2021 JEEP WRANGLER UNLIMITED trailer

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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GETTING TO KNOW YOUR INSTRUMENT PANEL
68
— Swing Gate Open Warning Light
This warning light will illuminate when the
swing gate is open.
NOTE:
If the vehicle is moving, there will also be a
single chime.
— Transmission Temperature Warning
Light — If Equipped
This warning light will illuminate to warn of
a high transmission fluid temperature. This
may occur with strenuous usage such as
trailer towing. If this light turns on, stop the
vehicle and shift the transmission into Park
and allow the vehicle to sit idle (propulsion
system active), until the light turns off. Once
the light turns off, you may continue to drive
normally.
— Vehicle Security Warning Light — If
Equipped
This light will flash at a fast rate for approxi -
mately 15 seconds when the vehicle security
alarm is arming, and then will flash slowly
until the vehicle is disarmed.
Yellow Warning Lights
— Anti-Lock Brake (ABS) Warning Light
This warning light monitors the Anti-Lock
Brake System (ABS). The light will turn on
when the ignition is placed in the ON/RUN or
ACC/ON/RUN position and may stay on for as
long as four seconds.
If the ABS light remains on or turns on while
driving, then the Anti-Lock portion of the
brake system is not functioning and service
is required as soon as possible. However, the conventional brake system will continue to
operate normally, assuming the Brake
Warning Light is not also on.
If the ABS light does not turn on when the
ignition is placed in the ON/RUN or ACC/ON/
RUN position, have the brake system
inspected by an authorized dealer.
— Electronic Stability Control (ESC)
Active Warning Light — If Equipped
This warning light will indicate when the
Electronic Stability Control system is Active.
The “ESC Indicator Light” in the instrument
cluster will come on when the ignition is
placed in the ON/RUN or ACC/ON/RUN posi -
tion, and when ESC is activated. It should go
out with the engine running. If the “ESC
Indicator Light” comes on continuously with
the engine running, a malfunction has been
detected in the ESC system. If this warning
light remains on after several ignition cycles,
and the vehicle has been driven several miles
(kilometers) at speeds greater than 30 mph
(48 km/h), see an authorized dealer as soon
as possible to have the problem diagnosed
and corrected.
WARNING!
If you continue operating the vehicle when
the Transmission Temperature Warning
Light is illuminated you could cause the
fluid to boil over, come in contact with hot
engine or exhaust components and cause a
fire.
CAUTION!
Continuous driving with the Transmission
Temperature Warning Light illuminated
will eventually cause severe transmission
damage or transmission failure.
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79
If the “Anti-Lock Brake Warning Light”
remains on or comes on while driving, it indi-
cates that the anti-lock portion of the brake
system is not functioning and that service is
required. However, the conventional brake
system will continue to operate normally if
the “Anti-Lock Brake Warning Light” is on.
If the “Anti-Lock Brake Warning Light” is on,
the brake system should be serviced as soon
as possible to restore the benefits of
anti-lock brakes. If the “Anti-Lock Brake
Warning Light” does not come on when the
ignition is placed in the ON/RUN mode, have
the light repaired as soon as possible.
Electronic Brake Control (EBC) System

Your vehicle is equipped with an advanced
Electronic Brake Control (EBC) system. This
system includes Electronic Brake Force Distri -
bution (EBD), Anti-Lock Brake System (ABS),
Brake Assist System (BAS), Hill Start Assist
(HSA), Traction Control System (TCS), Elec-
tronic Stability Control (ESC), and Electronic
Roll Mitigation (ERM). These systems work
together to enhance both vehicle stability and
control in various driving conditions.
Your vehicle may also be equipped with
Trailer Sway Control (TSC), Ready Alert
Braking (RAB), Rain Brake Support (RBS),
and Hill Descent Control (HDC).
Brake System Warning Light
The red “Brake System Warning Light” will
turn on when the ignition is placed in the
ON/RUN mode and may stay on for as long
as four seconds.
If the “Brake System Warning Light”
remains on or comes on while driving, it indi
-
cates that the brake system is not func -
tioning properly and that immediate service
is required. If the “Brake System Warning
Light” does not come on when the ignition is
placed in the ON/RUN mode, have the light
repaired as soon as possible.
Brake Assist System (BAS)
The Brake Assist System (BAS) is designed
to optimize the vehicle’s braking capability
during emergency braking maneuvers. The
system detects an emergency braking situa -
tion by sensing the rate and amount of brake
application and then applies optimum pres -
sure to the brakes. This can help reduce
braking distances. The BAS complements
the Anti-Lock Brake System (ABS). Applying the brakes very quickly results in the best
BAS assistance. To receive the benefit of the
system, you must apply continuous braking
pressure during the stopping sequence, (do
not “pump” the brakes). Do not reduce brake
pedal pressure unless braking is no longer
desired. Once the brake pedal is released,
the BAS is deactivated.
WARNING!
The Brake Assist System (BAS) cannot
prevent the natural laws of physics from
acting on the vehicle, nor can it increase
the traction afforded by prevailing road
conditions. BAS cannot prevent collisions,
including those resulting from excessive
speed in turns, driving on very slippery
surfaces, or hydroplaning. The capabilities
of a BAS-equipped vehicle must never be
exploited in a reckless or dangerous
manner, which could jeopardize the user's
safety or the safety of others.
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SAFETY
82
(Continued)
Full Off — If Equipped

