JEEP WRANGLER UNLIMITED 2021 Owner handbook (in English)

149
For additional information on the appropriate
use of each transfer case mode position, see
the information below:
2H
Two-Wheel Drive High Range — This range is
for normal street and highway driving on dry,
hard surfaced roads.
4H AUTO
Four-Wheel Drive Auto High Range — This
range sends power to the front wheels. The
four-wheel drive system will be automatically
engaged when the vehicle senses a loss of
traction. Additional traction for varying road
conditions.
4H PT
Four-Wheel Drive Part Time High Range —
This range maximizes torque to the front
driveshaft, forcing the front and rear wheels
to rotate at the same speed. This range
provides additional traction for loose, slip-
pery road surfaces only. NEUTRAL (N)
Neutral — This range disengages both the
front and rear driveshafts from the power
-
train. To be used for flat towing behind
another vehicle.
Refer to “Recreational Towing” in this
chapter for further information. 4L
Four-Wheel Drive Low Range — This range
provides low speed four-wheel drive. It maxi
-
mizes torque to the front driveshaft, forcing
the front and rear wheels to rotate at the
same speed. This range provides additional
traction and maximum pulling power for
loose, slippery road surfaces only. Do not
exceed 25 mph (40 km/h).
This transfer case is designed to be driven in
the 2H mode or 4H AUTO mode for normal
street and highway conditions on dry hard
surfaced roads. Driving the vehicle in 2H will
have greater fuel economy benefits as the
front axle is not engaged in 2H.
For variable driving conditions, the 4H AUTO
mode can be used. In this mode, the front
axle is engaged, but the vehicle's power is
sent to the rear wheels. Four-wheel drive will
be automatically engaged when the vehicle
senses a loss of traction. Because the front
axle is engaged, this mode will result in lower
fuel economy than the 2H mode.
WARNING!
You or others could be injured or killed if
you leave the vehicle unattended with the
transfer case in the NEUTRAL (N) position
without first fully engaging the parking
brake. The transfer case NEUTRAL (N)
position disengages both the front and rear
driveshafts from the powertrain, and will
allow the vehicle to roll, even if the
automatic transmission is in PARK. The
parking brake should always be applied
when the driver is not in the vehicle.
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150
In the event that additional traction is
required, the transfer case 4H and 4L posi-
tions can be used to lock the front and rear
driveshafts together, forcing the front and
rear wheels to rotate at the same speed. The
4H and 4L positions are intended for loose,
slippery road surfaces only and not intended
for normal driving. Driving in the 4H and 4L
positions on hard-surfaced roads will cause
increased tire wear and damage to the drive -
line components. Refer to “Shifting Proce -
dures” in this section for further information
on shifting into 4H or 4L.
The instrument cluster alerts the driver that
the vehicle is in four-wheel drive, and the
front and rear driveshafts are locked
together. The light will illuminate when the
transfer case is shifted into the 4H position.
When operating your vehicle in 4L, the
engine speed will be approximately three
times (four times for Rubicon models) that of
the 2H or 4H positions at a given road speed.
Take care not to overspeed the engine.
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
damage 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 Auto Or 4H Auto To 2H
Shifting between 2H and 4H Auto 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
motion, the transfer case will engage/disen
-
gage faster if you momentarily release the
accelerator pedal after completing the shift.
Do not accelerate while shifting the transfer
case. Apply a constant force when shifting
the transfer case lever.
2H/4H Auto To 4H Part Time Or 4H Part Time To
2H/4H Auto
Shifting between 2H/4H AUTO to 4H PART
TIME 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 motion, the transfer case will
engage/disengage faster if you momentarily
release the accelerator 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 Part Time/4H Auto To 4L Or 4L To 4H Part Time/
4H Auto
With the vehicle rolling at 2 to 3 mph (3 to
5 km/h), shift the transmission into
NEUTRAL (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 posi -
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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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152
(the “FRONT + REAR” will illuminate).
When the rear axle is locked, pushing the
bottom of switch again will lock or unlock the
front axle.
NOTE:
The indicator lights will flash until the axles
are fully locked or unlocked.
To unlock the axles, push the AXLE LOCK
OFF button.
Axle lock will disengage if the vehicle is
taken out of 4L (Low) range, or the ignition
switch is turned to the OFF position.
The axle lock disengages at speeds above
30 mph (48 km/h), and will automaticallyre-lock once vehicle speed is less than
10 mph (16 km/h).
