2018 JEEP WRANGLER UNLIMITED light

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
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(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.
The “ESC Activation/Malfunction Indicator
Light” (located in the instrument cluster)
starts to flash as soon as the tires lose trac-
tion and the ESC system becomes active. The
“ESC Activation/Malfunction Indicator
Light” also flashes when TCS is active. If the
“ESC Activation/Malfunction Indicator
Light” begins 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 con-
ditions.
NOTE:
• The “ESC Activation/Malfunction Indicator
Light” and the “ESC OFF Indicator Light”
come on momentarily each time the igni-
tion is turned ON.
• Each time the ignition is turned ON, the
ESC system will be on even if it was turned
off previously.• The ESC system will make buzzing or click-
ing sounds when it is active. This is normal;
the sounds will stop when ESC becomes
inactive following the maneuver that
caused the ESC activation.
The “ESC OFF Indicator Light” indi-
cates the customer has elected to
have the Electronic Stability Control
(ESC) in a reduced mode.
Electronic Roll Mitigation (ERM)
This system anticipates the potential for
wheel lift by monitoring the driver’s steering
wheel input and the speed of the vehicle.
When ERM determines that the rate of
change of the steering wheel angle and vehi-
cle’s speed are sufficient to potentially cause
wheel lift, it then applies the appropriate
brake and may also reduce engine power to
lessen the chance that wheel lift will occur.
ERM can only reduce the chance of wheel lift
occurring during severe or evasive driving
maneuvers; it cannot prevent wheel lift due
to other factors, such as road conditions,
leaving the roadway, or striking objects or
other vehicles.NOTE:
ERM is disabled anytime the ESC is in “Full
Off” mode (if equipped). Refer to “Electronic
Stability Control (ESC)” in this section for a
complete explanation of the available ESC
modes.
WARNING!
Many factors, such as vehicle loading,
road conditions and driving conditions,
influence the chance that wheel lift or
rollover may occur. ERM cannot prevent
all wheel lift or roll overs, especially those
that involve leaving the roadway or striking
objects or other vehicles. The capabilities
of an ERM-equipped vehicle must never
be exploited in a reckless or dangerous
manner which could jeopardize the user's
safety or the safety of others.
SAFETY
88

Trailer Sway Control (TSC)
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 excessively swaying trailer is recog-
nized.
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
Activation/Malfunction Indicator Light” will
flash, the engine power may be reduced and
you may feel the brakes being applied to
individual 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 TSC activates while driving, slow the
vehicle down, stop at the nearest safe
location, and adjust the trailer load to
eliminate trailer sway.
Ready Alert Braking (RAB)
Ready Alert Braking may reduce the time
required to reach full braking during emer-
gency braking situations. It anticipates when
an emergency braking situation may occur by
monitoring how fast the throttle is released by
the driver. The EBC will prepare the brake
system for a panic stop.
Rain Brake Support (RBS)
Rain Brake Support may improve braking
performance in wet conditions. It will periodi-
cally apply a small amount of brake pressure
to remove any water buildup on the front
brake rotors. It functions when the wind-
shield wipers are in LO or HI speed. When
Rain Brake Support is active, there is no
notification to the driver and no driver inter-
action is required.
Hill Descent Control (HDC) — If Equipped
HDC is intended for low speed off road driving
while in 4WD Low Range. HDC maintains
vehicle speed while descending hills during
various driving situations. HDC controls ve-
hicle speed by actively controlling the brakes.
HDC has three states:
1. Off (feature is not enabled and will not
activate).
2. Enabled (feature is enabled and ready but
activation conditions are not met, or driver
is actively overriding with brake or throttle
application).
3. Active (feature is enabled and actively
controlling vehicle speed).
Enabling HDC
HDC is enabled by pushing the HDC switch,
but the following conditions must also be met
to enable HDC:
• Driveline is in 4WD Low Range
• Vehicle speed is below 5 mph (8 km/h).
• Parking brake is released.
89

Feedback To The Driver
The instrument cluster has an HDC icon and
the HDC switch has an indicator light, which
offers feedback to the driver about the state
HDC is in.
• The cluster icon and switch indicator light
will illuminate and remain on solid when
HDC is enabled or activated. This is the
normal operating condition for HDC.
• The cluster icon and switch indicator light
will flash for several seconds then extin-
guish when the driver pushes the HDC
switch but enable conditions are not met.
• The cluster icon and switch indicator light
will flash for several seconds then extin-
guish when HDC disables due to excess
speed.
• 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.WARNING!
HDC is only intended to assist the driver in
controlling vehicle speed when descend-
ing hills. The driver must remain attentive
to the driving conditions and is responsible
for maintaining a safe vehicle speed.
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.When the vehicle is started, the BSM warning
light will momentarily illuminate in both out-
side 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 and enters
stand-by mode when the vehicle is in PARK.
The BSM detection zone covers approxi-
mately 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
Rear Detection Zones
91