traction control JEEP WRANGLER UNLIMITED 2021 Owner handbook (in English)

73
Refer to “Starting The Engine” in “Starting
And Operating” for further information.
NOTE:
The “Wait To Start” telltale may not illumi-
nate if the intake manifold temperature is
warm enough.
— Low Diesel Exhaust Emissions Additive
AdBlue® Indicator Light — If Equipped
The Low Diesel Exhaust Emissions Additive
AdBlue® indicator light illuminates when
the AdBlue® (UREA) level is low.
Fill the AdBlue® tank as soon as possible
with at least 1.3 gallons (5 liters) of
AdBlue®.
If filling the tank is done with a remaining
range of AdBlue® in the tank equal to zero,
you may need to wait two minutes before
starting the vehicle.
Refer to “Adding AdBlue®” in “Starting And
Operating” for further information.
— Water In Fuel Indicator Light — If
Equipped
The “Water In Fuel Indicator Light” will illu -
minate when there is water detected in the
fuel filter. If this light remains on, DO NOT start the vehicle before you drain the water
from the fuel filter to prevent engine
damage, and please see an authorized
dealer.
Green Indicator Lights
— Adaptive Cruise Control (ACC) Set With
No Target Detected Indicator Light — If
Equipped
This light will turn on when the Adaptive
Cruise Control is set and there is no target
vehicle detected. Refer to “Adaptive Cruise
Control (ACC) — If Equipped” in “Starting
And Operating” for further information.
— Adaptive Cruise Control (ACC) Set With
Target Light — If Equipped
This will display when the ACC is set and a
target vehicle is detected. Refer to “Adaptive
Cruise Control (ACC) — If Equipped” in
“Starting And Operating” for further informa -
tion.
— 4WD Auto Indicator Light — If
Equipped
This light alerts the driver that the vehicle is
in the four-wheel drive auto mode. The
system will provide power to all four wheels
and shift the power between the front and
rear axles as needed. This will provide
maximum traction in dry and slippery condi -
tions.
— Active Speed Limiter SET Indicator
Light — If Equipped With A Premium
Instrument Cluster
This indicator light will illuminate when the
Active Speed Limiter is on and set to a
specific speed.
Refer to “Active Speed Limiter — If
Equipped” in “Starting And Operating” for
further information.
CAUTION!
The presence of water in the fuel system
circuit may cause severe damage to the
injection system and irregular engine
operation. If the indicator light is
illuminated, contact an authorized dealer
as soon as possible to bleed the system. If
the above indications come on
immediately after refuelling, water has
probably been poured into the tank: switch
the engine off immediately and contact an
authorized dealer.
2020_JEEP_JL_WRANGLER_UG_RHD_UK.book Page 73

78
(Continued)
SAFETY
SAFETY FEATURES
Anti-Lock Brake System (ABS)
The Anti-Lock Brake System (ABS) provides
increased vehicle stability and brake perfor-
mance under most braking conditions. The
system automatically prevents wheel lock,
and enhances vehicle control during braking.
The ABS performs a self-check cycle to
ensure that the ABS is working properly each
time the vehicle is started and driven. During
this self-check, you may hear a slight
clicking sound as well as some related motor
noises.
ABS is activated during braking when the
system detects one or more wheels begin to
lock. Road conditions such as ice, snow,
gravel, bumps, railroad tracks, loose debris,
or panic stops may increase the likelihood of
ABS activation(s). You also may experience the following when
ABS activates:
The ABS motor noise (it may continue to
run for a short time after the stop)
The clicking sound of solenoid valves
Brake pedal pulsations
A slight drop of the brake pedal at the end
of the stop
These are all normal characteristics of ABS.
ABS is designed to function with the Original
Equipment Manufacturer (OEM) tires. Modi-
fication may result in degraded ABS perfor -
mance.
Anti-Lock Brake Warning Light
The yellow “Anti-Lock Brake 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.
WARNING!

The ABS contains sophisticated electronic
equipment that may be susceptible to inter -
ference caused by improperly installed or
high output radio transmitting equipment.
This interference can cause possible loss of
anti-lock braking capability. Installation of
such equipment should be performed by
qualified professionals.

