2021 JEEP WRANGLER UNLIMITED check engine

7
TRAILER TOWING ................................ 175

Trailer Towing Weights
(Maximum Trailer Weight Ratings)..... 175

RECREATIONAL TOWING (BEHIND
MOTORHOME, ETC.) ............................. 176
Towing This Vehicle Behind
Another Vehicle ............................ 176 Recreational Towing — Four-Wheel
Drive Models ................................ 176
IN CASE OF EMERGENCY
HAZARD WARNING FLASHERS............... 179
BULB REPLACEMENT............................ 179
Replacement Bulbs ...................... 179
Bulb Replacement ........................ 181
FUSES ............................................... 183
General Information ...................... 183
Power Distribution Center (PDC) .... 184
JACKING AND TIRE CHANGING .............. 192
Jack Location .............................. 193
Spare Tire Removal ...................... 193
Preparations For Jacking .............. 194
Jacking Instructions ...................... 195
Road Tire Installation.................... 197
Declaration Of Conformance .......... 198
Jack Usage Precautions................. 200
JUMP STARTING .................................. 201
Preparations For Jump Start .......... 201
Jump Starting Procedure ............... 202
IF YOUR ENGINE OVERHEATS ...............204
MANUAL PARK RELEASE .....................204
FREEING A STUCK VEHICLE ..................206
TOWING A DISABLED VEHICLE ..............207
Four–Wheel Drive Models .............. 208
Without The Key Fob .................... 208
Tow Eye Usage............................. 208
ENHANCED ACCIDENT RESPONSE
SYSTEM (EARS) ..................................209
EVENT DATA RECORDER (EDR) ..............209
SERVICING AND MAINTENANCE
SCHEDULED SERVICING .......................210
Scheduled Servicing —
Gasoline Engine ........................... 210 Scheduled Servicing —
Diesel Engine............................... 216
ENGINE COMPARTMENT .......................221
2.0L Gasoline Engine .................. 221
3.6L Gasoline Engine .................. 222
2.2L Diesel Engine ....................... 223
Checking Oil Level —
Gasoline Engine .......................... 224 Adding Washer Fluid .................... 224
Maintenance-Free Battery ............ 225
Pressure Washing ......................... 225
DEALER SERVICE .................................226
Windshield Wiper Blades ...............226
Exhaust System ...........................228
Cooling System .............................229
Brake System ..............................230
Automatic Transmission ................231
RAISING THE VEHICLE ..........................232 TIRES .................................................232
Tires — General Information .........232
Tire Types ....................................237
Spare Tires — If Equipped ............237
Wheel And Wheel Trim Care ..........239

Tire Chains And Traction Devices ..... 240

Tire Rotation Recommendations ....241
STORING THE VEHICLE .........................241
BODYWORK .........................................242
Body And Underbody
Maintenance ................................242 Preserving The Bodywork ...............243
INTERIORS ..........................................245
Seats And Fabric Parts ..................245
Plastic And Coated Parts ...............246
Leather Parts ................................246
Glass Surfaces .............................246
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59
(Continued)

ENVIRONMENTAL PROTECTION
SYSTEMS — IF EQUIPPED

Gasoline Particulate Filter (GPF) — 2.0L T4
Petrol Versions Only
The Gasoline Particulate Filter is a mechan-
ical filter, integral to the exhaust system,
which physically traps carbon particles present in the exhaust gases of 2.0L T4
petrol engines.
The particulate filter is needed to eliminate
almost all carbon particle emissions in
compliance with current/future regulations
and standards.
Since this filter physically traps particulates,
it must be cleaned (regenerated) during
normal driving operation to remove carbon
particles. The regeneration procedure is
controlled automatically by the engine
control unit according to the filter conditions
and car use conditions.
The following may occur during regeneration:
increased levels of noise vibration and
harshness (NVH) and reduced engine
performance.
Dedicated messages can appear in the
instrument cluster display as a result of the
condition of the filter. Refer to the opening
paragraph of the "Warning Lights And
Messages" section for further information.
WARNING!
Cargo must be securely tied down before
driving your vehicle. Improperly secured
loads can fly off the vehicle, particularly
at high speeds, resulting in personal
injury or property damage. Follow the roof
rack cautions when carrying cargo on your
roof rack.
CAUTION!
To avoid damage to the roof rack and
vehicle, do not exceed the maximum roof
rack load capacity. Always distribute
heavy loads as evenly as possible and
secure the load appropriately.
Long loads, which extend over the wind
-
shield, should be secured to both the
front and rear of the vehicle.
Place a blanket or other protection
between the surface of the roof and the
load.
Travel at reduced speeds and turn
corners carefully when carrying large or
heavy loads on the roof rack. Wind
forces, due to natural causes or nearby
truck traffic, can add sudden upward
loads. It is recommended to not carry
large flat loads, such as wood panels or
surfboards, which may result in damage
to the cargo or your vehicle.
Load should always be secured to cross
bars first, with tie down loops used as
additional securing points if needed. Tie
loops are intended as supplementary tie
down points only. Do not use ratcheting
mechanisms with the tie loops. Check
the straps frequently to be sure that the
load remains securely attached.
CAUTION! (Continued)
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GETTING TO KNOW YOUR INSTRUMENT PANEL
66

