2018 JEEP WRANGLER UNLIMITED traction control

— Low Diesel Exhaust Emissions Addi-
tive AdBlue (UREA) Indicator Light — If
Equipped
The Low Diesel Exhaust Emissions Additive
AdBlue (UREA) indicator light illuminates
when the AdBlue (UREA) level is low.
Fill the AdBlue (UREA) tank as soon as pos-
sible with at least 1.3 gallons (5 liters) of
AdBlue (UREA).
If filling the tank is done with a remaining
range of AdBlue (UREA) in the tank equal to
zero, you may need to wait 2 minutes before
starting the vehicle.
Refer to “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.
CAUTION!
The presence of water in the fuel system
circuit may cause severe damage to the
injection system and irregular engine op-
eration. If the indicator light is illumi-
nated, 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.
Green Indicator Lights
4HAUTO— 4WD Auto Indicator Light — If
Equipped
This light alerts the driver that the vehicle is
in the four-wheel drive auto mode. The sys-
tem 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 conditions.
— Active Speed Limiter SET Indicator
Light — If Equipped With A Premium Instru-
ment Cluster
This indicator light will illuminate when the
Active Speed Limiter is on and set to a
specific speed.
— Cruise Control SET Indicator Light
— If Equipped With A Premium Instrument
Cluster
This indicator light will illuminate when the
speed control is set to the desired speed.
Refer to “Speed Control — If Equipped” in
“Starting And Operating” for further informa-
tion.
— Front Fog Indicator Light — If
Equipped
This indicator light will illuminate when the
front fog lights are on.
— Park/Headlight On Indicator Light
This indicator light will illuminate when the
park lights or headlights are turned on.
75

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 en-
sure 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.
WARNING!
• The ABS contains sophisticated elec-
tronic equipment that may be suscep-
tible to interference caused by improp-
erly installed or high output radio
transmitting equipment. This interfer-
ence 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
efficiency beyond that afforded by the
WARNING!
condition of the vehicle brakes and tires
or the traction afforded.
• The ABS cannot prevent collisions, in-
cluding 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.
ABS is designed to function with the OEM
tires. Modification may result in degraded
ABS performance.
Anti-Lock Brake Warning Light
The yellow “Anti-Lock Brake Warning Light”
will turn on when the ignition is turned to the
ON/RUN mode and may stay on for as long as
four seconds.
If the “Anti-Lock Brake Warning Light” re-
mains 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
SAFETY
82

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
turned to the ON/RUN mode, have the light
repaired as soon as possible.
Electronic Brake Control System
Your vehicle is equipped with an advanced
Electronic Brake Control system (EBC). This
system includes Electronic Brake Force Dis-
tribution (EBD), Anti-Lock Brake System
(ABS), Brake Assist System (BAS), Hill Start
Assist (HSA), Traction Control System (TCS),
Electronic Stability Control (ESC), and Elec-
tronic Roll Mitigation (ERM). These systems
work together to enhance both vehicle stabil-
ity and control in various driving conditions.Your vehicle may also be equipped with
Trailer Sway Control (TSC), Ready Alert Brak-
ing (RAB), Rain Brake Support (RBS), Dy-
namic Steering Torque (DST), and Hill De-
scent Control (HDC).
Electronic Brake Force Distribution (EBD)
This function manages the distribution of the
braking torque between the front and rear
axles by limiting braking pressure to the rear
axle. This is done to prevent overslip of the
rear wheels to avoid vehicle instability, and to
prevent the rear axle from entering ABS be-
fore the front axle.
Brake System Warning Light
The red “Brake System Warning Light” will
turn on when the ignition is turned to 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 indicates that
the brake system is not functioning properly
and that immediate service is required. If the“Brake System Warning Light” does not
come on when the ignition is turned to the
ON/RUN mode, have the light repaired as
soon as possible.
Brake Assist System (BAS)
The BAS is designed to optimize the vehicle’s
braking capability during emergency braking
maneuvers. The system detects an emer-
gency braking situation by sensing the rate
and amount of brake application and then
applies optimum pressure to the brakes. This
can help reduce braking distances. The BAS
complements the anti-lock brake system
(ABS). Applying the brakes very quickly re-
sults in the best BAS assistance. To receive
the benefit of the system, you must apply
continuous braking pressure during the stop-
ping 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
83

WARNING!
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 man-
ner, which could jeopardize the user's
safety or the safety of others.
Hill Start Assist (HSA)
The HSA system is designed to mitigate roll
back from a complete stop while on an in-
cline. 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 up-
hill direction (i.e., vehicle facing uphill is in
forward gear; vehicle backing uphill is in
REVERSE gear).
• HSA will work in REVERSE gear and all
forward gears. The system will not activate
if the transmission is in PARK or NEU-
TRAL. For vehicles equipped with a manual
transmission, if the clutch is pressed, HSA
will remain active.
WARNING!
There may be situations where the Hill
Start Assist (HSA) will not activate and
WARNING!
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 op-
eration 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 warn-
ings can result in a collision or serious
personal injury.
Disabling And Enabling HSA
This feature can be turned on or turned off.
To change the current setting, refer to “In-
strument Cluster Display” in “Getting To
Know Your Instrument Panel” for further in-
formation.
SAFETY
84

