2023 JEEP WRANGLER warning

166STARTING AND OPERATING
(Continued)
4. Fill the vehicle with fuel.
NOTE:

When the fuel nozzle “clicks” or shuts off, the fuel
tank is full.
 Wait five seconds before removing the fuel nozzle
to allow excess fuel to drain from the nozzle.
5. Remove the fuel nozzle, reinstall fuel cap and close fuel filler door.
NOTE:
When the fuel nozzle “clicks” or shuts off, the fuel tank
is full.
 Tighten the fuel filler cap about a quarter turn until you
hear one click. This is an indication that the cap is prop -
erly tightened.
 If the fuel filler cap is not tightened properly, the MIL
will come on. Be sure the cap is tightened every time
the vehicle is refueled.
LOOSE FUEL FILLER CAP MESSAGE
After fuel has been added, the vehicle diagnostic system
can determine if the fuel filler cap is possibly loose,
improperly installed, or damaged. If the system detects a
malfunction, the “gASCAP” message will display in the
odometer display. Tighten the gas cap until a "clicking"
sound is heard. This is an indication that the gas cap is
properly tightened. Push the odometer reset button to turn
the message off. If the problem persists, the message will
appear the next time the vehicle is started. This might
indicate a damaged cap. If the problem is detected twice
in a row, the system will turn on the MIL. Resolving the
problem will turn the MIL off.
REFUELING THE VEHICLE — DIESEL ENGINE
(IF EQUIPPED)
The fuel filler cap is located on the driver's side of the
vehicle. If the fuel filler cap is lost or damaged, be sure the
replacement cap is the correct one for this vehicle.

1. Open the fuel filler door.

Fuel Filler Door

WARNING!

Never have any smoking materials lit in or near the
vehicle when the fuel door is open or the tank is being
filled.
 Never add fuel when the engine is running. This is in
violation of most state and federal fire regulations and
may cause the Malfunction Indicator Light to turn on.
 A fire may result if fuel is pumped into a portable
container that is inside of a vehicle. You could be
burned. Always place fuel containers on the ground
while filling.

CAUTION!
Damage to the fuel system or emission control
system could result from using an improper fuel filler
cap. A poorly fitting cap could let impurities into the
fuel system. Also, a poorly fitting aftermarket cap can
cause the Malfunction Indicator Light (MIL) to illumi -
nate, due to fuel vapors escaping from the system.
 To avoid fuel spillage and overfilling, do not “top off”
the fuel tank after filling.
CAUTION!

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STARTING AND OPERATING167
2. Remove the fuel cap by rotating it counterclockwise.

Fuel and Diesel Exhaust Fluid (DEF) Fill Location

3. Fully insert the fuel nozzle into the filler pipe.
4. Fill the vehicle with fuel.
NOTE:
When the fuel nozzle “clicks” or shuts off, the fuel
tank is full.
 Wait five seconds before removing the fuel nozzle
to allow excess fuel to drain from the nozzle.
5. Remove the fuel nozzle, reinstall fuel cap and close fuel filler door.
NOTE:Tighten the fuel filler cap about a quarter turn until you
hear one click. This is an indication that the cap is properly
tightened.
AVOID USING CONTAMINATED FUEL
Fuel that is contaminated by water or dirt can cause
severe damage to the engine fuel system. Proper
maintenance of the engine fuel filter and fuel tank is
essential see
Úpage 321.
BULK FUEL STORAGE — DIESEL FUEL
If you store quantities of fuel, good maintenance of the
stored fuel is also essential. Fuel contaminated with water
will promote the growth of “microbes.” These microbes
form “slime” that will clog the fuel filtration system and
lines. Drain condensation from the supply tank and
change the line filter on a regular basis.
NOTE:When a diesel engine is allowed to run out of fuel, air is
pulled into the fuel system.
If the vehicle will not start see
Úpage 323.
DIESEL EXHAUST FLUID
Your vehicle is equipped with a Selective Catalytic
Reduction (SCR) system to meet the very stringent diesel
emissions standards required by the Environmental
Protection Agency.
The purpose of the SCR system is to reduce levels of NOx
(oxides of nitrogen emitted from engines) that are harmful
to our health and the environment to a near-zero level. A
small quantity of Diesel Exhaust Fluid (DEF) is injected into
the exhaust upstream of a catalyst where, when
vaporized, it converts smog-forming nitrogen oxides (NOx)
into harmless nitrogen (N2) and water vapor (H2O), two
natural components of the air we breathe. You can
operate with the comfort that your vehicle is contributing
to a cleaner, healthier world environment for this and
generations to come.
1 — Diesel Fuel Filler
2 — DEF Filler
CAUTION!
For diesel engines, only use diesel fuel for motor
vehicles in accordance with ASTM D-975 Grade S15
specifications. The use of other products or mixtures
may damage the engine beyond repair and
consequently void the warranty, due to the damage
caused. If you accidentally introduce other types of fuel
into the tank, do not start the engine. Empty the tank. If
the engine has been run for even an extremely limited
amount of time, you must not only drain the fuel tank,
but the rest of the supply circuit as well.
WARNING!
Do not open the high pressure fuel system with the
engine running. Engine operation causes high fuel
pressure. High pressure fuel spray can cause serious
injury or death.
4

