIN TO LOSE HEADWAY
If you stall or begin to lose headway while climbing a steep
hill, allow your vehicle to come to a stop and immediately
apply the brake. Restart the engine and shift into
REVERSE. Back slowly down the hill allowing engine
braking to control the descent and apply your brakes, if
necessary, but do not allow the tires to lock.
Driving Through Water
Extreme care should be taken crossing any type of water.
Water crossings should be avoided, if possible, and only
be attempted when necessary in a safe, responsible
manner. Only drive through areas which are designated
and approved. Tread lightly and avoid damage to the
environment. Know your vehicle's abilities and be able to
recover it if something goes wrong. Never stop or shut a
vehicle off when crossing deep water unless you ingested
water into the engine air intake. If the engine stalls, do not
attempt to restart it. Determine if it has ingested water
first. The key to any crossing is low and slow. Shift into
FIRST gear (manual transmission), or DRIVE (automatic
transmission), with the transfer case in the 4L position
and proceed very slowly with a constant slow speed of {3
to 5 mph (5 to 8 km/h) maximum} and light throttle. Keep
the vehicle moving; do not try to accelerate through the
crossing. After crossing any water higher than the bottom
of the axle differentials, inspect all of the vehicle fluids for
signs of water ingestion.
BEFORE YOU CROSS ANY TYPE OF WATER
As you approach any type of water, you need to determine
if you can cross it safely and responsibly. If necessary, get
out and walk through the water or probe it with a stick. You
need to be sure of its depth, approach angle, current and
bottom condition. Be careful of murky or muddy waters;
check for hidden obstacles. Make sure you will not be
intruding on any wildlife, and you can recover the vehicle
if necessary. The key to a safe crossing is the water depth,
current and bottom conditions. On soft bottoms, the
vehicle will sink in, effectively increasing the water level on
the vehicle. Be sure to consider this when determining the
depth and the ability to safely cross.
CROSSING PUDDLES, POOLS, FLOODED
AREAS OR OTHER STANDING WATER
Puddles, pools, flooded or other standing water areas
normally contain murky or muddy waters. These water
types normally contain hidden obstacles and make it
difficult to determine an accurate water depth, approach
angle, and bottom condition. Murky or muddy water holes
are where you want to hook up tow straps prior to entering.
This makes for a faster, cleaner and easier vehicle
recovery. If you are able to determine you can safely cross,
than proceed using the low and slow method.
WARNING!
Driving across an incline increases the risk of a rollover,
which may result in severe injury.
WARNING!
If the engine stalls or you lose headway or cannot make
it to the top of a steep hill or grade, never attempt to
turn around. To do so may result in tipping and rolling
the vehicle, which may result in severe injury. Always
back carefully straight down a hill in REVERSE. Never
back down a hill in NEUTRAL using only the vehicle
brakes. Never drive diagonally across a hill, always drive
straight up or down.
CAUTION!
Water ingestion into the axles, transmission, transfer
case, engine or vehicle interior can occur if you drive
too fast or through too deep of water. Water can
cause permanent damage to engine, driveline or
other vehicle components, and your brakes will be
less effective once wet and/or muddy.
 When driving through water, do not exceed 5 mph
(8 km/h). Always check water depth before entering
as a precaution, and check all fluids afterward.
Driving through water may cause damage that may
not be covered by the New Vehicle Limited Warranty.
CAUTION!
Muddy waters can reduce the cooling system
effectiveness by depositing debris onto the radiator.

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290SAFETY
PERIODIC SAFETY CHECKS YOU SHOULD
M
AKE 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 lug nut/bolt torque 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 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.
EXHAUST GAS
The best protection against carbon monoxide entry into
the vehicle body is a properly maintained 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 an authorized dealer inspect the complete
exhaust system and adjacent body areas for broken,
damaged, deteriorated, or mispositioned parts. Open seams or loose connections could permit exhaust fumes
to seep into the passenger compartment. In addition,
inspect the exhaust system each time the vehicle is raised
for lubrication or oil change. Replace as required.
CARBON MONOXIDE WARNINGS
WARNING!
Exhaust gases can injure or kill. They contain carbon
monoxide (CO), which is colorless and odorless.
Breathing it can make you unconscious and can
eventually poison 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.
 If you are required to drive with the trunk/liftgate/
rear doors open, make sure that all windows are
closed and the climate control BLOWER switch is set
at high speed. DO NOT use the recirculation mode.
 If it is necessary to sit in a parked vehicle with the
engine running, adjust your heating or cooling
controls to force outside air into the vehicle. Set the
blower at high speed.
WARNING!
Carbon monoxide (CO) in exhaust gases is deadly.
Follow the precautions below to prevent carbon
monoxide poisoning:
Do not inhale exhaust gases. They contain carbon
monoxide, a colorless and odorless gas, which can
kill. Never run the engine in a closed area, such as a
garage, and never sit in a parked vehicle with the
engine running for an extended period. If the vehicle
is stopped in an open area with the engine running
for more than a short period, adjust the ventilation
system to force fresh, outside air into the vehicle.
 Guard against carbon monoxide with proper mainte -
nance. Have the exhaust system inspected every
time the vehicle is raised. Have any abnormal condi -
tions repaired promptly. Until repaired, drive with all
side windows fully open.
 When exiting the vehicle, always make sure the igni -
tion is in the OFF position, remove the key fob from
the vehicle and lock your vehicle.

