2023 JEEP WRANGLER engine

168STARTING AND OPERATING
System Overview
This vehicle is equipped with a Diesel Exhaust Fluid (DEF)
injection system and a Selective Catalytic Reduction (SCR)
catalyst to meet the emission requirements.
The DEF injection system consists of the following
components:
DEF tank
 DEF pump
 DEF injector
 Electronically-heated DEF Lines
 NOx sensors
 Temperature sensors
 SCR catalyst
The DEF injection system and SCR catalyst enable the
achievement of diesel emission requirements; while
maintaining outstanding fuel economy, drivability, torque
and power ratings.
For system messages and warnings see
Úpage 108.
NOTE:
 Your vehicle is equipped with a DEF injection system.
You may occasionally hear an audible clicking noise
from under the vehicle at a stop. This is normal opera -
tion.
 The DEF pump will run for a period of time after engine
shutdown to purge the DEF system. This is normal
operation and may be audible from the rear of the
vehicle.
Diesel Exhaust Fluid Storage
Diesel Exhaust Fluid (DEF) is considered a very stable
product with a long shelf life. If DEF is kept in
temperatures between 10° and 90°F (-12° and 32°C), it
will last a minimum of one year.
DEF is subject to freezing at the lowest temperatures. For
example, DEF may freeze at temperatures at or below
12°F (-11°C). The system has been designed to operate
in this environment.
NOTE:When working with DEF, it is important to know that:
Any containers or parts that come into contact with DEF
must be DEF compatible (plastic or stainless steel).
Copper, brass, aluminum, iron or non-stainless steel
should be avoided as they are subject to corrosion by
DEF.
 If DEF is spilled, it should be wiped up completely.
Adding Diesel Exhaust Fluid
The DEF gauge (located on the instrument cluster display)
will display the level of DEF remaining in the tank
Úpage 108.
NOTE:Driving conditions (altitude, vehicle speed, load, etc.) will
affect the amount of DEF that is used in your vehicle.
DEF FILL PROCEDURE
NOTE:
For the correct DEF fluid type see Úpage 374.

1. Remove cap from DEF fill inlet (located in fuel door).

Fuel and Diesel Exhaust Fluid Fill Location

2. Insert DEF fill adapter/nozzle into DEF fill inlet.
NOTE:
 The DEF gauge may take up to five seconds to
update after adding a gallon or more of Diesel
Exhaust Fluid (DEF) to the DEF tank. If you have a
fault related to the DEF system, the gauge may not
update to the new level. See an authorized dealer
for service.
 The DEF gauge may also not immediately update
after a refill if the temperature of the DEF fluid is
below 12°F (-11°C). The DEF tank heater will
1 — Diesel Fuel Filler
2 — Diesel Exhaust Fluid Filler

