2021 JEEP WRANGLER UNLIMITED tire pressure

95

Tire Pressure Monitoring Low Pressure Warning

Should this occur, you should stop as soon as
possible and inflate the tires with low pres -
sure (those in a different color in the instru -
ment cluster graphic) to the vehicle’s
recommended cold placard pressure value.
Once the system receives the updated tire
pressures, the system will automatically
update, the pressure values in the graphic
display in the instrument cluster will return
to their original color, and the TPMS Warning
Light will turn off. NOTE:
When filling warm tires, the tire pressure
may need to be increased up to an additional
4 psi (28 kPa) above the recommended cold
placard pressure in order to turn the TPMS
Warning Light off.

The vehicle may need to be driven for up to
10 minutes above 15 mph (24 km/h) in order for
the TPMS to receive this information.
Service TPMS Warning
When a system fault is detected, the TPMS
Warning Light will flash on and off for 75
seconds and then remain on solid. The
system fault will also sound a chime. In addi
-
tion, the instrument cluster will display a
"SERVICE TIRE PRESSURE SYSTEM"
message for a minimum of five seconds and
then display dashes (--) in place of the pres -
sure value to indicate which sensor is not
being received. If the ignition is cycled, this sequence will
repeat, providing the system fault still exists.
If the system fault no longer exists, the
TPMS Warning Light will no longer flash, and
the “SERVICE TIRE PRESSURE SYSTEM”
message will no longer display, and a pres
-
sure value will display in place of the dashes.
A system fault can occur due to any of the
following:
Jamming due to electronic devices or
driving next to facilities emitting the same
radio frequencies as the TPMS sensors
Installing some form of aftermarket
window tinting that affects radio wave
signals
Lots of snow or ice around the wheels or
wheel housings
Using tire chains on the vehicle
Using wheels/tires not equipped with
TPMS sensors
2020_JEEP_JL_WRANGLER_UG_RHD_UK.book Page 95

SAFETY
96
Vehicles With Compact Spare or Non-Matching
Full Size Spare
1. The compact spare tire or non-matching full size does not have a tire pressure
monitoring sensor. Therefore, the TPMS
will not monitor the pressure in the
compact spare tire.
2. If you install the compact or non-matching full size spare tire in place
of a road tire that has a pressure below
the low-pressure warning limit, upon the
next ignition cycle, the TPMS Warning
Light will remain on and a chime will
sound. In addition, the graphic in the
instrument cluster will still display a
different color pressure value.
3. After driving the vehicle for up to 10 minutes above 15 mph (24 km/h),
the TPMS Warning Light will flash on and
off for 75 seconds and then remain on
solid. In addition, the instrument cluster
will display a “Service Tire Pressure
System” message for five seconds and
then display dashes (--) in place of the
pressure value. 4. For each subsequent ignition cycle, a
chime will sound, the TPMS Warning
Light will flash on and off for 75 seconds
and then remain on solid, and the instru -
ment cluster will display a “SERVICE
TIRE PRESSURE SYSTEM” message for
five seconds and then display dashes (--)
in place of the pressure value.
5. Once you repair or replace the original road tire and reinstall it on the vehicle in
place of the compact spare or
non-matching full size, the TPMS will
update automatically. In addition, the
TPMS Warning Light will turn off and the
graphic in the instrument cluster will
display a new pressure value instead of
dashes (--), as long as no tire pressure is
below the low-pressure warning limit in
any of the four active road tires. The
vehicle may need to be driven for up to
10 minutes above 15 mph (24 km/h) in
order for the TPMS to receive this
information. Vehicles With a Full Size Matching Spare
1. If your vehicle is equipped with a
matching full-size spare wheel and tire
assembly, it has a tire pressure moni -
toring sensor, and can be monitored by
the Tire Pressure Monitoring System
(TPMS) when swapped with a low pres -
sure road tire.
2. In the event that the matching full-size spare tire is swapped with a low pressure
road tire, the next ignition switch cycle
will still show the TPMS Warning Light to
be on, a chime to sound, and the graphic
display will still show the low tire pres -
sure value in a different color.
3. Driving the vehicle for up to 10 minutes above 15 mph (24 km/h) will turn off theTPMS Warning Light as long as none of
road tires are below the low pressure
warning threshold.
TPMS Deactivation — If Equipped
The TPMS can be deactivated if replacing all
four wheel and tire assemblies (road tires)
with wheel and tire assemblies that do not
have TPMS sensors, such as when installing
winter wheel and tire assemblies on your
vehicle.
2020_JEEP_JL_WRANGLER_UG_RHD_UK.book Page 96

97

To deactivate the TPMS, first replace all four
wheel and tire assemblies (road tires) with tires
not equipped with Tire Pressure Monitoring (TPM)
sensors. Then, drive the vehicle for 10 minutes
above 15 mph (24 km/h). The TPMS will chime,
the TPMS Warning Light will flash on and off for
75 seconds and then remain on. The instrument
cluster will display the “SERVICE TIRE PRES-
SURE SYSTEM” message and then display
dashes (--) in place of the pressure values.
Beginning with the next ignition cycle, the TPMS
will no longer chime or display the “SERVICE
TIRE PRESSURE SYSTEM” message in the
instrument cluster but dashes (--) will remain in
place of the pressure values.