Pumping of the Anti-Lock Brakes will
diminish their effectiveness and may
lead to a collision. Pumping makes the
stopping distance longer. Just press
firmly on your brake pedal when you
need to slow down or stop.
The ABS cannot prevent the natural laws
of physics from acting on the vehicle, nor
can it increase braking or steering effi -
ciency beyond that afforded by the
condition of the vehicle brakes and tires
or the traction afforded.
The ABS cannot prevent collisions,
including those resulting from excessive
speed in turns, following another vehicle
too closely, or hydroplaning.
The capabilities of an ABS equipped
vehicle must never be exploited in a
reckless or dangerous manner that could
jeopardize the user’s safety or the safety
of others.
WARNING! (Continued)
2020_JEEP_JL_WRANGLER_UG_RHD_UK.book Page 78

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.
2020_JEEP_JL_WRANGLER_UG_RHD_UK.book Page 79

81
(Continued)ESC Operating Modes
NOTE:
Depending upon model and mode of opera-
tion, the ESC system may have multiple
operating modes.
ESC On
“ESC On” is the normal operating mode for
the ESC. Whenever the vehicle is started, the
ESC system will be in this mode. This mode should be used for most driving conditions.
Alternate ESC modes should only be used for
specific reasons as noted in the following
paragraphs.
Partial Off

The “Partial Off” mode is intended for times
when a more spirited driving experience is
desired. This mode may modify TCS and ESC
thresholds for activation, which allows for more
wheel spin than normally allowed. This mode
may be useful if the vehicle becomes stuck.

To enter the “Partial Off” mode, momentarily
push the “ESC OFF” switch and the “ESC
OFF Indicator Light” will illuminate. To turn
the ESC on again, momentarily push the
“ESC OFF” switch and the “ESC OFF Indi
-
cator Light” will turn off.
NOTE:
For vehicles with multiple partial ESC
modes, a momentary button push will toggle
the ESC mode. Multiple momentary button
pushes may be required to return to “ESC
On” mode.
WARNING!
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 acci -
dents, including those resulting from
excessive speed in turns, driving on very
slippery surfaces, or hydroplaning. ESC
also cannot prevent accidents resulting
from loss of vehicle control due to inap -
propriate driver input for the conditions.
Only a safe, attentive, and skillful driver
can prevent accidents. The capabilities
of an ESC equipped vehicle must never
be exploited in a reckless or dangerous
manner which could jeopardize the
user’s safety or the safety of others.Vehicle modifications, or failure to prop -
erly maintain your vehicle, may change
the handling characteristics of your
vehicle, and may negatively affect the
performance of the ESC system.
Changes to the steering system, suspen -
sion, braking system, tire type and size
or wheel size may adversely affect ESC
performance. Improperly inflated and
unevenly worn tires may also degrade
ESC performance. Any vehicle modifica-
tion or poor vehicle maintenance that
reduces the effectiveness of the ESC
system can increase the risk of loss of
vehicle control, vehicle rollover, personal
injury and death.
WARNING! (Continued)
2020_JEEP_JL_WRANGLER_UG_RHD_UK.book Page 81

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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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.).
2020_JEEP_JL_WRANGLER_UG_RHD_UK.book Page 87

151
tion. Do not pause with the transfer case in
N (Neutral). Once the shift is completed,
place the transmission into DRIVE.
NOTE:
Shifting into or out of 4L is possible with the
vehicle completely stopped; however, diffi-
culty may occur due to the mating teeth not
being properly aligned. Several attempts may
be required for clutch teeth alignment and
shift completion to occur. The preferred
method is with the vehicle rolling at 2 to
3 mph (3 to 5 km/h). Avoid attempting to
engage or disengage 4L with the vehicle
moving faster than 2 to 3 mph (3 to 5 km/h).Trac-Lok Rear Axle — If Equipped
The Trac-Lok rear axle provides a constant
driving force to both rear wheels and reduces
wheel spin caused by the loss of traction at
one driving wheel. If traction differs between
the two rear wheels, the differential automat -
ically proportions the usable torque by
providing more torque to the wheel that has
traction.
Trac-Lok is especially helpful during slippery
driving conditions. With both rear wheels on
a slippery surface, a slight application of the
accelerator will supply maximum traction.
Axle Lock (Tru-Lok) — Rubicon Models

The AXLE LOCK switch is located on the instru -
ment panel (to the right of the steering column).