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STARTING AND OPERATING169
possibly warm up the DEF fluid and allow the
gauge to update after a period of run time. Under
very cold conditions, it is possible that the gauge
may not reflect the new fill level for several drives.
 Excessive overfilling of the DEF tank can result in
a MIL lamp/fault code and inaccurate level read -
ings.
Refilling With Nozzles
You can fill up at any DEF distributor.
Proceed as follows:
 Insert the DEF nozzle in the filler, start refilling and
stop refilling at the first shut-off (the shut-off indi -
cates that the DEF tank is full). Do not proceed
with the refilling, to prevent spillage of DEF.
 Extract the nozzle.
Refilling With Containers
Proceed as follows:
 Check the expiration date.
 Read the advice for use on the label before
pouring the content of the bottle into the DEF tank.
 If systems which cannot be screwed in (e.g. tanks)
are used for refilling, after the indication appears
on the instrument panel display
Úpage 104 fill
the DEF tank with no more than 2 gal (8 L).
 If containers which can be screwed to the filler are
used, the reservoir is full when the DEF level in the
container stops pouring out. Do not proceed
further. 3. Stop filling the DEF tank immediately when any of the
following happen: DEF stops flowing from the fill
bottle into the DEF fill inlet, DEF splashes out the fill
inlet, or a DEF pump nozzle automatically shuts off.
4. Reinstall cap onto DEF fill inlet.
VEHICLE LOADING
CERTIFICATION LABEL
As required by National Highway Traffic Safety
Administration regulations, your vehicle has a certification
label affixed to the driver's side door or pillar.
This label contains the month and year of manufacture,
Gross Vehicle Weight Rating (GVWR), Gross Axle Weight
Rating (GAWR) front and rear, and Vehicle Identification
Number (VIN). A Month-Day-Hour (MDH) number is
included on this label and indicates the Month, Day and
Hour of manufacture. The bar code that appears on the
bottom of the label is your VIN.
Gross Vehicle Weight Rating (GVWR)
The GVWR is the total permissible weight of your vehicle
including driver, passengers, vehicle, options and cargo.
The label also specifies maximum capacities of front and
rear axle systems (GAWR). Total load must be limited so
GVWR and front and rear GAWR are not exceeded.
CAUTION!
 To avoid DEF spillage, and possible damage to the
DEF tank from overfilling, do not “top off” the DEF
tank after filling.
 DO NOT OVERFILL. DEF will freeze below 12ºF
(-11ºC). The DEF system is designed to work in
temperatures below the DEF freezing point, however,
if the tank is overfilled and freezes, the system could
be damaged.
 When DEF is spilled, clean the area immediately with
water and use an absorbent material to soak up the
spills on the ground.
 Do not attempt to start your engine if DEF is acciden -
tally added to the diesel fuel tank as it can result in
severe damage to your engine, including but not
limited to failure of the fuel pump and injectors.
 Never add anything other than DEF to the tank –
especially any form of hydrocarbon such as diesel
fuel, fuel system additives, gasoline, or any other
petroleum-based product. Even a very small amount
of these, less than 100 parts per million or less than
1 oz. per 78 gal (295 L) will contaminate the entire
DEF system and will require replacement. If owners
use a container, funnel or nozzle when refilling the
tank, it should either be new or one that has only
been used for adding DEF. Mopar® provides an
attachable nozzle with its DEF for this purpose.
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172STARTING AND OPERATING
TRAILER HITCH CLASSIFICATION
The following chart provides the industry standard for the maximum trailer weight a given trailer hitch class can tow and should be used to assist you in selecting the correct trailer hitch
for your intended towing condition.
TRAILER TOWING WEIGHTS (MAXIMUM TRAILER WEIGHT RATINGS)
NOTE:The trailer tongue weight must be considered as part of the combined weight of occupants and cargo (i.e., the GVWR), and the GVWR should never exceed the weight referenced on
the Tire And Loading Information Placard Úpage 345.
Trailer Hitch Classification Definitions
Class Max. Trailer Hitch Industry Standards
Class I - Light Duty 2,000 lb (907 kg)
Class II - Medium Duty 3,500 lb (1,587 kg)
Class III - Heavy Duty 6,000 lb (2,721 kg)
Class IV - Extra Heavy Duty 10,000 lb (4,535 kg)
Refer to the “Trailer Towing Weights (Maximum Trailer Weight Ratings)” chart for the Maximum Gross Trailer Weight (GTW) towable for your given drivetrain.
All trailer hitches should be professionally installed on your vehicle.
Engine/Transmission Model GCWRFrontal Area Maximum GTW Maximum Trailer TW
(See Note)
2.0L Two–Door
8,016 lb (3,636 kg) 20 ft2 (1.86 m2) 2,000 lb (907 kg)200 lb (91 kg)
Four–Door 8,117 lb (3,682 kg) 30 ft2 (2.79 m2) 3,500 lb (1,587 kg)350 lb (158 kg)
3.6L Two–Door
8,016 lb (3,636 kg) 20 ft2 (1.86 m2) 2,000 lb (907 kg)200 lb (91 kg)
Four–Door 8,117 lb (3,682 kg) 30 ft2 (2.79 m2) 3,500 lb (1,587 kg)350 lb (158 kg)
3.0L Diesel Four–Door8,427 lb (3,822 kg) 30 ft2 (2.79 m2) 3,500 lb (1,587 kg)350 lb (158 kg)
Refer to local laws for maximum trailer towing speeds.

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STARTING AND OPERATING173
(Continued)
TRAILER AND TONGUE WEIGHT
Never exceed the maximum tongue weight stamped on
your bumper or trailer hitch.

