2021 JEEP WRANGLER UNLIMITED brake light

137
(Continued)
Periodic Safety Checks You Should Make
Outside The Vehicle
Tires

Examine tires for excessive tread wear and uneven
wear patterns. Check for stones, nails, glass, or
other objects lodged in the tread or sidewall.
Inspect the tread for cuts and cracks. Inspect side-
walls for cuts, cracks, and bulges. Check the wheel
nuts for tightness. Check the tires (including spare)
for proper cold inflation pressure.

Lights

Have someone observe the operation of brake
lights and exterior lights while you work the
controls. Check turn signal and high beam indi -
cator lights on the instrument panel.

Door Latches
Check for proper closing, latching, and
locking.
Fluid Leaks
Check area under vehicle after overnight
parking for fuel, coolant, oil, or other fluid
leaks. Also, if gasoline fumes are detected or
if fuel, or brake fluid leaks are suspected, the
cause should be located and corrected
immediately.
ALWAYS REMOVE THE EXISTING
FLOOR MAT FROM THE VEHICLE
before installing any other floor mat.
NEVER install or stack an additional
floor mat on top of an existing floor mat.
ONLY install floor mats designed to fit
your vehicle. NEVER install a floor mat
that cannot be properly attached and
secured to your vehicle. If a floor mat
needs to be replaced, only use a FCA
approved floor mat for the specific make,
model, and year of your vehicle.
ONLY use the driver’s side floor mat on
the driver’s side floor area. To check for
interference, with the vehicle properly
parked with the engine off, fully depress
the accelerator, the brake, and the
clutch pedal (if present) to check for
interference. If your floor mat interferes
with the operation of any pedal, or is not
secure to the floor, remove the floor mat
from the vehicle and place the floor mat
in your trunk.
ONLY use the passenger’s side floor mat
on the passenger’s side floor area.
WARNING! (Continued)
ALWAYS make sure objects cannot fall
or slide into the driver’s side floor area
when the vehicle is moving. Objects can
become trapped under accelerator,
brake, or clutch pedals and could cause
a loss of vehicle control.
NEVER place any objects under the floor
mat (e.g., towels, keys, etc.). These
objects could change the position of the
floor mat and may cause interference
with the accelerator, brake, or clutch
pedals.
If the vehicle carpet has been removed
and re-installed, always properly attach
carpet to the floor and check the floor
mat fasteners are secure to the vehicle
carpet. Fully depress each pedal to
check for interference with the acceler -
ator, brake, or clutch pedals then
re-install the floor mats.
It is recommended to only use mild soap
and water to clean your floor mats. After
cleaning, always check your floor mat
has been properly installed and is
secured to your vehicle using the floor
mat fasteners by lightly pulling mat.
WARNING! (Continued)
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147
4H
Four-Wheel Drive 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 addi-
tional traction for loose, slippery 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).
The transfer case is intended to be driven in
the 2H position for normal street and
highway conditions, such as hard-surfaced
roads.
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 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
motion, the transfer case will engage/disen
-
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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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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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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STARTING AND OPERATING
160
Metric Speed (km/h)
Pushing the SET (+) button once will
result in a 1 km/h increase in set speed.
Each subsequent tap of the button results
in an increase of 1 km/h.
If the button is continually pushed, the set
speed will continue to increase in 10 km/
h increments until the button is released.
The increase in set speed is reflected in
the instrument cluster display.
To Decrease Speed
While ACC is set, the set speed can be
decreased by pushing the SET (-) button.
The driver's preferred units can be selected
through the instrument panel settings. Refer
to “Getting To Know Your Instrument Panel”
in the Owner’s Manual for more information.
The speed increment shown is dependent on
the chosen speed unit of U.S. (mph) or
Metric (km/h):
U.S. Speed (mph)
Pushing the SET (-) button once will result
in a 1 mph decrease in set speed. Each
subsequent tap of the button results in a
decrease of 1 mph.
If the button is continually pushed, the set
speed will continue to decrease in 5 mph
decrements until the button is released.
The decrease in set speed is reflected in
the instrument cluster display.
Metric Speed (km/h)
Pushing the SET (-) button once will result
in a 1 km/h decrease in set speed. Each
subsequent tap of the button results in a
decrease of 1 km/h.
If the button is continually pushed, the set
speed will continue to decrease in 10 km/
h decrements until the button is released.
The decrease in set speed is reflected in
the instrument cluster display.
NOTE:
When you override and push the SET (+)
button or SET (-) buttons, the new set
speed will be the current speed of the
vehicle.
When you use the SET (-) button to decel -
erate, if the engine’s braking power does
not slow the vehicle sufficiently to reach
the set speed, the brake system will auto-
matically slow the vehicle.
The ACC system applies the brake down to
a full stop when following a target vehicle.
If an ACC host vehicle follows a target
vehicle to a standstill, the host vehicle will
release the vehicle brakes two seconds
after coming to a full stop.
The ACC system maintains set speed when
driving uphill and downhill. However, a
slight speed change on moderate hills is
normal. In addition, downshifting may
occur while climbing uphill or descending
downhill. This is normal operation and
necessary to maintain set speed. When
driving uphill and downhill, the ACC
system will cancel if the braking tempera-
ture exceeds normal range (overheated).
Setting The Following Distance In ACC
The specified following distance for ACC can
be set by varying the distance setting
between four bars (longest), three bars
(long), two bars (medium) and one bar
(short). Using this distance setting and the
vehicle speed, ACC calculates and sets the
distance to the vehicle ahead. This distance
setting displays in the instrument cluster
display.
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IN CASE OF EMERGENCY
186
F24– –Spare
F25 –10 Amp Red Module Shift By Wire (MOD_SBW)
(*)
F26 40 Amp Green –Central Body Controller (CBC) 2-EXTERIOR LIGHTS #1
F27 30 Amp Pink –
Front Wipers
F28 40 Amp Green –Central Body Controller (CBC) 3-POWER LOCKS
F29 40 Amp Green –Central Body Controller (CBC) 4-EXTERIOR LIGHTS #2
F30 – –Spare
F31 –10 Amp Red DIAGNOSTIC PORT
(*)
F32 –10 Amp Red Heating Ventilation Air Conditioning Mod (HVAC CTRL MOD)/
Steering Column Lock (SCL)/Occupant Classification Module
(OCM)/Driver Presence Detection Module (DPDM)
(*)
F33 –10 Amp Red ParkTronics System (PTS)/Infrared Camera Module (IRCM)/
Airbag Disable Lamps (AIRBAG DISABLE LMPS)
(*)
F34 –10 Amp Red Electronic Stability Control (ESC)/Electric Hydraulic Power
Steering (EHPS)/Smart Bar Control Module (SBCM) WAKE
UP
(*)
F35 30 Amp Pink –BRAKE VAC PMP — If Equipped
(*)
F36 30 Amp Pink –TRAILER TOW MOD — If Equipped
F37 30 Amp Pink –TRAILER TOW CONN 7W — If Equipped
Cavity Cartridge Fuse Micro Fuse Description
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211
Once A Month Or Before A Long Trip
Check the engine oil level about five
minutes after a fully warmed engine is
shut off. Checking the oil level while the
vehicle is on level ground will improve the
accuracy of the oil level reading. Add oil
only when the level is at or below the ADD
or MIN mark.
Check the windshield washer solvent and
add if required.
Check tire pressure and look for unusual
wear or damage. Rotate tires at the first
sign of irregular wear.
Inspect the battery and clean and tighten
the terminals as required.
Check the fluid levels of coolant reservoir,
brake master cylinder and power steering
and fill as needed.
Check all lights and other electrical items
for correct operation.At Each Oil Change
Change the engine oil filter.
Inspect the brake hoses and lines.
Inspect the CV/Universal joints.
Check tire pressure and look for unusual
wear or damage. Rotate tires at the first
sign of irregular wear, even if it occurs
before the oil indicator system turns on.
Required Maintenance Intervals
Refer to the Maintenance Plan on the
following pages for the required maintenance
intervals.
Maintenance Plan
NOTE:
Once you have carried out the last interven -
tion in the table, continue with the sched -
uled servicing, maintaining the frequency
indicated in the plan by marking each oper -
ation with a dot or dedicated note. Simply
restarting the maintenance from the start of
the plan may cause the allowed interval to be
exceeded for some operations.
CAUTION!
Failure to perform the required
maintenance items may result in damage
to the vehicle.
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217
Once A Month Or Before A Long Trip
Check engine oil level.
Check windshield washer fluid level.
Check tire pressure and look for unusual
wear or damage. Rotate tires at the first
sign of irregular wear, even if it occurs
before the oil indicator system turns on.