The “Full Off” mode is intended for off-highway or
off-road use only and should not be used on any
public roadways. In this mode, TCS and ESC
features are turned off. To enter the “Full Off”
mode, push and hold the “ESC OFF” switch for
five seconds while the vehicle is stopped with the
engine running. After five seconds, a chime will
sound, the “ESC OFF Indicator Light” will illumi-
nate, and the “ESC OFF” message will display in
the instrument cluster. To turn ESC On again,
momentarily push the “ESC OFF” switch.
NOTE:
System may switch from ESC “Full Off” to
“Partial Off” mode when vehicle exceeds a
predetermined speed. When the vehicle
speed slows below the predetermined speed
the system will return to ESC “Full Off”.
ESC modes may also be affected by drive
modes (if equipped).
ESC Activation/Malfunction Indicator Light
And ESC OFF Indicator Light

The “ESC Activation/Malfunction
Indicator Light” in the instrument
cluster will come on when the igni
-
tion is turned to the “ESC On” mode.
It should go out with the engine running. If the
“ESC Activation/Malfunction Indicator Light”
comes on continuously with the engine
running, a malfunction has been detected in
the ESC system. If this light remains on after
several ignition cycles, and the vehicle has
been driven several miles (km) at speeds
greater than 30 mph (48 km/h), see an autho -
rized dealer as soon as possible to have the
problem diagnosed and corrected.

WARNING!

When in “Partial Off” mode, the TCS func -
tionality of ESC, (except for the limited slip
feature described in the TCS section), has
been disabled and the “ESC Off Indicator
Light” will be illuminated. When in
“Partial Off” mode, the engine power
reduction feature of TCS is disabled, and
the enhanced vehicle stability offered by
the ESC system is reduced.

Trailer Sway control (TSC) is disabled
when the ESC system is in the “Partial
Off” mode.
WARNING!
In the ESC “Full Off” mode, the engine
torque reduction and stability features
are disabled. Therefore, enhanced
vehicle stability offered by the ESC
system is unavailable. In an emergency
evasive maneuver, the ESC system will
not engage to assist in maintaining
stability. ESC “Full Off” mode is
intended for off-highway or off-road use
only.
The Electronic Stability Control (ESC)
cannot prevent the natural laws of
physics from acting on the vehicle, nor
can it increase the traction afforded by
prevailing road conditions. ESC cannot
prevent all accidents, including those
resulting from excessive speed in turns,
driving on very slippery surfaces, or
hydroplaning. ESC also cannot prevent
collisions.
WARNING! (Continued)
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85
The cluster icon and switch indicator light
will flash when HDC deactivates due to
overheated brakes. The flashing will stop
and HDC will activate again once the
brakes have cooled sufficiently.
Hill Start Assist (HSA)