Electronic Sway Bar Disconnect — If
Equipped
Your vehicle may be equipped with an elec -
tronic disconnecting stabilizer/sway bar. This
system allows greater front suspension travel
in off-road situations. This system is controlled by the SWAY BAR
switch located on the instrument panel (to
the right of the steering column).
SWAY BAR Switch
Push the SWAY BAR switch to activate the
system. Push the switch again to deactivate
the system. The “Sway Bar Indicator Light”
(located in the instrument cluster) will illu -
minate when the bar is disconnected. The
“Sway Bar Indicator Light” will flash during
activation transition, or when activation
conditions are not met. The stabilizer/sway
bar should remain in on-road mode during
normal driving conditions. To disconnect the stabilizer/sway bar, shift to
either 4H or 4L and push the SWAY BAR
switch to obtain the off-road position. Refer
to “Four-Wheel Drive Operation” in this
section for further information. The “Sway
Bar Indicator Light” will flash until the stabi
-
lizer/sway bar has been fully disconnected.
WARNING!
Ensure the stabilizer/sway bar is
reconnected before driving on hard
surfaced roads or at speeds above 18 mph
(29 km/h); a disconnected stabilizer/sway
bar may contribute to the loss of vehicle
control, which could result in serious
injury. Under certain circumstances, the
front stabilizer/sway bar enhances vehicle
stability and assists with vehicle control.
The system monitors vehicle speed and
will attempt to reconnect the stabilizer/
sway bar at speeds over 18 mph (29 km/
h). This is indicated by a flashing or solid
“Sway Bar Indicator Light.” Once vehicle
speed is reduced below 14 mph (22 km/
h), the system will once again attempt to
return to off-road mode.
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153
NOTE:
The stabilizer/sway bar may be torque locked
due to left and right suspension height
differences. This condition is due to driving
surface differences or vehicle loading. In
order for the stabilizer/sway bar to discon-
nect/reconnect, the right and left halves of
the bar must be aligned. This alignment may
require that the vehicle be driven onto level
ground or rocked from side to side.
To return to on-road mode, push the SWAY
BAR switch again.
STOP/START SYSTEM —
AUTOMATIC TRANSMISSION
(IF EQUIPPED)

The Stop/Start function is developed to
reduce fuel consumption. The system will
stop the engine automatically during a
vehicle stop if the required conditions are
met. Releasing the brake pedal or pressing
the accelerator pedal will automatically
re-start the engine.
Engine Stop/Start (ESS) vehicles have been
upgraded with a heavy duty starter,
enhanced battery, and other upgraded
engine parts, to handle the additional engine
starts.
NOTE:
It is recommended that the Stop/Start
System be disabled during off-road use. Secondary Battery
Your vehicle may be equipped with a
secondary battery used to power the Stop/
Start system and the 12 Volt vehicle elec
-
trical system. The secondary battery is
located behind the wheel well for the front
driver’s side wheel.
Battery Locations
WARNING!
If the stabilizer/sway bar will not return to
on-road mode, the “Sway Bar Indicator
Light” will flash in the instrument cluster
and vehicle stability may be reduced. Do
not attempt to drive the vehicle over
18 mph (29 km/h). Driving faster than
18 mph (29 km/h) with a disconnected
stabilizer/sway bar may contribute to the
loss of vehicle control, which could result
in serious injury.
1 — Primary Battery
2 — Secondary Battery
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Automatic Mode
The Stop/Start feature is enabled
after every normal customer engine
start. At that time, the system will
go into STOP/START READY and if
all other conditions are met, can go into a
STOP/START AUTOSTOP ACTIVE
“Autostop” mode.
To Activate The Autostop Mode, The Following
Must Occur:
The system must be in STOP/START
READY state. A STOP/START READY
message will be displayed in the instru -
ment cluster display within the Stop/Start
section. Refer to “Instrument Cluster” in
“Getting To Know Your Instrument Panel”
in your Owner’s Manual for further infor -
mation.
The vehicle must be completely stopped.
The shifter must be in a forward gear and
the brake pedal depressed.
The engine will shut down, the tachometer
will move to the zero position and the Stop/
Start telltale will illuminate indicating you
are in Autostop. Customer settings will be
maintained upon return to an engine running
condition. Refer to the “Stop/Start System” in the
“Starting And Operating” section located in
your Owner’s Manual for further information.