To reactivate the TPMS, replace all four
wheel and tire assemblies (road tires) with
tires equipped with TPMS sensors. Then,
drive the vehicle for up to 10 minutes above
15 mph (24 km/h). The TPMS will chime,
the TPMS Warning Light will flash on and off
for 75 seconds and then turn off. The instru -
ment cluster will display the “SERVICE TIRE
PRESSURE SYSTEM” message and then
display pressure values in place of the
dashes. On the next ignition cycle the
"SERVICE TIRE PRESSURE SYSTEM"
message will no longer be displayed as long
as no system fault exists.OCCUPANT RESTRAINT
SYSTEMS
Some of the most important safety features
in your vehicle are the restraint systems:
Occupant Restraint Systems Features
Seat Belt Systems
Supplemental Restraint Systems (SRS)
Air Bags
Child Restraints
Some of the safety features described in this
section may be standard equipment on some
models, or may be optional equipment on
others. If you are not sure, ask an authorized
dealer.
Important Safety Precautions
Please pay close attention to the information
in this section. It tells you how to use your
restraint system properly, to keep you and
your passengers as safe as possible. Here are some simple steps you can take to
minimize the risk of harm from a deploying
air bag:
1. Children 12 years old and under should
always ride buckled up in the rear seat of
a vehicle with a rear seat.
Warning Label On Front Passenger Sun Visor
2. A child who is not big enough to wear the vehicle seat belt properly (Refer to “Child
Restraints” in this section for further
information) must be secured in the
appropriate child restraint or belt-posi -
tioning booster seat in a rear seating
position.
2020_JEEP_JL_WRANGLER_UG_RHD_UK.book Page 97

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)
2020_JEEP_JL_WRANGLER_UG_RHD_UK.book Page 137

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.

2020_JEEP_JL_WRANGLER_UG_RHD_UK.book Page 148

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 -
2020_JEEP_JL_WRANGLER_UG_RHD_UK.book Page 150

IN CASE OF EMERGENCY
190
F8230 Amp Pink –FUEL HTR — If Equipped
(*)
F83 60 Amp Yellow GLOW PLUG — If Equipped
(*)
F84 30 Amp Pink –UREA HTR CTRL UNIT — If Equipped
(*)
F85 –10 Amp Red PM SENSOR — If Equipped
(*)
F86 30 Amp Pink –BRAKE VAC PMP 2 — If Equipped
(*)
F87 –10 Amp Red SUPPLY/PURGING PMP — If Equipped
(*)
F88 20 Amp Blue –NOx SENSOR #1/ #2 — IF Equipped
(*)
F89 –10 Amp Red Steering Column Control Module (SCCM)/ Cruise Control
(CRUISE CTL)/Digital TV (DTV)
(*)
F90 20 Amp Blue –TRAILER TOW PARK LMP — If Equipped
F91 –20 Amp Yellow HORN
F92 40 Amp Green –HD ACCY #2 — If Equipped
(*)
F93 40 Amp Green –HD ACCY #1 — If Equipped
(*)
F94 –10 Amp Red Tire Pressure Monitor (TPM)/RF Hub system (CORAX)
(*)
F95 – –Spare
Cavity Cartridge Fuse Micro Fuse Description
2020_JEEP_JL_WRANGLER_UG_RHD_UK.book Page 190

IN CASE OF EMERGENCY
206
(Continued)
FREEING A STUCK VEHICLE
If your vehicle becomes stuck in mud, sand
or snow, it can often be moved using a
rocking motion. Turn the steering wheel right
and left to clear the area around the front
wheels. For vehicles with automatic trans-
mission, push and hold the lock button on
the gear selector. Then, shift back and forth
between DRIVE (D) and REVERSE (R), while
gently pressing the accelerator. Use the least
amount of accelerator pedal pressure that
will maintain the rocking motion, without
spinning the wheels or racing the engine.
NOTE:
For vehicles with automatic transmission:
Shifts between DRIVE and REVERSE can
only be achieved at wheel speeds of
5 mph (8 km/h) or less. Whenever the
transmission remains in NEUTRAL (N) for
more than two seconds, you must press
the brake pedal to engage DRIVE or
REVERSE.
Push the “ESC OFF” switch, to place the
Electronic Stability Control (ESC) system
in “Partial Off” mode, before rocking the
vehicle. Refer to “Electronic Brake Control
System” in “Safety” in your Owner’s Manual for further details. Once the
vehicle has been freed, push the “ESC
OFF” switch again to restore “ESC On”
mode.
WARNING!
Fast spinning tires can be dangerous.
Forces generated by excessive wheel
speeds may cause damage, or even failure,
of the axle and tires. A tire could explode
and injure someone. Do not spin your
vehicle's wheels faster than 30 mph
(48 km/h) or for longer than 30 seconds
continuously without stopping when you
are stuck and do not let anyone near a
spinning wheel, no matter what the speed.
CAUTION!
Racing the engine or spinning the wheels
may lead to transmission overheating
and failure. Allow the engine to idle with
the transmission in NEUTRAL for at
least one minute after every five
rocking-motion cycles. This will mini
-
mize overheating and reduce the risk of
clutch or transmission failure during
prolonged efforts to free a stuck vehicle.
When “rocking” a stuck vehicle by
shifting between DRIVE/SECOND GEAR
and REVERSE, do not spin the wheels
faster than 15 mph (24 km/h), or drive -
train damage may result.
Revving the engine or spinning the
wheels too fast may lead to transmission
overheating and failure. It can also
damage the tires. Do not spin the wheels
above 30 mph (48 km/h) while in gear
(no transmission shifting occurring).
CAUTION! (Continued)
2020_JEEP_JL_WRANGLER_UG_RHD_UK.book Page 206