The Hill Start Assist (HSA) system is designed to
mitigate roll back from a complete stop while on
an incline. If the driver releases the brake while
stopped on an incline, HSA will continue to hold
the brake pressure for a short period. If the driver
does not apply the throttle before this time
expires, the system will release brake pressure
and the vehicle will roll down the hill as normal.
The following conditions must be met in
order for HSA to activate:
The feature must be enabled
The vehicle must be stopped
Park brake must be off
Driver door must be closed. (If the doors
are attached, then the door must be
closed. If the doors are detached then the
driver's seatbelt must be buckled)
The vehicle must be on a sufficient grade
The gear selection must match vehicle
uphill direction (i.e., vehicle facing uphill
is in forward gear; vehicle backing uphill is
in REVERSE (R) gear)
HSA will work in REVERSE gear and all
forward gears. The system will not activate
if the transmission is in PARK (P) or
NEUTRAL (N). For vehicles equipped with
a manual transmission, if the clutch is
pressed, HSA will remain active.
Disabling And Enabling HSA
This feature can be turned on or turned off.
To change the current setting, refer to
“Instrument Cluster Display” in “Getting To
Know Your Instrument Panel” for further
information.
WARNING!
HDC is only intended to assist the driver in
controlling vehicle speed when descending
hills. The driver must remain attentive to
the driving conditions and is responsible
for maintaining a safe vehicle speed.
WARNING!
There may be situations where the Hill
Start Assist (HSA) will not activate and
slight rolling may occur, such as on minor
hills or with a loaded vehicle, or while
pulling a trailer. HSA is not a substitute for
active driving involvement. It is always the
driver’s responsibility to be attentive to
distance to other vehicles, people, and
objects, and most importantly brake
operation to ensure safe operation of the
vehicle under all road conditions. Your
complete attention is always required
while driving to maintain safe control of
your vehicle. Failure to follow these
warnings can result in a collision or serious
personal injury.
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SAFETY
86
Towing With HSA
HSA will also provide assistance to mitigate
roll back while towing a trailer.
Ready Alert Braking (RAB)
Ready Alert Braking (RAB) may reduce the
time required to reach full braking during
emergency braking situations. It anticipates
when an emergency braking situation may
occur by monitoring how fast the throttle is
released by the driver. The Electronic Brake
Control (EBC) system will prepare the brake
system for a panic stop.
Rain Brake Support (RBS)
Rain Brake Support (RBS) may improve
braking performance in wet conditions. It
will periodically apply a small amount of
brake pressure to remove any water buildup
on the front brake rotors. It functions when
the windshield wipers are in LO or HI speed.
When RBS is active, there is no notification
to the driver and no driver interaction is
required.
Trailer Sway Control (TSC)
Trailer Sway Control (TSC) uses sensors in
the vehicle to recognize an excessively
swaying trailer and will take the appropriate
actions to attempt to stop the sway. TSC will
become active automatically once an exces-
sively swaying trailer is recognized.

NOTE:
TSC cannot stop all trailers from swaying.
Always use caution when towing a trailer and
follow the trailer tongue weight recommenda-
tions. Refer to “Trailer Towing” in “Starting
And Operating” for further information.

When TSC is functioning, the “ESC Activa -
tion/Malfunction Indicator Light” will flash,
the engine power may be reduced and you
may feel the brakes being applied to indi -
vidual wheels to attempt to stop the trailer
from swaying. TSC is disabled when the ESC
system is in the “Partial Off” or “Full Off”
modes.
WARNING!
If you use a trailer brake controller with
your trailer, the trailer brakes may be
activated and deactivated with the brake
switch. If so, there may not be enough
brake pressure to hold both the vehicle
and the trailer on a hill when the brake
pedal is released. In order to avoid
rolling down an incline while resuming
acceleration, manually activate the
trailer brake or apply more vehicle brake
pressure prior to releasing the brake
pedal.
HSA is not a parking brake. Always apply
the parking brake fully when exiting your
vehicle. Also, be certain to place the
transmission in PARK (P).
Failure to follow these warnings can
result in a collision or serious personal
injury. WARNING!
If TSC activates while driving, slow the
vehicle down, stop at the nearest safe
location, and adjust the trailer load to
eliminate trailer sway.
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87
Traction Control System (TCS)

The Traction Control System (TCS) monitors the
amount of wheel spin of each of the driven
wheels. If wheel spin is detected, the TCS may
apply brake pressure to the spinning wheel(s) and/
or reduce engine power to provide enhanced
acceleration and stability. A feature of the TCS,
Brake Limited Differential (BLD), functions
similar to a limited slip differential and controls
the wheel spin across a driven axle. If one wheel
on a driven axle is spinning faster than the other,
the system will apply the brake of the spinning
wheel. This will allow more engine torque to be
applied to the wheel that is not spinning. BLD
may remain enabled even if TCS and Electronic
Stability Control (ESC) are in a reduced mode.