Vehicles equipped with the Anti-Lock Brake
System (ABS) are also equipped with Electronic
Brake Force Distribution (EBD). In the event of an
EBD failure, the Brake Warning Light will turn on
along with the ABS Light. Immediate repair to the
ABS system is required.

Operation of the Brake Warning Light can be
checked by turning the ignition switch from
the OFF position to the ON/RUN position.
The light should illuminate for approximately
four seconds. The light should then turn off
unless the parking brake is applied or a brake
fault is detected. If the light does not illumi-
nate, have the light inspected by an autho -
rized dealer.
The light also will turn on when the parking
brake is applied with the ignition switch in
the ON/RUN position.
NOTE:
This light shows only that the parking brake
is applied. It does not show the degree of
brake application.
— 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. Contact 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 or 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 Electric Power Steering (EPS)
system. Refer to “Electric Power Steering” in
“Starting And Operating” in the Owner’s
Manual for further information.
— Electronic Throttle Control (ETC)
Warning Light
This warning light will illuminate to indicate
a problem with the Electronic Throttle
Control (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 (P) position. The light should turn
off. If the light remains on with the vehicle
running, your vehicle will usually be drive -
able; 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 vehicle is
running, immediate service is required and you
may experience reduced performance, 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 position 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.

WARNING!
Continued operation with reduced assist
could pose a safety risk to yourself and
others. Service should be obtained as soon
as possible.
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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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69
The “ESC OFF Indicator Light” and the
“ESC Indicator Light” come on momen-
tarily each time the ignition is placed in
the ON/RUN or ACC/ON/RUN position.
The ESC system will make buzzing or
clicking sounds when it is active. This is
normal; the sounds will stop when ESC
becomes inactive.
This light will come on when the vehicle is
in an ESC event.
— Electronic Stability Control (ESC) OFF
Warning Light — If Equipped
This warning light indicates the Electronic
Stability Control (ESC) is off.
Each time the ignition is turned to ON/RUN
or ACC/ON/RUN, the ESC system will be on,
even if it was turned off previously.
— Loose Fuel Filler Cap Warning Light —
If Equipped
This warning light will illuminate when the
fuel filler cap is loose. Properly close the
filler cap to disengage the light. If the light
does not turn off, please see an authorized
dealer.
— Low Fuel Warning Light
When the fuel level reaches approximately
2.0 gal (7.5 L), this light will turn on and a
chime will sound. The light will remain on
until fuel is added.
— Low Washer Fluid Warning Light — If
Equipped
This warning light will illuminate when the
windshield washer fluid is low.
— Engine Check/Malfunction Indicator
Warning Light (MIL)
The Engine Check/Malfunction Indicator
Light (MIL) is a part of an Onboard Diag -
nostic System called OBD II that monitors
engine and automatic transmission control
systems. This warning light will illuminate
when the ignition is in the ON/RUN position
before engine start. If the bulb does not
come on when turning the ignition switch
from OFF to ON/RUN, have the condition
checked promptly. Certain conditions, such as a loose or
missing gas cap, poor quality fuel, etc., may
illuminate the light after engine start. The
vehicle should be serviced if the light stays
on through several typical driving styles. In
most situations, the vehicle will drive
normally and will not require towing.
When the engine is running, the MIL may
flash to alert serious conditions that could
lead to immediate loss of power or severe
catalytic converter damage. The vehicle
should be serviced by an authorized dealer
as soon as possible if this occurs. WARNING!
A malfunctioning catalytic converter, as
referenced above, 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.
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105
Air Bag Warning Light
The Occupant Restraint Controller
(ORC) monitors the readiness of the
electronic parts of the air bag
system whenever the ignition
switch is in the START or ON/RUN position.
If the ignition switch is in the OFF position or
in the ACC position, the air bag system is not
on and the air bags will not inflate.
The ORC contains a backup power supply
system that may deploy the air bag system
even if the battery loses power or it becomes
disconnected prior to deployment.
The ORC turns on the Air Bag Warning Light
in the instrument panel for approximately
four to eight seconds for a self-check when
the ignition switch is first in the ON/RUN
position. After the self-check, the Air Bag
Warning Light will turn off. If the ORC
detects a malfunction in any part of the
system, it turns on the Air Bag Warning
Light, either momentarily or continuously. A
single chime will sound to alert you if the
light comes on again after initial startup.
The ORC also includes diagnostics that will
illuminate the instrument panel Air Bag
Warning Light if a malfunction is detected that
could affect the air bag system. The diagnos
-
tics also record the nature of the malfunction.
While the air bag system is designed to be
maintenance free, if any of the following
occurs, have an authorized dealer service the
air bag system immediately.