Axle Lock Switch Panel
This feature will only activate when the
following conditions are met:
Ignition in RUN position, vehicle in 4L
(Low) range.

Vehicle speed should be 10 mph (16 km/h)
or less.

Both right and left wheels on axle are at
the same speed.
To activate the system, push the AXLE LOCK
switch down to lock the rear axle only (the
“REAR ONLY” will illuminate), push the
switch up to lock the front axle and rear axle
WARNING!
Failure to engage a transfer case position
completely can cause transfer case
damage or loss of power and vehicle
control. You could have a collision. Do not
drive the vehicle unless the transfer case
is fully engaged.
WARNING!
On vehicles equipped with a limited-slip
differential, never run the engine with one
rear wheel off the ground. The vehicle may
drive through the rear wheel remaining on
the ground and cause you to lose control of
your vehicle.
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237
Tire Types
All Season Tires — If Equipped
All Season tires provide traction for all
seasons (Spring, Summer, Autumn, and
Winter). Traction levels may vary between
different all season tires. All season tires can
be identified by the M+S, M&S, M/S or MS
designation on the tire sidewall. Use all
season tires only in sets of four; failure to do
so may adversely affect the safety and
handling of your vehicle.

Summer Or Three Season Tires — If Equipped

Summer tires provide traction in both wet
and dry conditions, and are not intended to
be driven in snow or on ice. If your vehicle is
equipped with Summer tires, be aware these
tires are not designed for Winter or cold
driving conditions. Install Winter tires on
your vehicle when ambient temperatures are
less than 40°F (5°C) or if roads are covered
with ice or snow. For more information,
contact an authorized dealer.

Summer tires do not contain the all season desig-
nation or mountain/snowflake symbol on the tire
sidewall. Use Summer tires only in sets of four;
failure to do so may adversely affect the safety
and handling of your vehicle.

Snow Tires
Some areas of the country require the use of
snow tires during the Winter. Snow tires can
be identified by a “mountain/snowflake”
symbol on the tire sidewall.
If you need snow tires, select tires
equivalent in size and type to the
original equipment tires. Use snow
tires only in sets of four; failure to
do so may adversely affect the safety and
handling of your vehicle.
Snow tires generally have lower speed ratings
than what was originally equipped with your
vehicle and should not be operated at
sustained speeds over 75 mph (120 km/h).
For speeds above 75 mph (120 km/h) refer
to original equipment or an authorized tire
dealer for recommended safe operating
speeds, loading and cold tire inflation pres -
sures. While studded tires improve performance on
ice, skid and traction capability on wet or dry
surfaces may be poorer than that of
non-studded tires. Some states prohibit
studded tires; therefore, local laws should be
checked before using these tire types.
Spare Tires — If Equipped
NOTE:
For vehicles equipped with Tire Service Kit
instead of a spare tire, please refer to “Tire
Service Kit” in “In Case Of Emergency” in
the Owner’s Manual for further information.
Refer to the “Towing Requirements - Tires”
in “Starting And Operating” in the Owner’s
Manual for restrictions when towing with a
spare tire designated for temporary emer
-
gency use.
WARNING!
Do not use Summer tires in snow/ice
conditions. You could lose vehicle control,
resulting in severe injury or death. Driving
too fast for conditions also creates the
possibility of loss of vehicle control.
CAUTION!
Because of the reduced ground clearance,
do not take your vehicle through an
automatic car wash with a compact or
limited use temporary spare installed.
Damage to the vehicle may result.
2020_JEEP_JL_WRANGLER_UG_RHD_UK.book Page 237

SERVICING AND MAINTENANCE
240
(Continued)
Dark Vapor Chrome, Black Satin Chrome, or
Low Gloss Clear Coat WheelsTire Chains And Traction Devices
Use of traction devices require sufficient
tire-to-body clearance. Follow these recom-
mendations to guard against damage.
the tire, as recommended by the traction
device manufacturer.
Install on rear tires only. 