AUXILIARY DRIVING
SYSTEMS
Blind Spot Monitoring (BSM) — If
Equipped
The Blind Spot Monitoring (BSM) system
uses two radar-based sensors, located inside
the taillights, to detect highway licensable
vehicles (automobiles, trucks, motorcycles,
etc.) that enter the blind spot zones from the
rear/front/side of the vehicle.Rear Detection Zones

When the vehicle is started, the BSM warning
light will momentarily illuminate in both outside
rear view mirrors to let the driver know that the
system is operational. The BSM system sensors
operate when the vehicle is in any forward gear or
REVERSE (R) and enters standby mode when the
vehicle is in PARK (P).
The BSM detection zone covers approximately
one lane width on both sides of the vehicle, 12 ft
(3.8 m). The zone length starts at the outside rear
view mirror and extends approximately 10 ft
(3 m) beyond the rear bumper of the vehicle. The
BSM system monitors the detection zones on both
sides of the vehicle when the vehicle speed
reaches approximately 6 mph (10 km/h) or higher and will alert the driver of vehicles in these areas.
NOTE:
The BSM system DOES NOT alert the
driver about rapidly approaching vehicles
that are outside the detection zones.
The BSM system detection zone DOES
NOT change if your vehicle is towing a
trailer. Therefore, visually verify the adja-
cent lane is clear for both your vehicle and
trailer before making a lane change. If the
trailer or other object (i.e., bicycle, sports
equipment) extends beyond the side of
your vehicle, this may result in the BSM
warning light remaining illuminated the
entire time the vehicle is in a forward gear.
The Blind Spot Monitoring (BSM) system
may experience drop outs (blinking on and
off) of the side mirror Warning Indicator
lamps when a motorcycle or any small
object remains at the side of the vehicle
for extended periods of time (more than a
couple of seconds).
The area on taillights, where the radar
sensors are located, must remain free of
snow, ice, and dirt/road contamination so
that the BSM system can function properly.
Do not block the taillights where the radar
sensors are located with foreign objects
(bumper stickers, bicycle racks, etc.).
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145
Eight–Speed Automatic Transmission
Your vehicle is equipped with a fuel efficient
8 speed transmission. The gear selector is
located in the center console.Transmission Gear Selector
The transmission gear selector provides
PARK, REVERSE, NEUTRAL, DRIVE and
MANUAL (AutoStick) shift positions. Manual
shifts can be made using the AutoStick shift
control. Toggling the gear selector forward (-)
or rearward (+) while in the MANUAL (Auto -
Stick) position (beside the DRIVE position)
will manually select the transmission gear,
and will display the current gear in the
instrument cluster. Refer to "AutoStick" in
this section for further information. NOTE:
If the gear selector cannot be moved to the
PARK, REVERSE, or NEUTRAL position
(when pushed forward), it is probably in the
AutoStick (+/-) position (beside the DRIVE
position). In AutoStick mode, the transmis
-
sion gear (1, 2, 3, etc.) is displayed in the
instrument cluster. Move the gear selector to
the right (into the DRIVE [D] position) for
access to PARK, REVERSE, and NEUTRAL.
AutoStick
AutoStick is a driver-interactive transmission
feature providing manual shift control, giving
you more control of the vehicle. AutoStick
allows you to maximize engine braking, elim -
inate undesirable upshifts and downshifts,
and improve overall vehicle performance.
This system can also provide you with more
control during passing, city driving, cold slip -
pery conditions, mountain driving, trailer
towing, and many other situations. Operation

To activate AutoStick mode, move the gear
selector into the MANUAL (M) position (beside
the DRIVE position). The current transmission
gear will be displayed in the instrument cluster.
In AutoStick mode, you can use the gear
selector (in the MANUAL position) to manually
shift the transmission. Tapping the gear
selector forward (-) while in the MANUAL (M)
position will downshift the transmission to the
next lower gear. Tapping the selector rearward
(+) will command an upshift.

In AutoStick mode, the transmission will
shift up or down when (+/-) is manually
selected by the driver, unless an engine
lugging or overspeed condition would result.
It will remain in the selected gear until
another upshift or downshift is chosen,
except as described below.
The transmission will automatically down
-
shift as the vehicle slows (to prevent
engine lugging) and will display the
current gear.
2020_JEEP_JL_WRANGLER_UG_RHD_UK.book Page 145