Possible Reasons The Engine Does Not
Autostop
Prior to engine shut down, the system will
check many safety and comfort conditions to
see if they are fulfilled. Detailed information
about the operation of the Stop/Start system
may be viewed in the instrument cluster
display Stop/Start Screen. In the following
situations, the engine will not stop:
Driver’s seat belt is not buckled.
Driver’s door is not closed.
Battery temperature is too warm or cold.
Battery charge is low.
The vehicle is on a steep grade.
Cabin heating or cooling is in process and
an acceptable cabin temperature has not
been achieved.
HVAC is set to full defrost mode at a high
blower speed.
HVAC set to MAX A/C.
Engine has not reached normal operating
temperature.
Engine temperature too high.
The transmission is not in a forward gear.
Hood is open.
Transfer case is in 4L or Neutral.
Brake pedal is not pressed with sufficient
pressure.
Other Factors Which Can Inhibit Autostop
Include:
Accelerator pedal input.
Vehicle speed threshold not achieved from
previous auto-stop.
Steering angle beyond threshold. (ESS
Models Only)
ACC is on and speed is set.
Vehicle is at high altitude.
System fault present.
It may be possible for the vehicle to be driven
several times without the Stop/Start system
going into a STOP/START READY state
under more extreme conditions of the items
listed above.
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155
To Start The Engine While In Autostop
Mode
While in a forward gear, the engine will start
when the brake pedal is released or the
throttle pedal is depressed. The transmission
will automatically re-engage upon engine
restart.
Conditions That Will Cause The Engine To Start
Automatically While In Autostop Mode:
The transmission selector is moved out of
DRIVE.
To maintain cabin temperature comfort.
Actual cabin temperature is significantly
different than temperature set on Auto
HVAC.
HVAC is set to full defrost mode.
HVAC system temperature or fan speed is
manually adjusted.
Battery voltage drops too low.
Low brake vacuum (e.g. after several brake
pedal applications).
Stop/Start OFF switch is pushed.
A Stop/Start system error occurs.
STOP/START AUTO STOP ACTIVE time
exceeds 5 minutes.
4WD system is put into 4L or Neutral
mode.
Steering wheel is turned beyond
threshold. (ESS Models Only)
To Manually Turn Off The Stop/Start
System
1. Push the Stop/Start OFF switch (located
on the switch bank). The light on the
switch will illuminate.
Stop/Start OFF switch
2. The “STOP/START OFF” message will appear in instrument cluster display
within the Stop/Start section. Refer to
“Instrument Cluster” in “Getting To Know Your Instrument Panel” in your
Owner’s Manual for further information.
3. At the next vehicle stop (after turning off the Stop/Start system), the engine will
not be stopped.
4. The Stop/Start system will reset itself back to an ON condition every time the
ignition is turned off and back on.To Manually Turn On The Stop/Start
System
Push the Stop/Start OFF switch (located on
the switch bank). The light on the switch will
turn off.

For complete details on the Stop/Start System
refer to the “Stop/Start System” in the
“Starting And Operating” section located in
your Owner’s Manual for further information.

System Malfunction
If there is a malfunction in the Stop/Start
system, the system will not shut down the
engine. A “SERVICE STOP/START SYSTEM”
message will appear in the instrument
cluster display. Refer to “Instrument Cluster
Display“ in “Getting to Know Your Instru -
ment Panel” for further information.
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156
If the “SERVICE STOP/START SYSTEM”
message appears in the instrument cluster
display, have the system checked by an
authorized dealer.
ACTIVE SPEED LIMITER — IF
EQUIPPED
Active Speed Limiter Button
The Active Speed Limiter button is posi -
tioned on the right side of the steering wheel.
This feature allows you to program the
maximum speed of travel for your vehicle.
NOTE:
The Active Speed Limiter can be set with the
vehicle stationary, or in motion.
Activation
To activate the feature, push the Active
Speed Limiter button, and a message will
appear along with an indicator light in the
instrument cluster display to signal that
Active Speed Limiter has been activated.

Push the SET (+) and SET (–) buttons on the
right of the steering wheel to raise and lower
the Active Speed Limiter to the desired value.
Pushing and holding down the SET (+) or SET
(–) buttons will increase/decrease the speed
value by increments of 5 mph (5 km/h).

Each time that Active Speed Limiter is acti -
vated, it will be set to the last programmed
value from the previous activation.