All OE equipped tire and wheel sizes are

chainable with an Autosock traction
device. See Autosock.com for the recom -
mended part or model number for your OE
equipped tire size.
permitted with the use of 245/75R17
tires on size 17 x 7.5 ET44.45 wheels.
CAUTION!
If your vehicle is equipped with these
specialty wheels, DO NOT USE wheel
cleaners, abrasives, or polishing
compounds. They will permanently
damage this finish and such damage is not
covered by the New Vehicle Limited
Warranty. HAND WASH ONLY USING
MILD SOAP AND WATER WITH A SOFT
CLOTH. Used on a regular basis; this is all
that is required to maintain this finish.
WARNING!
Using tires of different size and type
(M+S, Snow) between front and rear axles
can cause unpredictable handling. You
could lose control and have a collision.
CAUTION!
To avoid damage to your vehicle or tires,
observe the following precautions:
Because of restricted traction device
clearance between tires and other
suspension components, it is important
that only traction devices in good condi -
tion are used. Broken devices can cause
serious damage. Stop the vehicle imme-
diately if noise occurs that could indi -
cate device breakage. Remove the
damaged parts of the device before
further use.
Install device as tightly as possible and
then retighten after driving about ½ mile
(0.8 km). Autosock traction devices do
not require retightening.
Do not exceed 30 mph (48 km/h).
Drive cautiously and avoid severe turns
and large bumps, especially with a
loaded vehicle.
Do not drive for a prolonged period on
dry pavement.
2020_JEEP_JL_WRANGLER_UG_RHD_UK.book Page 240 
The use of S-class snow chains is 
Traction device must be of proper size for

322
INDEX
I
Ignition ............................................... 12Switch ............................................ 12
Installation.......................................... 51
Installing ............................................ 53
Instrument Cluster ............................... 61 Descriptions .................................... 74
Display ............................................ 60
Menu Items ..................................... 61
Instrument Panel Lens Cleaning .......... 246
Integrated Power Module (Fuses)......... 184
Interior Appearance Care .................... 245
Intermittent Wipers (Delay Wipers) ........ 35
Introduction .......................................... 1
Inverter Power.............................................. 57
J
Jack Location .................................... 193
Jack Operation .......................... 195 , 232
Jacking Instructions ........................... 195
Jump Starting ................................... 201 K
Key Fob
Arm The System .............................. 15
Disarm The System .......................... 15
Keyless Enter-N-Go.............................. 18 Passive Entry ................................... 18
Keys................................................... 11 Replacement ................................... 12
L
Lap/Shoulder Belts ............................ 100
Latches ............................................ 137 Hood .............................................. 55
Leaks, Fluid ...................................... 137
Leveling Headlights....................................... 34
Life Of Tires...................................... 235
Light Bulbs ................................137 , 179
Lights............................................... 137 Air Bag ............................ 65 , 105 , 136
Automatic Headlights ....................... 33
Brake Assist Warning........................ 82
Brake Warning ................................. 65
Bulb Replacement ..................179 , 181
Center Mounted Stop ..................... 183 Cruise ........................................74 , 76 Daytime Running ..............................32
Dimmer Switch, Headlight.................32
Electronic Stability Program (ESP)
Indicator ......................................67
Engine Temperature Warning .............67 Exterior.................................... 32 , 137
Fog ......................................... 72 , 182
Hazard Warning Flasher ..................179
Headlight Leveling ............................34
Headlights .....................................181
High Beam.......................................32
High Beam/Low Beam Select .............32 Hill Descent Control Indicator ............83Lights On Reminder ..........................34
Malfunction Indicator (Check Engine) .............................69
Park ................................................74
Passing............................................33 Rear Servicing ................................182
Rear Tail Lamps .............................182
Seat Belt Reminder .............. 67 , 74 , 75
Security Alarm .................................68
Service .................................. 179 , 181
Side Marker ...................................182
Tire Pressure Monitoring (TPMS) ........92
Traction Control................................82
Turn Signal ....................................137
Turn Signals..................... 74 , 181 , 182
Warning Instrument Cluster Descriptions ........................... 67 , 74
2020_JEEP_JL_WRANGLER_UG_RHD_UK.book Page 322