2021 JEEP WRANGLER UNLIMITED stop start

138
STARTING AND OPERATING
STARTING THE ENGINE
Before starting your vehicle, adjust your seat,
adjust both inside and outside mirrors, and
fasten your seat belts.
Normal Starting — Gasoline Engine
To Turn On The Engine Using The ENGINE
START/STOP Button
1. The transmission must be in PARK (P) orNEUTRAL (N).
2. Press and hold the brake pedal while pushing the ENGINE START/STOP
button once.
3. The system takes over and attempts to start the vehicle. If the vehicle fails to
start, the starter will disengage automat -
ically after 10 seconds.
4. If you wish to stop the cranking of the engine prior to the engine starting, push
the ENGINE START/STOP button again.
NOTE:
Normal starting of either a cold or a warm
engine is obtained without pumping or
pressing the accelerator pedal.
To Turn Off The Engine Using ENGINE START/
STOP Button
1. Place the gear selector in PARK, then push and release the ENGINE START/
STOP button. 2. The ignition will return to the OFF mode.
3. If the gear selector is not in PARK (with
vehicle stopped) and the ENGINE
START/STOP button is pushed once, the
transmission will automatically select
PARK and the engine will turn off,
however the ignition will remain in the
ACC mode (NOT the OFF mode). Never
leave a vehicle out of the PARK position,
or it could roll.

4. If the gear selector is in NEUTRAL, and the vehicle speed is below 5 mph (8 km/h),
pushing the ENGINE START/STOP button
once will turn the engine off. The ignition
will remain in the ACC mode.

5. If the vehicle speed is above 5 mph (8 km/h), the ENGINE START/STOP
button must be held for two seconds (or
three short pushes in a row) to turn the
engine off. The ignition will remain in the
ACC mode (NOT the OFF mode) if the
engine is turned off when the transmis -
sion is not in PARK.
WARNING!
When exiting the vehicle, always remove
the key fob from the ignition and lock
your vehicle.
Never leave children alone in a vehicle,
or with access to an unlocked vehicle.
Allowing children to be in a vehicle unat -
tended is dangerous for a number of
reasons. A child or others could be seri -
ously or fatally injured. Children should
be warned not to touch the parking
brake, brake pedal or the gear selector.
Do not leave the key fob in or near the
vehicle, or in a location accessible to
children. A child could operate power
windows, other controls, or move the
vehicle.
Do not leave children or animals inside
parked vehicles in hot weather. Interior
heat build-up may cause serious injury or
death.
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139
NOTE:
The system will automatically time out and
the ignition will cycle to the OFF mode after
30 minutes of inactivity if the ignition is left
in the ACC or RUN (engine not running)
mode and the transmission is in PARK.
ENGINE START/STOP Button Functions — With
Driver’s Foot OFF The Brake Pedal (In PARK Or
NEUTRAL Position)
The ENGINE START/STOP button operates
similar to an ignition switch. It has three
modes: OFF, ACC, and RUN. To change the
ignition modes without starting the vehicle
and use the accessories, follow these steps:

1. Starting with the ignition in the OFF mode,

2. Push the ENGINE START/STOP button onceto place the ignition to the ACC mode (instru -
ment cluster will display “ACC”),