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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

23_JL_OM_EN_USC_t.book Page 168

170STARTING AND OPERATING
Payload
The payload of a vehicle is defined as the allowable load
weight a truck can carry, including the weight of the driver,
all passengers, options and cargo.
Gross Axle Weight Rating (GAWR)
The GAWR is the maximum permissible load on the front
and rear axles. The load must be distributed in the cargo
area so that the GAWR of each axle is not exceeded.
Each axle GAWR is determined by the components in the
system with the lowest load carrying capacity (axle,
springs, tires or wheels). Heavier axles or suspension
components sometimes specified by purchasers for
increased durability do not necessarily increase the
vehicle's GVWR.
Tire Size
The tire size on the Vehicle Certification Label represents
the actual tire size on your vehicle. Replacement tires
must be equal to the load capacity of this tire size.
Rim Size
This is the rim size that is appropriate for the tire size
listed.
Inflation Pressure
This is the cold tire inflation pressure for your vehicle for
all loading conditions up to full GAWR.
Curb Weight
The curb weight of a vehicle is defined as the total weight
of the vehicle with all fluids, including vehicle fuel, at full
capacity conditions, and with no occupants or cargo
loaded into the vehicle. The front and rear curb weight values are determined by weighing your vehicle on a
commercial scale before any occupants or cargo are
added.
Loading
The actual total weight and the weight of the front and rear
of your vehicle at the ground can best be determined by
weighing it when it is loaded and ready for operation.
The entire vehicle should first be weighed on a commercial
scale to ensure that the GVWR has not been exceeded.
The weight on the front and rear of the vehicle should then
be determined separately to be sure that the load is
properly distributed over the front and rear axle. Weighing
the vehicle may show that the GAWR of either the front or
rear axles has been exceeded but the total load is within
the specified GVWR. If so, weight must be shifted from
front to rear or rear to front as appropriate until the
specified weight limitations are met. Store the heavier
items down low and be sure that the weight is distributed
equally. Stow all loose items securely before driving.
Improper weight distributions can have an adverse effect
on the way your vehicle steers and handles and the way
the brakes operate.
TRAILER TOWING
In this section you will find safety tips and information on
limits to the type of towing you can reasonably do with your
vehicle. Before towing a trailer, carefully review this
information to tow your load as efficiently and safely as
possible.
To maintain the New Vehicle Limited Warranty coverage,
follow the requirements and recommendations in this
manual concerning vehicles used for trailer towing.
COMMON TOWING DEFINITIONS
The following trailer towing related definitions will assist
you in understanding the following information:
Gross Vehicle Weight Rating (GVWR)
The GVWR is the total allowable weight of your vehicle.
This includes driver, passengers, cargo and tongue
weight. The total load must be limited so that you do not
exceed the GVWR
Úpage 169.
Gross Trailer Weight (GTW)
The GTW is the weight of the trailer plus the weight of all
cargo, consumables and equipment (permanent or
temporary) loaded in or on the trailer in its "loaded and
ready for operation" condition.
The recommended way to measure GTW is to put your fully
loaded trailer on a vehicle scale. The entire weight of the
trailer must be supported by the scale.
WARNING!
Do not load your vehicle any heavier than the GVWR or
the maximum front and rear GAWR. If you do, parts on
your vehicle can break, or it can change the way your
vehicle handles. This could cause you to lose control.
Overloading can shorten the life of your vehicle.