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IN CASE OF EMERGENCY299

Positive (+) Battery Post – Diesel Engine

NOTE:The positive (+) battery post is covered with a protective
cap. Lift up on the cap to gain access to the post.
If your vehicle is equipped with a Stop/Start system, it will
be equipped with two batteries
Úpage 147.
See the following steps to prepare for jump starting:

1. Apply the parking brake, shift the automatic transmission into PARK (P) (manual transmission in
NEUTRAL) and turn the ignition OFF.

2. Turn off the heater, radio, and all electrical accessories.
3. Pull upward and remove the protective cover over the positive (+) battery post.
4. 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.
JUMP STARTING PROCEDURE
Connecting The Jumper Cables

1. Connect the positive
(+) end of the jumper cable to
the positive (+)
post of the discharged vehicle.

2. Connect the opposite end of the positive (+) jumper
cable to the positive (+) post of the booster battery.
3. Connect the negative (-) end of the jumper cable to
the negative (-) post of the booster battery.
4. Connect the opposite end of the negative (-) jumper
cable to a good engine ground. A “ground” is an
exposed metallic/unpainted part of the engine, frame
or chassis, such as an accessory bracket or large bolt.
The ground must be away from the battery and the
fuel injection system.

Jump Starting Label

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.
WARNING!
Do not allow vehicles to touch each other as this could
establish a ground connection and personal injury
could result.
WARNING!
Failure to follow this jump starting procedure could
result in personal injury or property damage due to
battery explosion.
WARNING!
Do not connect the jumper cable to the negative (-) post
of the discharged battery. The resulting electrical spark
could cause the battery to explode and could result in
personal injury.
7

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300IN CASE OF EMERGENCY
5. Start the engine in the vehicle that has the booster
battery, let the engine idle a few minutes, and then
start the engine in the vehicle with the discharged
battery.
6. Once the engine is started, remove the jumper cables in the reverse sequence.
Disconnecting The Jumper Cables

1. Disconnect the negative
(-)
end of the jumper cable
from the engine ground of the vehicle with the
discharged battery.

2. Disconnect the opposite end of the negative (-)
jumper cable from the negative (-) post of the booster
battery.
3. Disconnect the positive (+) end of the jumper cable
from the positive (+) post of the booster battery. 4. Disconnect the opposite end of the positive
(+)
jumper cable from the positive (+) post of the
discharged vehicle.
5. Reinstall the protective cover over the positive (+)
post of the discharged vehicle.
NOTE:If frequent jump starting is required to start your vehicle
you should have the battery and charging system tested at
an authorized dealer.
IF YOUR ENGINE OVERHEATS
If the vehicle is overheating, it will need to be serviced by
an authorized dealer.
Potential signs of vehicle overheating:
 Temperature gauge is at HOT (H)
 Strong smell of coolant
 White smoke coming from engine or exhaust
 Coolant bottle coolant has bubbles present In the event it is observed that the temperature gauge is
moving towards or close to the HOT (H) position, you can
reduce the potential for overheating by taking the
appropriate action.

On the highways — slow down.
 In city traffic — while stopped, place the transmission in
NEUTRAL (N), but do not increase the engine idle speed
while preventing vehicle motion with the brakes.
 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.
CAUTION!
Make sure at all times that unused ends of jumper
cables are not contacting each other or either vehicle
while making connections. Failure to follow these
procedures could result in damage to the charging
system of the booster vehicle or the discharged vehicle.
CAUTION!

Do not run the booster vehicle engine above 2,000 RPM
since it provides no charging benefit, wastes fuel, and
can damage booster vehicle engine.

CAUTION!
Accessories plugged into the vehicle power outlets draw
power from the vehicle’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 discharge sufficiently to degrade battery life and/or
prevent the engine from starting.
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.

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IN CASE OF EMERGENCY301
MANUAL PARK RELEASE
In order to move the vehicle in cases where the
transmission will not shift out of PARK (P) (such as a
depleted battery), a Manual Park Release is available. See the following steps to use the Manual Park Release:

1. Firmly apply the parking brake.

2. Using a small screwdriver or similar tool, remove the
manual park release cover located in front of the gear
selector, to access the release tether strap.