The Air Bag Warning Light does not come on
during the four to eight seconds when the igni -
tion switch is first in the ON/RUN position.

The Air Bag Warning Light remains on
after the four to eight-second interval.
The Air Bag Warning Light comes on inter -
mittently or remains on while driving.
NOTE:
If the speedometer, tachometer, or any
engine related gauges are not working, the
Occupant Restraint Controller (ORC) may
also be disabled. In this condition the air
bags may not be ready to inflate for your
protection. Have an authorized dealer service
the air bag system immediately.
Redundant Air Bag Warning Light
If a fault with the Air Bag Warning
Light is detected, which could
affect the Supplemental Restraint
System (SRS), the Redundant Air
Bag Warning Light will illuminate on the
instrument panel. The Redundant Air Bag
Warning Light will stay on until the fault is
cleared. In addition, a single chime will
sound to alert you that the Redundant Air
Bag Warning Light has come on and a fault
has been detected. If the Redundant Air Bag
Warning Light comes on intermittently or
remains on while driving have an authorized
dealer service the vehicle immediately.
WARNING!
Ignoring the Air Bag Warning Light in your
instrument panel could mean you won’t
have the air bag system to protect you in a
collision. If the light does not come on as
a bulb check when the ignition is first
turned on, stays on after you start the
vehicle, or if it comes on as you drive, have
an authorized dealer service the air bag
system immediately.
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SAFETY
116
(Continued)
NOTE:
After an accident, remember to cycle the
ignition to the STOP (OFF/LOCK) position
and remove the key from the ignition switch
to avoid draining the battery. Carefully check
the vehicle for fuel leaks in the engine
compartment and on the ground near the
engine compartment and fuel tank before
resetting the system and starting the engine.
If there are no fuel leaks or damage to the
vehicle electrical devices (e.g. headlights)
after an accident, reset the system by
following the procedure described below. If
you have any doubt, contact an authorized
dealer.
Enhanced Accident Response System Reset
Procedure
In order to reset the Enhanced Accident
Response System functions after an event,
the ignition switch must be changed from
ignition START or ON/RUN to ignition OFF.
Carefully check the vehicle for fuel leaks in
the engine compartment and on the ground
near the engine compartment and fuel tank
before resetting the system and starting the
engine.
Maintaining Your Air Bag System
WARNING!

Modifications to any part of the air bag
system could cause it to fail when you need
it. You could be injured if the air bag
system is not there to protect you. Do not
modify the components or wiring,
including adding any kind of badges or
stickers to the steering wheel hub trim
cover or the upper passenger side of the
instrument panel. Do not modify the front
bumper, vehicle body structure, or add
aftermarket side steps or running boards.

It is dangerous to try to repair any part of
the air bag system yourself. Be sure to
tell anyone who works on your vehicle
that it has an air bag system.
Do not attempt to modify any part of your
air bag system. The air bag may inflate
accidentally or may not function properly
if modifications are made. Take your
vehicle to an authorized dealer for any air
bag system service. If your seat,
including your trim cover and cushion,
needs to be serviced in any way
(including removal or loosening/
tightening of seat attachment bolts),
take the vehicle to an authorized dealer.
Only manufacturer approved seat
accessories may be used. If it is
necessary to modify the air bag system
for persons with disabilities, contact an
authorized dealer.
WARNING! (Continued)
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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)
2020_JEEP_JL_WRANGLER_UG_RHD_UK.book Page 137