Weight Distribution

Consider the following items when computing the weight
on the rear axle of the vehicle:
The tongue weight of the trailer.
 The weight of any other type of cargo or equipment put
in or on your vehicle.
 The weight of the driver and all passengers.
NOTE:Remember that everything put into or on the trailer adds
to the load on your vehicle. Also, additional
factory-installed options or dealer-installed options must
be considered as part of the total load on your vehicle.
Refer to the Tire And Loading Information Placard for the
maximum combined weight of occupants and cargo for
your vehicle.
TOWING REQUIREMENTS
To promote proper break-in of your new vehicle drivetrain
components, the following guidelines are recommended:
WARNING!
Improper towing can lead to a collision. Follow these
guidelines to make your trailer towing as safe as
possible:
Make certain that the load is secured in the trailer
and that it will not shift during travel. When trailering
cargo that is not fully secured, dynamic load shifts
can occur that may be difficult for the driver to
control. You could lose control of your vehicle and
have a collision.
 When hauling cargo, or towing a trailer, do not over -
load your vehicle or trailer. Overloading can cause a
loss of control, poor performance, or damage to
brakes, axle, engine, transmission, steering, suspen -
sion, chassis structure, or tires.
 Safety chains must always be used between your
vehicle and trailer. Always connect the chains to the
frame or hook retainers of the vehicle hitch. Cross
the chains under the trailer tongue and allow enough
slack for turning corners.
Vehicles with trailers should not be parked on a
grade. When parking, apply the parking brake on the
tow vehicle. Put the tow vehicle transmission in
PARK. Always block or "chock" the trailer wheels.
 GCWR must not be exceeded.
 Total weight must be distributed between the tow
vehicle and the trailer such that the following four
ratings are not exceeded:
 GVWR
 GTW
 GAWR
 Tongue weight rating for the trailer hitch utilized
CAUTION!
Do not tow a trailer at all during the first 500 miles
(805 km) the new vehicle is driven. The engine, axle
or other parts could be damaged.
 Then, during the first 500 miles (805 km) that a
trailer is towed, do not drive over 50 mph (80 km/h)
and do not make starts at full throttle. This helps the
engine and other parts of the vehicle wear in at the
heavier loads.
WARNING!
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STARTING AND OPERATING175

Seven-Pin Connector

TOWING TIPS
Before setting out on a trip, practice turning, stopping and
backing the trailer in an area away from heavy traffic.
If using a manual transmission vehicle for trailer towing,
all starts must be in FIRST gear to avoid excessive clutch
slippage.
Automatic Transmission — If Equipped
Select the DRIVE range when towing. The transmission
controls include a drive strategy to avoid frequent shifting
when towing. However, if frequent shifting does occur
while in DRIVE, you can use the AutoStick shift control to
manually select a lower gear.
NOTE:Using a lower gear while operating the vehicle under heavy
loading conditions, will improve performance and extend
transmission life by reducing excessive shifting and heat
buildup. This action will also provide better engine
braking.
AutoStick — If Equipped
When using the AutoStick shift control, select the
highest gear that allows for adequate performance and
avoids frequent downshifts. For example, choose “5” if
the desired speed can be maintained. Choose “4” or
“3” if needed to maintain the desired speed.
 To prevent excess heat generation, avoid continuous
driving at high RPM. Return to a higher gear or vehicle
speed when grade and road conditions allow.
Cruise Control — If Equipped
Do not use in hilly terrain or with heavy loads.
 When using the Cruise Control, if you experience speed
drops greater than 10 mph (16 km/h), disengage until
you can get back to cruising speed.
 Use Cruise Control in flat terrain and with light loads to
maximize fuel efficiency.
1 — Backup Lamps
2 — Running Lamps
3 — Left Stop/Turn
4 — Ground
5 — Battery
6 — Right Stop/Turn
7 — Electric Brakes4

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STARTING AND OPERATING177
Shifting Into (N) Neutral
Use the following procedure to prepare your vehicle for
recreational towing:

1. Bring the vehicle to a complete stop on level ground.

2. Press and hold the brake pedal. 3. Shift the automatic transmission into NEUTRAL or
press the clutch pedal on a manual transmission.
4. Turn the engine off.
5. Shift the transfer case lever into (N) Neutral.
6. Start the engine.
7. Shift the transmission into REVERSE.
8. Release the brake pedal (and clutch pedal on manual transmissions) for five seconds and ensure that there
is no vehicle movement.
9. Repeat steps seven and eight with automatic transmission in DRIVE or manual transmission in
FIRST gear.
10. Turn the engine off.
11. Firmly apply the parking brake.
12. Shift the transmission into PARK or place manual transmission in gear (NOT in NEUTRAL).
13. Attach the vehicle to the tow vehicle using a suitable tow bar.
14. Release the parking brake.
Shifting Out of (N) Neutral
Use the following procedure to prepare your vehicle for
normal usage.

