2020 JEEP WRANGLER UNLIMITED service

77
(Continued)
(Continued)
ONBOARD DIAGNOSTIC
SYSTEM — OBD II
Your vehicle is equipped with a sophisticated
Onboard Diagnostic system called OBD II.
This system monitors the performance of the
emissions, engine, and transmission control
systems. When these systems are operating
properly, your vehicle will provide excellent
performance and fuel economy, as well as
engine emissions well within current govern -
ment regulations.
If any of these systems require service, the
OBD II system will turn on the Malfunction
Indicator Light (MIL). It will also store diag -
nostic codes and other information to assist
your service technician in making repairs.
Although your vehicle will usually be drive -
able and not need towing, see an authorized
dealer for service as soon as possible.
Onboard Diagnostic System (OBD II)
Cybersecurity
Your vehicle is required to have an Onboard
Diagnostic system (OBD II) and a connection
port to allow access to information related to
the performance of your emissions controls.
Authorized service technicians may need to
access this information to assist with the
diagnosis and service of your vehicle and
emissions system. For further information, refer to “Cybersecu-
rity” in “Multimedia” in your Owner’s
Manual.
CAUTION!
Prolonged driving with the MIL on could
cause further damage to the emission
control system. It could also affect fuel
economy and driveability. The vehicle
must be serviced before any emissions
tests can be performed.
If the MIL is flashing while the vehicle is
running, severe catalytic converter
damage and power loss will soon occur.
Immediate service is required.
WARNING!
ONLY an authorized service technician
should connect equipment to the OBD II
connection port in order to read the VIN,
diagnose, or service your vehicle.
CAUTION! (Continued)
If unauthorized equipment is connected
to the OBD II connection port, such as a
driver-behavior tracking device, it may:
Be possible that vehicle systems, including safety related systems,could be impaired or a loss of vehicle
control could occur that may result in
an accident involving serious injury
or death.
Access, or allow others to access, information stored in your vehicle
systems, including personal informa-
tion.
WARNING! (Continued)
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79
If the “Anti-Lock Brake Warning Light”
remains on or comes on while driving, it indi-
cates that the anti-lock portion of the brake
system is not functioning and that service is
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 placed in the ON/RUN mode, have
the light repaired as soon as possible.
Electronic Brake Control (EBC) System