Check the fluid levels of the coolant reservoir
and brake master cylinder, fill as needed.

Check function of all interior and exterior lights.Demanding Vehicle Use
Restore additive level for AdBlue® Diesel
emissions (UREA) (if equipped), when the
lamp is illuminated or the message on the
instrument panel.
Maintenance Plan — Diesel Engine
Required Maintenance Intervals
Refer to the maintenance plan on the
following pages for the required maintenance
intervals.
NOTE:
Once you have carried out the last intervention in the table, continue with the scheduled servicing, maintaining the frequency indicated in
the plan by marking each operation with a dot or dedicated note. Simply restarting the maintenance from the start of the plan may cause the
allowed interval to be exceeded for some operations.
CAUTION!

Failure to perform the required maintenance
items may result in damage to the vehicle.

At Every Oil Change Interval As Indicated By Oil Change Indicator System:
Change oil and filter
Rotate the tires. Rotate at the first sign of irregular wear, even if it occurs before the oil indicator system turns on
Inspect battery and clean and tighten terminals as required
Inspect the CV/Universal joints
Inspect brake pads, shoes, rotors, drums, hoses and park brake
Inspect engine cooling system protection and hoses
Inspect exhaust system
Inspect engine air cleaner if using in dusty or off-road conditions
Inspect all door latches for presence of grease, reapply if necessary.
Inspect coolant level.
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