3. Push the ENGINE START/STOP button a second time to place the ignition to the
RUN mode (instrument cluster will
display “ON/RUN”),
4. Push the ENGINE START/STOP button a third time to return the ignition to the
OFF mode (instrument cluster will
display “OFF”).AutoPark
AutoPark is a supplemental feature to assist
in placing the vehicle in PARK should the
situations on the following pages occur. It is
a back up system and should not be relied
upon as the primary method by which the
driver shifts the vehicle into PARK.
The conditions under which AutoPark will
engage are outlined on the following pages. If the vehicle is not in PARK and the driver turns
off the engine, the vehicle may AutoPark.
AutoPark will engage when all of these
conditions are met:
Vehicle is equipped with an 8-speed trans-
mission
Driver’s door is ajar or in conditions where
driver door is removed an additional
trigger would be if the driver is off the seat
(seat pad sensor detects driver missing).
Vehicle is not in PARK
Vehicle speed is 0 mph (0 km/h)
Ignition switched from RUN to OFF
NOTE:
For Keyless Enter-N-Go equipped vehicles,
The engine will turn off and the ignition
switch will change to ACC mode. After
30 minutes the ignition switches to OFF
automatically, unless the driver turns the
ignition switch OFF.
WARNING!
Driver inattention could lead to failure to
place the vehicle in PARK. ALWAYS DO
A VISUAL CHECK that your vehicle is in
PARK by verifying that a solid (not
blinking) “P” is indicated in the instru -
ment cluster display and on the gear
selector. If the "P" indicator is blinking,
your vehicle is not in PARK. As an added
precaution, always apply the parking
brake when exiting the vehicle.
AutoPark is a supplemental feature. It is
not designed to replace the need to shift
your vehicle into PARK. It is a back up
system and should not be relied upon as
the primary method by which the driver
shifts the vehicle into PARK.
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STARTING AND OPERATING
142
Diesel Engine Idling — In Cold Weather
Avoid prolonged idling in ambient tempera-
tures below 0°F (-18°C). Long periods of
idling may be harmful to your engine
because combustion chamber temperatures
can drop so low that the fuel may not burn
completely. Incomplete combustion allows
carbon and varnish to form on piston rings
and injector nozzles. Also, the unburned fuel
can enter the crankcase, diluting the oil and
causing rapid wear to the engine.
Stopping the Engine
The following chart should be used as a
guide in determining the amount of engine
idle time required to sufficiently cool down
the turbocharger before shut down,
depending upon the type of driving and the
amount of cargo.
Before turning off your turbo diesel engine,
always allow the engine to return to normal idle
speed and run for several seconds. This
ensures proper lubrication of the turbocharger. This is particularly necessary after any period
of hard driving.
Idle the engine a few minutes before routine
shutdown. After full load operation, idle the
engine three to five minutes before shutting
it down. This idle period will allow the lubri
-
cating oil and coolant to carry excess heat
away from the combustion chamber, bear -
ings, internal components, and turbo -
charger. This is especially important for
turbocharged, charge air cooled engines.
Turbocharger "Cool Down" Chart
Driving
Conditions Load
Turbocharger
Temperature Idle Time (In Minutes)
Before Shut Down
Stop & Go EmptyCoolLess than 1
Stop & Go Medium Warm1
Highway Speeds MediumWarm2
City Traffic Max. GCWR Warm3
Highway Speeds Max. GCWR Warm4
Uphill Grade Max. GCWR Hot5
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STARTING AND OPERATING
144
(Continued)
Ignition Park Interlock
This vehicle is equipped with an Ignition
Park Interlock which requires the transmis-
sion to be in PARK before the ignition can be
turned to the OFF mode. This helps the
driver avoid inadvertently leaving the vehicle
without placing the transmission in PARK.
This system also locks the transmission in
PARK whenever the ignition is in the OFF
mode. NOTE:
The transmission is NOT locked in PARK
when the ignition is in the ACC mode (even
though the engine will be off). Ensure that
the transmission is in PARK, and the ignition
is
OFF (not in ACC mode) before exiting the
vehicle.
Brake/Transmission Shift Interlock
System
This vehicle is equipped with a Brake Trans -
mission Shift Interlock system (BTSI) that
holds the transmission gear selector in PARK
unless the brakes are applied. To shift the
transmission out of PARK, the engine must
be running and the brake pedal must be
pressed. The brake pedal must also be
pressed to shift from NEUTRAL into DRIVE
or REVERSE when the vehicle is stopped or
moving at low speeds.
It is dangerous to shift out of PARK or
NEUTRAL if the engine speed is higher
than idle speed. If your foot is not firmly
pressing the brake pedal, the vehicle
could accelerate quickly forward or in
reverse. You could lose control of the
vehicle and hit someone or something.
Only shift into gear when the engine is
idling normally and your foot is firmly
pressing the brake pedal.
Unintended movement of a vehicle could
injure those in or near the vehicle. As
with all vehicles, you should never exit a
vehicle while the engine is running.
Before exiting a vehicle, always come to
a complete stop, then apply the parking
brake, shift the transmission into PARK,
and turn the ignition OFF. When the igni -
tion is in the OFF mode, the transmis-
sion is locked in PARK, securing the
vehicle against unwanted movement.
When exiting the vehicle, always make
sure the ignition is in the OFF mode,
remove the key fob from the vehicle, and
lock the vehicle.
WARNING! (Continued)
Never leave children alone in a vehicle,
or with access to an unlocked vehicle.
Allowing children to be in a vehicle unat -
tended is dangerous for a number of
reasons. A child or others could be seri -
ously or fatally injured. Children should
be warned not to touch the parking
brake, brake pedal or the transmission
gear selector.
Do not leave the key fob in or near the
vehicle (or in a location accessible to
children), and do not leave the ignition
in the ACC or ON/RUN mode. A child
could operate power windows, other
controls, or move the vehicle.
WARNING! (Continued)
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STARTING AND OPERATING
146
The transmission will automatically down-
shift to FIRST gear when coming to a stop.
After a stop, the driver should manually
upshift (+) the transmission as the vehicle
is accelerated.
You can start out, from a stop, in FIRST or
SECOND gear (or THIRD gear, in 4L
range). Tapping (+) (at a stop) will allow
starting in SECOND gear. Starting out in
SECOND or THIRD gear can be helpful in
snowy or icy conditions.
If a requested downshift would cause the
engine to over-speed, that shift will not
occur.
The system will ignore attempts to upshift
at too low of a vehicle speed.
Holding the gear selector in the (-) posi -
tion will downshift the transmission to the
lowest gear possible at the current speed.
Transmission shifting will be more notice-
able when AutoStick is enabled.
The system may revert to automatic shift
mode if a fault or overheat condition is
detected. NOTE:
When Hill Descent Control is enabled, Auto
-
Stick is not active.
To disengage AutoStick mode, return the
gear selector to the DRIVE position. You can
shift in or out of the AutoStick position at any
time without taking your foot off the acceler -
ator pedal.
FOUR–WHEEL DRIVE
OPERATION
Four-Position Transfer Case
Four-Wheel Drive Gear Selector
The transfer case provides four mode posi -
tions:
2H (Two-Wheel Drive High Range)
4H (Four-Wheel Drive High Range)
N (Neutral)
4L (Four-Wheel Drive Low Range)
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.
WARNING!
Do not downshift for additional engine
braking on a slippery surface. The drive
wheels could lose their grip and the
vehicle could skid, causing a collision or
personal injury.
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.
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STARTING AND OPERATING
148
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.
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
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 -
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).
Five-Position Transfer Case
Four-Wheel Drive Gear Selector
The transfer case provides five mode posi -
tions:
2H (Two-Wheel Drive High Range)
4H AUTO (Four-Wheel Drive Auto High
Range)
4H PT (Four-Wheel Drive Part Time High
Range)
N (Neutral)
4L (Four-Wheel Drive Low Range)
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.

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STARTING AND OPERATING
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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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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