Your vehicle is equipped with an advanced
Electronic Brake Control (EBC) system. This
system includes Electronic Brake Force Distri -
bution (EBD), Anti-Lock Brake System (ABS),
Brake Assist System (BAS), Hill Start Assist
(HSA), Traction Control System (TCS), Elec-
tronic Stability Control (ESC), and Electronic
Roll Mitigation (ERM). These systems work
together to enhance both vehicle stability and
control in various driving conditions.
Your vehicle may also be equipped with
Trailer Sway Control (TSC), Ready Alert
Braking (RAB), Rain Brake Support (RBS),
and Hill Descent Control (HDC).
Brake System Warning Light
The red “Brake System Warning Light” will
turn on when the ignition is placed in 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 indi
-
cates that the brake system is not func -
tioning properly and that immediate service
is required. If the “Brake System Warning
Light” does not come on when the ignition is
placed in the ON/RUN mode, have the light
repaired as soon as possible.
Brake Assist System (BAS)
The Brake Assist System (BAS) is designed
to optimize the vehicle’s braking capability
during emergency braking maneuvers. The
system detects an emergency braking situa -
tion by sensing the rate and amount of brake
application and then applies optimum pres -
sure to the brakes. This can help reduce
braking distances. The BAS complements
the Anti-Lock Brake System (ABS). Applying the brakes very quickly results in the best
BAS assistance. To receive the benefit of the
system, you must apply continuous braking
pressure during the stopping 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
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
manner, which could jeopardize the user's
safety or the safety of others.
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88
The BSM system notifies the driver of
objects in the detection zones by illumi-
nating the BSM warning light located in the
outside mirrors in addition to sounding an
audible (chime) alert and reducing the radio
volume. Refer to “Modes Of Operation” for
further information.
The BSM system monitors the detection
zone from three different entry points (side,
rear, front) while driving to see if an alert is
necessary. The BSM system will issue an
alert during these types of zone entries.
Entering From The Side
Vehicles that move into your adjacent lanes
from either side of the vehicle.
Entering From The Rear
Vehicles that come up from behind your
vehicle on either side and enter the rear
detection zone with a relative speed of less
than 30 mph (48 km/h).
Overtaking Traffic
If you pass another vehicle slowly with a rela -
tive speed less than 15 mph (24 km/h) and
the vehicle remains in the blind spot for
approximately 1.5 seconds, the warning light will be illuminated. If the difference in speed
between the two vehicles is greater than
15 mph (24 km/h), the warning light will not
illuminate.
The BSM system is designed not to issue an
alert on stationary objects such as guardrails,
posts, walls, foliage, berms, etc. However,
occasionally the system may alert on such
objects. This is normal operation and your
vehicle does not require service.
The BSM system will not alert you of objects
that are traveling in the opposite direction of
the vehicle in adjacent lanes.Rear Cross Path (RCP)
The Rear Cross Path (RCP) feature is
intended to aid the driver when backing out
of parking spaces where their vision of
oncoming vehicles may be blocked. Proceed
slowly and cautiously out of the parking
space until the rear end of the vehicle is
exposed. The RCP system will then have a
clear view of the cross traffic and if an
oncoming vehicle is detected, alert the
driver.
RCP monitors the rear detection zones on
both sides of the vehicle, for objects that are
moving toward the side of the vehicle with a
minimum speed of approximately 3 mph
(5 km/h), to objects moving a maximum of
approximately 20 mph (32 km/h), such as in
parking lot situations.
NOTE:
In a parking lot situation, oncoming vehicles
can be obscured by vehicles parked on either
side. If the sensors are blocked by other
structures or vehicles, the system will not be
able to alert the driver.
When RCP is on and the vehicle is in
REVERSE (R), the driver is alerted using
both the visual and audible alarms, including
reducing the radio volume.
WARNING!
The Blind Spot Monitoring system is only
an aid to help detect objects in the blind
spot zones. The BSM system is not
designed to detect pedestrians, bicyclists,
or animals. Even if your vehicle is
equipped with the BSM system, always
check your vehicle’s mirrors, glance over
your shoulder, and use your turn signal
before changing lanes. Failure to do so can
result in serious injury or death.
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92
FCW Limited Warning
If the instrument cluster displays “ACC/FCW
Limited Functionality” or “ACC/FCW Limited
Functionality Clean Front Windshield”
momentarily, there may be a condition that
limits FCW functionality. Although the
vehicle is still drivable under normal condi-
tions, the active braking may not be fully
available. Once the condition that limited
the system performance is no longer present,
the system will return to its full performance
state. If the problem persists, see an autho -
rized dealer.
Service FCW Warning
If the system turns off, and the instrument
cluster displays:
ACC/FCW Unavailable Service Required
Cruise/FCW Unavailable Service Required
This indicates there is an internal system
fault. Although the vehicle is still drivable
under normal conditions, have the system
checked by an authorized dealer.
FCW Sensor Protective Cover
Your vehicle is equipped with a protective
cover that is to be used whenever the wind -
shield is folded down in order to protect the
FCW sensor. To install the cover, follow the
instructions below.
1. Secure the top part of the cover so that it hinges to the header.
2. Swing the cover down and push on it so that it covers the opening.
3. Check to make sure the cover is secured properly.
NOTE:
Be sure to remove the cover before returning
the windshield to the normal position. Store
the cover in the cargo area.
Cleaning Instructions
During windshield down applications, dust/
dirt can accumulate in the cover and block
the camera lens. Use a microfiber cloth to
clean the camera lens, module, and inside
cover, being careful not to damage or scratch
the module.
Tire Pressure Monitoring System (TPMS)
The Tire Pressure Monitoring System (TPMS)
will warn the driver of a low tire pressure
based on the vehicle recommended cold
placard pressure.
NOTE:
The alert warning on the cluster will stay
on until the tire is inflated to the placard
pressure.
The system only warns the tire pressure is
low: it is not able to inflate them.
The tire pressure will vary with temperature
by approximately 1 psi (7 kPa) for every 12°F
(6.5°C). This means that when the outside
temperature decreases, the tire pressure will
decrease. Tire pressure should always be set
based on cold inflation tire pressure. This is
defined as the tire pressure after the vehicle
has not been driven for at least three hours,
or driven less than 1 mile (1.6 km) after a
three hour period. The cold tire inflation
pressure must not exceed the maximum
inflation pressure molded into the tire side -
wall. Refer to “Tires” in “Servicing And
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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
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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.
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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.
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SAFETY
98
(Continued)
3. If a child from 2 to 12 years old (not in arear-facing child restraint) must ride in
the front passenger seat, move the seat
as far back as possible and use the
proper child restraint. Refer to “Child
Restraints” in this section for further
information.
4. Never allow children to slide the shoulder belt behind them or under their arm.
5. You should read the instructions provided with your child restraint to make
sure that you are using it properly.
6. All occupants should always wear their lap and shoulder belts properly.
7. The driver and front passenger seats should be moved back as far as practical
to allow the front air bags room to inflate.
8. Do not lean against the door or window. If your vehicle has side air bags, and
deployment occurs, the side air bags will
inflate forcefully into the space between
occupants and the door and occupants
could be injured. 9. If the air bag system in this vehicle needs
to be modified to accommodate a
disabled person, refer to the “Customer
Assistance” section for customer service
contact information.
Seat Belt Systems
Buckle up even though you are an excellent
driver, even on short trips. Someone on the
road may be a poor driver and could cause a
collision that includes you. This can happen
far away from home or on your own street.
Research has shown that seat belts save
lives, and they can reduce the seriousness of
injuries in a collision. Some of the worst inju -
ries happen when people are thrown from the
vehicle. Seat belts reduce the possibility of
ejection and the risk of injury caused by
striking the inside of the vehicle. Everyone in
a motor vehicle should be belted at all times.
WARNING!

NEVER use a rearward facing child restraint
on a seat protected by an ACTIVE AIRBAG in
front of it, DEATH or SERIOUS INJURY to
the CHILD can occur.

It is advisable to always carry children in
a child restraint system on the rear seat,
which is the most protected position in
the event of a collision.
Should it be necessary to carry a child on
the passenger side front seat in a
rear-facing child restraint system, the
passenger side front air bag must be
deactivated. Always make sure the
airbag deactivation indicator light is illu -
minated when using a child restraint
system. The passenger seat must also be
positioned backward as far as possible to
avoid the child restraint system from
coming into contact with the dashboard.
A deploying passenger front air bag can
cause death or serious injury to a child
12 years or younger, including a child in
a rear-facing child restraint.
WARNING! (Continued)
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