NOTE:
The Speed Control (if equipped) and Adap -
tive Cruise Control (if equipped) features will
be unavailable while the Active Speed
Limiter is in use.
Exceeding The Set Speed
By fully pressing the accelerator pedal, the
programmed maximum speed can be
exceeded while the device is active.
In the event that the Active Speed Limiter
set value is exceeded manually with a driver
acceleration, an audible indicator will sound,
the indicator light will rapidly flash, and a
message will appear in the instrument
cluster display.
The feature will remain disabled until the
vehicle speed drops below the set Active
Speed Limiter value, where it will reactivate
automatically.
Deactivation
To turn off Active Speed Limiter, push the
Active Speed Limiter button on the right side
of the steering wheel. A message will appear
in the instrument cluster display to confirm
that the feature has been turned off.
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157
SPEED CONTROL
When engaged, the Speed Control takes over
accelerator operations at speeds greater than
20 mph (32 km/h).The Speed Control buttons are located on the
right side of the steering wheel.
Speed Control Buttons NOTE:In order to ensure proper operation, the
Speed Control System has been designed
to shut down if multiple Speed Control
functions are operated at the same time. If
this occurs, the Speed Control System can
be reactivated by pushing the Speed
Control on/off button and resetting the
desired vehicle set speed.
Do not place the gear selector in neutral
when Speed Control is activated. Doing so
will disengage the system.
To Activate
Push the on/off button to activate the Speed
Control. The cruise indicator light in the
instrument cluster display will illuminate. To
turn the system off, push the on/off button a
second time. The cruise indicator light will
turn off. The system should be turned off
when not in use.
1 — SET (+)/Accel
2 — On/Off
3 — RES/Resume
4 — SET (-)/Decel
5 — CANC/Cancel
WARNING!
Speed Control can be dangerous where the
system cannot maintain a constant speed.
Your vehicle could go too fast for the
conditions, and you could lose control and
have an accident. Do not use Speed
Control in heavy traffic or on roads that are
winding, icy, snow-covered or slippery.
WARNING!
Leaving the Speed Control system on when
not in use is dangerous. You could
accidentally set the system or cause it to
go faster than you want. You could lose
control and have an accident. Always leave
the system off when you are not using it.
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158
To Set A Desired Speed
Turn the Speed Control on.
NOTE:
The vehicle should be traveling at a steady
speed and on level ground before pushing
the SET (+) or SET (-) button.
When the vehicle has reached the desired
speed, push the SET (+) or SET (-) button
and release. Release the accelerator and the
vehicle will operate at the selected speed.
To Resume Speed
To resume a previously set speed, push the
RES button and release. Resume can be
used at any speed above 20 mph (32 km/h).
To Deactivate
A soft tap on the brake pedal, pushing the
CANC (cancel) button, or normal brake pres-
sure while slowing the vehicle will deactivate
the Speed Control without erasing the set
speed from memory.
Pushing the on/off button or placing the igni -
tion in the OFF position, erases the set speed
from memory.
ADAPTIVE CRUISE
CONTROL (ACC) — IF
EQUIPPED
Adaptive Cruise Control Buttons
If your vehicle is equipped with Adaptive
Cruise Control, the controls operate exactly
the same as Speed Control with only a couple
of differences. With this option, you can set
a specified distance you would like to main -
tain between you and the vehicle in front of
you. If the ACC sensor detects a vehicle ahead,
ACC will apply limited braking or accelera
-
tion automatically to maintain a preset
following distance, while matching the speed
of the vehicle ahead.
If the sensor does not detect a vehicle ahead
of you, ACC will maintain a fixed set speed.
To Activate/Deactivate
Push and release the Adaptive Cruise Control
(ACC) on/off button. The ACC menu in the
instrument cluster displays “ACC Ready.”
To turn the system off, push and release the
Adaptive Cruise Control (ACC) on/off button
again. At this time, the system will turn off
and the instrument cluster displays “Adap -
tive Cruise Control (ACC) Off.”
1 — Distance Setting Increase
2 — Adaptive Cruise Control (ACC) On/Off
3 — Distance Setting Decrease
WARNING!
Leaving the Adaptive Cruise Control (ACC)
system on when not in use is dangerous.
You could accidentally set the system or
cause it to go faster than you want. You
could lose control and have a collision.
Always leave the system off when you are
not using it.
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