1. Bring the vehicle to a complete stop, leaving it connected to the tow vehicle.

2. Firmly apply the parking brake.
3. Start the engine.
4. Press and hold the brake pedal.
5. Shift the transmission into NEUTRAL.
6. Turn the engine off.
7. Shift the transfer case lever to the desired position.
NOTE:When shifting the transfer case out of (N) Neutral, the
engine should remain off to avoid gear clash.
8. Shift the automatic transmission into PARK, or place manual transmission in NEUTRAL.
9. Release the brake pedal.
10. Disconnect vehicle from the tow vehicle.
11. Start the engine.
12. Press and hold the brake pedal.
13. Release the parking brake.
14. Shift the transmission into gear, release the brake pedal (and clutch pedal on manual transmissions),
and check that the vehicle operates normally.

Do not use a fascia/bumper-mounted clamp-on tow
bar on your vehicle. The bumper face bar will be
damaged.
WARNING!
You or others could be injured or killed if you leave the
vehicle unattended with the transfer case in the (N)
Neutral position without first fully engaging the parking
brake. The transfer case (N) Neutral position
disengages both the front and rear driveshafts from the
powertrain, and will allow the vehicle to roll, even if the
automatic transmission is in PARK (or manual
transmission is in gear). The parking brake should
always be applied when the driver is not in the vehicle.
CAUTION!
It is necessary to follow these steps to be certain that
the transfer case is fully in (N) Neutral before
recreational towing to prevent damage to internal parts.
CAUTION!
CAUTION!
Damage to the transmission may occur if the
transmission is shifted into PARK with the transfer case
in (N) Neutral and the engine running. With the transfer
case in (N) Neutral ensure that the engine is OFF before
shifting the transmission into PARK.
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STARTING AND OPERATING179
(Continued)
The Basics Of Off-Road Driving
You will encounter many types of terrain driving off-road.
You should be familiar with the terrain and area before
proceeding. There are many types of surface conditions:
hard-packed dirt, gravel, rocks, grass, sand, mud, snow
and ice. Every surface has a different effect on your
vehicle's steering, handling and traction. Controlling your
vehicle is one of the keys to successful off-road driving, so
always keep a firm grip on the steering wheel and
maintain a good driving posture. Avoid sudden
accelerations, turns or braking. In most cases, there are
no road signs, posted speed limits or signal lights.
Therefore, you will need to use your own good judgment on
what is safe and what is not. When on a trail, you should
always be looking ahead for surface obstacles and
changes in terrain. The key is to plan your future driving
route while remembering what you are currently driving
over.
NOTE:It is recommended that the Stop/Start system and the
Forward Collision Warning (FCW) system (if equipped) be
disabled during off-road use.
When To Use 4L Range
When off-road driving, shift into 4L for additional traction
and control on slippery or difficult terrain, ascending or
descending steep hills, and to increase low speed pulling
power. This range should be limited to extreme situations
such as deep snow, mud, steep inclines, or sand where
additional low speed pulling power is needed. Vehicle
speeds in excess of 25 mph (40 km/h) should be avoided
when in 4L.
Simultaneous Brake And Throttle
Operation
Many off-road driving conditions require the simultaneous
use of the brake and throttle (two-footed driving). When
climbing rocks, logs, or other stepped objects, using light
brake pressure with light throttle will keep the vehicle from
jerking or lurching. This technique is also used when you
need to stop and restart a vehicle on a steep incline.
Driving In Snow, Mud And Sand
SNOW
In heavy snow or for additional control and traction at
slower speeds, shift the transmission into a low gear and
the transfer case into 4L if necessary. Do not shift to a
lower gear than necessary to maintain headway.
Over-revving the engine can spin the wheels and traction
will be lost. If you start to slow to a stop, try turning your
steering wheel no more than a 1/4 turn quickly back and
forth, while still applying throttle. This will allow the tires to
get fresh traction and help maintain your momentum.
MUD
Deep mud creates a great deal of suction around the tires
and is very difficult to get through. You should use DRIVE,
with the transfer case in the 4L position to maintain your
momentum. If you start to slow to a stop, try turning your
steering wheel no more than a 1/4 turn quickly back and
forth for additional traction. Mud holes pose an increased