Towing With HSA
HSA will also provide assistance to mitigate
roll back while towing a trailer.
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 roll-
ing down an incline while resuming ac-
celeration, manually activate the trailer
brake or apply more vehicle brake pres-
sure 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.
• Failure to follow these warnings can re-
sult in a collision or serious personal
injury.
Traction Control System (TCS)
This system 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 re-
duce engine power to provide enhanced ac-
celeration and stability. A feature of the TCS,
Brake Limited Differential (BLD), functions
similar to a limited slip differential and con-
trols 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 en-
abled even if TCS and ESC are in a reduced
mode.
Electronic Stability Control (ESC)
This system enhances directional control and
stability of the vehicle under various driving
conditions. ESC corrects for oversteering or
understeering of the vehicle by applying the
brake of the appropriate wheel(s) to assist in
counteracting the oversteer or understeer
condition. Engine power may also be reduced
to help the vehicle maintain the desired path.ESC uses sensors in the vehicle to determine
the vehicle path intended by the driver and
compares it to the actual path of the vehicle.
When the actual path does not match the
intended path, ESC applies the brake of the
appropriate wheel to assist in counteracting
the oversteer or understeer condition.
• Oversteer — when the vehicle is turning
more than appropriate for the steering
wheel position.
• Understeer — when the vehicle is turning
less than appropriate for the steering wheel
position.
The “ESC Activation/Malfunction Indicator
Light” located in the instrument cluster will
start to flash as soon as the ESC system
becomes active. The “ESC Activation/
Malfunction Indicator Light” also flashes
when the TCS is active. If the “ESC
Activation/Malfunction Indicator Light” be-
gins to flash during acceleration, ease up on
the accelerator and apply as little throttle as
possible. Be sure to adapt your speed and
driving to the prevailing road conditions.
85

WARNING!
• Electronic Stability Control (ESC) can-
not prevent the natural laws of physics
from acting on the vehicle, nor can it
increase the traction afforded by prevail-
ing road conditions. ESC cannot prevent
accidents, including those resulting
from excessive speed in turns, driving on
very slippery surfaces, or hydroplaning.
ESC also cannot prevent accidents re-
sulting from loss of vehicle control due
to inappropriate driver input for the con-
ditions. Only a safe, attentive, and skill-
ful driver can prevent accidents. The
capabilities of an ESC equipped vehicle
must never be exploited in a reckless or
dangerous manner which could jeopar-
dize 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 ve-
hicle, and may negatively affect the per-
formance of the ESC system. Changes to
the steering system, suspension, brak-
WARNING!
ing system, tire type and size or wheel
size may adversely affect ESC perfor-
mance. Improperly inflated and un-
evenly worn tires may also degrade ESC
performance. Any vehicle modification
or poor vehicle maintenance that re-
duces the effectiveness of the ESC sys-
tem can increase the risk of loss of
vehicle control, vehicle rollover, per-
sonal injury and death.
ESC Operating Modes
NOTE:
Depending upon model and mode of opera-
tion, the ESC system may have multiple op-
erating modes.
ESC On
This is the normal operating mode for the
ESC. Whenever the vehicle is started, the
ESC system will be in this mode. This modeshould 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 Indicator Light”
will turn off.
NOTE:
For vehicles with multiple partial ESC modes
a momentary button push will toggle the ESC
mode. Multiple momentary button pushed
may be required to return to ESC On.
SAFETY
86

WARNING!
• When in “Partial Off” mode, the TCS
functionality of ESC, (except for the lim-
ited slip feature described in the TCS
section), has been disabled and the
“ESC Off Indicator Light” will be illumi-
nated. When in “Partial Off” mode, the
engine power reduction feature of TCS is
disabled, and the enhanced vehicle sta-
bility offered by the ESC system is re-
duced.
• Trailer Sway control (TSC) is disabled
when the ESC system is in the “Partial
Off” mode.
Full Off — If Equipped
This 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 illuminate, and the“ESC OFF” message will display in the in-
strument 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 so equipped.
WARNING!
• In the ESC “Full Off” mode, the engine
torque reduction and stability features
are disabled. Therefore, enhanced ve-
hicle stability offered by the ESC system
is unavailable. In an emergency evasive
maneuver, the ESC system will not en-
gage 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 phys-
ics from acting on the vehicle, nor can it
WARNING!
increase the traction afforded by prevail-
ing 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.
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
ignition is turned to the 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
87

Proper operation of four-wheel drive vehicles
depends on tires of equal size, type, and
circumference on each wheel. Any difference
will adversely affect shifting and cause dam-
age to the transfer case.
Because four-wheel drive provides improved
traction, there is a tendency to exceed safe
turning and stopping speeds. Do not go faster
than road conditions permit.
Shifting Procedures
2H To 4H Or 4H To 2H
Shifting between 2H and 4H can be made
with the vehicle stopped or in motion. The
preferred shifting speed would be 0 to
45 mph (72 km/h). With the vehicle in mo-
tion, the transfer case will engage/disengage
faster if you momentarily release the accel-
erator pedal after completing the shift. Do
not accelerate while shifting the transfer
case. Apply a constant force when shifting
the transfer case lever.NOTE:
• Do not attempt to make a shift while only
the front or rear wheels are spinning. The
front and rear driveshaft speeds must be
equal for the shift to take place. Shifting
while only the front or rear wheels are
spinning can cause damage to the transfer
case.
• Delayed shifts out of four-wheel drive may
be experienced due to uneven tire wear, low
or uneven tire pressures, excessive vehicle
loading, or cold temperatures.
• Shifting effort will increase with speed, this
is normal.
During cold weather, you may experience
increased effort in shifting until the transfer
case fluid warms up. This is normal.
4H To 4L Or 4L To 4H
With the vehicle rolling at 2 to 3 mph (3 to
5 km/h), shift the transmission into NEU-
TRAL (N). While the vehicle is coasting at
2 to 3 mph (3 to 5 km/h), shift the transfer
case lever firmly to the desired position. Donot pause with the transfer case in N (Neu-
tral). 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).
WARNING!
Failure to engage a transfer case position
completely can cause transfer case dam-
age or loss of power and vehicle control.
You could have a collision. Do not drive the
vehicle unless the transfer case is fully
engaged.
STARTING AND OPERATING
152