Manual Park Release Cover

3. Fish the tether strap up through the opening in the console base.

Tether Strap

4. Press and maintain firm pressure on the brake pedal.
5. Pull the tether strap up until the release lever locks into place in the vertical position. The vehicle is now
out of PARK (P) and can be moved. Release the
parking brake only when the vehicle is securely
connected to a tow vehicle.

Vertical Released Position

CAUTION!
Driving with a hot cooling system could damage your
vehicle. If the temperature gauge reads “H,” pull over
and stop the vehicle. Idle the vehicle with the air condi -
tioner turned off until the pointer drops back into the
normal range. If the pointer remains on the “H” and you
hear continuous chimes, turn the engine off immedi -
ately and call for service.
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.
7

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SERVICING AND MAINTENANCE307
MAINTENANCE PLAN
Refer to the maintenance plan for the required maintenance intervals.
NOTE:Using white lithium grease, lubricate the door hinge joints twice a year to prevent premature wear.
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 parking brake.
 Inspect engine cooling system protection and hoses.
 Inspect exhaust system.
 Inspect engine air cleaner filter if using in dusty or off-road conditions; replace engine air cleaner filter if necessary.
 Inspect all door latches for presence of grease; reapply if necessary.
8

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SERVICING AND MAINTENANCE311
MAINTENANCE PLAN — DIESEL FUEL UP TO B5 BIODIESEL
Refer to the maintenance plan for the required maintenance intervals.
At Every Oil Change Interval As Indicated By Oil Change Indicator System
Change oil and filter.
 Completely fill the Diesel Exhaust Fluid tank.
 Drain water from fuel filter assembly.
 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 parking brake.
 Inspect engine cooling system protection and hoses.
 Inspect exhaust system.
 Inspect engine air cleaner filter if using in dusty or off-road conditions; replace engine air cleaner filter if necessary.
At Every Second Oil Change Interval As Indicated By Oil Change Indicator System
Change fuel filter.8

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324SERVICING AND MAINTENANCE
reacts with engine exhaust in the presence of a catalyst to
convert smog-forming Nitrogen Oxides (NOx) into
harmless nitrogen and water vapor.
For further information
Úpage 374.
ACCESSORY DRIVE BELT INSPECTION
When inspecting accessory drive belts, small cracks that
run across the ribbed surface of the belt, from rib to rib,
are considered normal. These are not a reason to replace
a belt. However, cracks running along a rib (not across) are
not normal. Any belt with cracks running along a rib must
be replaced. Also have the belt replaced if it has excessive
wear, frayed cords, or severe glazing.

Accessory Belt (Serpentine Belt)

Conditions that would require replacement:
Rib chunking (one or more ribs has separated from belt
body)
 Rib or belt wear
 Longitudinal belt cracking (cracks between two ribs)
 Belt slips
 Groove jumping (belt does not maintain correct posi -
tion on pulley)
 Belt broken
 Noise (objectionable squeal, squeak, or rumble is
heard or felt while drive belt is in operation)
NOTE:Identify and correct problem before new belt is installed.
Some conditions can be caused by a faulty component
such as a belt pulley. Belt pulleys should be carefully
inspected for damage and proper alignment.
Belt replacement on some models requires the use of
special tools, we recommend having your vehicle serviced
at an authorized dealer.
AIR CONDITIONER MAINTENANCE
For best possible performance, your air conditioner should
be checked and serviced by an authorized dealer at the
start of each warm season. This service should include
cleaning of the condenser fins and a performance test.
Drive belt tension should also be checked at this time.
WARNING!
Do not attempt to inspect an accessory drive belt
with the vehicle running.
 When working near the radiator cooling fan, discon -
nect the fan motor lead. The fan is temperature
controlled and can start at any time regardless of
ignition mode. You could be injured by the moving
fan blades.
 You can be badly injured working on or around a
motor vehicle. Only do service work for which you
have the knowledge and the proper equipment. If
you have any doubt about your ability to perform a
service job, take your vehicle to a competent
mechanic.WARNING!
Use only refrigerants and compressor lubricants
approved by the manufacturer for your air condi -
tioning system. Some unapproved refrigerants are
flammable and can explode, injuring you. Other
unapproved refrigerants or lubricants can cause the
system to fail, requiring costly repairs. Refer to
Warranty Information Book, located in your owner’s
information kit, for further warranty information.
 The air conditioning system contains refrigerant
under high pressure. To avoid risk of personal injury
or damage to the system, adding refrigerant or any
repair requiring lines to be disconnected should be
done by an experienced technician.
CAUTION!
Do not use chemical flushes in your air conditioning
system as the chemicals can damage your air
conditioning components. Such damage is not covered
by the New Vehicle Limited Warranty.

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