threat of vehicle damage and getting stuck. They are
normally full of debris from previous vehicles getting
stuck. As a good practice before entering any mud hole,
get out and determine how deep it is, if there are any
hidden obstacles and if the vehicle can be safely
recovered if stuck.
WARNING!
 Always wear your seat belt and firmly tie down cargo.
Unsecured cargo can become projectiles in an
off-road situation.
A malfunctioning catalytic converter can reach higher
temperatures than in normal operating conditions.
This can cause a fire if you drive slowly or park over
flammable substances such as dry plants, wood,
cardboard, etc. This could result in death or serious
injury to the driver, occupants or others.
CAUTION!
Do not use 4L when operating the vehicle on dry
pavement. Driveline hardware damage can result.
WARNING!
CAUTION!
On icy or slippery roads, do not downshift at high engine
RPM or vehicle speeds, because engine braking may
cause skidding and loss of control.
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STARTING AND OPERATING181
GETTING HIGH-CENTERED
If you get hung up or high-centered on an object, get out of
the vehicle and try to determine what the vehicle is hung
up on, where it is contacting the underbody and what is
the best direction to recover the vehicle. Depending on
what you are in contact with, jack the vehicle up and place
a few rocks under the tires so the weight is off of the high
point when you let the vehicle down. You can also try
rocking the vehicle or winching the vehicle off the object.
Hill Climbing
Hill climbing requires good judgment and a good
understanding of your abilities and your vehicle's
limitations. Hills can cause serious problems. Some are
just too steep to climb and should not be attempted. You
should always feel confident with the vehicle and your
abilities. You should always climb hills straight up and
down. Never attempt to climb a hill on an angle.
BEFORE CLIMBING A STEEP HILL
As you approach a hill, consider its grade or steepness.
Determine if it is too steep. Look to see what the traction
is on the hill side trail. Is the trail straight up and down?
What is on top and the other side? Are there ruts, rocks,
branches or other obstacles on the path? Can you safely
recover the vehicle if something goes wrong? If everything
looks good and you feel confident, shift the transmission
into a lower gear with 4L engaged, and proceed with
caution, maintaining your momentum as you climb the hill.
DRIVING UP HILL
Once you have determined your ability to proceed and
have shifted into the appropriate gear, line your vehicle up
for the straightest possible run. Accelerate with an easy
constant throttle and apply more power as you start up the
hill. Do not race forward into a steep grade; the abrupt
change of grade could cause you to lose control. If the
front end begins to bounce, ease off the throttle slightly to
bring all four tires back on the ground. As you approach
the crest of the hill, ease off the throttle and slowly
proceed over the top. If the wheels start to slip as you
approach the crest of a hill, ease off the accelerator and
maintain headway by turning the steering wheel no more
than a 1/4 turn quickly back and forth. This will provide a
fresh "bite" into the surface and will usually provide
enough traction to complete the climb. If you do not make
it to the top, place the vehicle in REVERSE and back
straight down the grade using engine resistance along
with the vehicle brakes.
DRIVING DOWNHILL
Before driving down a steep hill, you need to determine if
it is too steep for a safe descent. What is the surface
traction? Is the grade too steep to maintain a slow,
controlled descent? Are there obstacles? Is it a straight
descent? Is there plenty of distance at the base of the hill
to regain control if the vehicle descends to fast? If you feel
confident in your ability to proceed, then make sure you
are in 4L and proceed with caution. Allow engine braking
to control the descent and apply your brakes, if necessary,
but do not allow the tires to lock.
CAUTION!
Do not attempt to cross a log with a greater diameter
than the running ground clearance or the vehicle will
become high-centered.
CAUTION!
Winching or rocking the vehicle off hard objects
increases the risk of underbody damage.
WARNING!
Never attempt to climb a hill at an angle or turn around
on a steep grade. Driving across an incline increases
the risk of a rollover, which may result in severe injury.
WARNING!
Do not descend a steep grade in NEUTRAL. Use vehicle
brakes in conjunction with engine braking. Descending
a grade too fast could cause you to lose control and be
seriously injured or killed.
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