23_JL_OM_EN_USC_t.book Page 170

STARTING AND OPERATING171
Gross Combination Weight Rating (GCWR)
The GCWR is the total permissible weight of your vehicle
and trailer when weighed in combination.
Gross Axle Weight Rating (GAWR)
The GAWR is the maximum capacity of the front and rear
axles. Distribute the load over the front and rear axles
evenly. Make sure that you do not exceed either front or
rear GAWR
Úpage 169.
Tongue Weight (TW)
The TW is the downward force exerted on the hitch ball by
the trailer. You must consider this as part of the load on
your vehicle.
Frontal Area
The frontal area is the maximum height multiplied by the
maximum width of the front of a trailer.
Trailer Sway Control (TSC) – If Equipped
The TSC is a telescoping link that can be installed between
the hitch receiver and the trailer tongue. It typically
provides adjustable friction associated with the
telescoping motion to dampen any unwanted trailer
swaying motions while traveling.
Weight-Carrying Hitch
A weight-carrying hitch supports the trailer tongue weight,
just as if it were luggage located at a hitch ball or some
other connecting point of the vehicle. These kinds of
hitches are commonly used to tow small and medium
sized trailers.
Weight-Distributing Hitch
A Weight-Distributing Hitch works by applying leverage
through spring (load) bars. They are typically used for
heavier loads to distribute trailer tongue weight to the tow
vehicle's front axle and the trailer axle(s). When used in
accordance with the manufacturer's directions, it provides
for a more level ride, offering more consistent steering and
brake control thereby enhancing towing safety. The
addition of a friction/hydraulic sway control also dampens
sway caused by traffic and crosswinds and contributes
positively to tow vehicle and trailer stability. Trailer sway control and a Weight-Distributing (load equalizing) Hitch
are recommended for heavier Tongue Weights (TW) and
may be required depending on vehicle and trailer
configuration/loading to comply with Gross Axle Weight
Rating (GAWR) requirements.
WARNING!
It is important that you do not exceed the maximum
front or rear GAWR. A dangerous driving condition can
result if either rating is exceeded.
WARNING!

An improperly adjusted Weight Distributing Hitch
system may reduce handling, stability, braking
performance, and could result in a collision.
 Weight-Distributing Hitch Systems may not be
compatible with surge brake couplers. Consult with
your hitch and trailer manufacturer or a reputable
Recreational Vehicle dealer for additional informa -
tion.
4

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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!
4

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174STARTING AND OPERATING
(Continued)
Towing Requirements — Tires
Proper tire inflation pressures are essential to the safe
and satisfactory operation of your vehicle.
 Check the trailer tires for proper tire inflation pressures
before trailer usage.
 Check for signs of tire wear or visible tire damage
before towing a trailer.
 Replacing tires with a higher load carrying capacity will
not increase the vehicle's GVWR and GAWR limits.
 For further information
Úpage 345.
Towing Requirements — Trailer Brakes
Do not interconnect the hydraulic brake system or
vacuum system of your vehicle with that of the trailer.
This could cause inadequate braking and possible
personal injury.
 An electronically actuated trailer brake controller is
required when towing a trailer with electronically actu -
ated brakes. When towing a trailer equipped with a
hydraulic surge actuated brake system, an electronic
brake controller is not required.
 Trailer brakes are recommended for trailers over 1,000
lb (453 kg) and required for trailers in excess of 2,000
lb (907 kg).
Towing Requirements — Trailer Lights And
Wiring
Whenever you pull a trailer, regardless of the trailer size,
stop lights and turn signals on the trailer are required for
motoring safety.
The Trailer Tow Package may include a four- and seven-pin
wiring harness. Use a factory approved trailer harness and
connector.
NOTE:Do not cut or splice wiring into the vehicle’s wiring
harness. The electrical connections are all complete to the vehicle
but you must mate the harness to a trailer connector.
Refer to the following illustrations.
NOTE:

Disconnect the trailer wiring connector from the vehicle
(or any other device plugged into the vehicle's electrical
connectors) before launching a boat into water.
 Be sure to reconnect once clear from water area.

Four-Pin Connector

WARNING!
Do not connect trailer brakes to your vehicle's
hydraulic brake lines. It can overload your brake
system and cause it to fail. You might not have
brakes when you need them and could have an acci -
dent.
 Towing any trailer will increase your stopping
distance. When towing, you should allow for addi -
tional space between your vehicle and the vehicle in
front of you. Failure to do so could result in an acci -
dent.
CAUTION!
If the trailer weighs more than 1,000 lb (453 kg)
loaded, it should have its own brakes and they should
be of adequate capacity. Failure to do this could lead to
accelerated brake lining wear, higher brake pedal
effort, and longer stopping distances.
WARNING!
1 — Ground
2 — Park
3 — Left Stop/Turn
4 — Right Stop/Turn

23_JL_OM_EN_USC_t.book Page 174

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.
4

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