2023 JEEP GLADIATOR check engine

134GETTING TO KNOW YOUR INSTRUMENT PANEL
Oil Pressure Warning Light
This warning light will illuminate, and a
chime will sound, to indicate low engine
oil pressure. If the light and chime turn on
while driving, safely stop the vehicle and
turn off the engine as soon as possible. After the
vehicle is safely stopped, restart the engine and
monitor the Oil Pressure Warning Light. If the Oil
Pressure Warning Light is still illuminated, turn the
engine OFF and contact an authorized dealer for
further assistance. Do not operate the vehicle until
the cause is corrected. If the light is no longer
illuminated, the engine can be operated but it is
recommended to take the vehicle to an authorized
dealer as soon as possible.
Do not operate the vehicle until the cause is
corrected. This light does not indicate how much oil
is in the engine. The engine oil level must be
checked under the hood.
Oil Temperature Warning Light
This warning light will illuminate to
indicate the engine oil temperature is
high. If the light turns on while driving,
stop the vehicle and shut off the engine
as soon as possible. Wait for oil temperature to
return to normal levels.
Seat Belt Reminder Warning Light
This warning light indicates when the
driver or passenger seat belt is
unbuckled. When the ignition is first
placed in the ON/RUN or ACC/ON/RUN
position and if the driver’s seat belt is unbuckled,
a chime will sound and the light will turn on. When
driving, if the driver or front passenger seat belt
remains unbuckled, the Seat Belt Reminder Light
will flash or remain on continuously and a chime
will sound Ú page 299.
Rear Seat Belt Reminder Indicator Light —
If Equipped With A Base Instrument
Cluster
This light indicates when a rear seat belt
is unbuckled in the second row. When
the ignition is first placed in the ON/RUN
or ACC/ON/RUN position, and if a seat
belt in the second row is unbuckled, a light
corresponding to the specific seat will turn on in
the upper right portion of the instrument cluster
display, momentarily replacing the configurable
corner information. If a second row seat belt that
was buckled at the start of the trip is unbuckled,
the Rear Seat Belt Reminder Light will change from
the buckled to the unbuckled symbol, and a chime
will sound Ú page 299.
Transmission Temperature Warning
Light — If Equipped

This warning light will illuminate to warn of
a high transmission fluid temperature.
This may occur with strenuous usage such
as trailer towing. If this light turns on, stop
the vehicle and run the engine at idle or slightly
faster, with the transmission in PARK (P) or NEUTRAL
(N), until the light turns off. Once the light turns off,
you may continue to drive normally. If Manual
transmission equipped, this warning will illuminate
to warn of high clutch temperature. This may occur
with driver misuse of clutch pedal or resting foot on
the clutch pedal or partially engaging the clutch for
longer duration. If the light turns on, it will be with an
additional CLUTCH HOT message. Stop the vehicle
safely and run the engine at idle with transmission
gear in NEUTRAL (N) until the light turns off. Once the
light turns off, follow the message displayed in the
instrument cluster.

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136GETTING TO KNOW YOUR INSTRUMENT PANEL
Electronic Stability Control (ESC) OFF
Warning Light — If Equipped
This warning light indicates the Electronic
Stability Control (ESC) is off.
Each time the ignition is turned to ON/RUN or ACC/
ON/RUN, the ESC system will be on, even if it was
turned off previously.
Loose Fuel Filler Cap Warning Light —
If Equipped
This warning light will illuminate when the
fuel filler cap is loose. Properly close the
filler cap to disengage the light. If the
light does not turn off, please see an
authorized dealer.
Low Fuel Warning Light
When the fuel level reaches
approximately 2.0 gal (7.5 L), this light
will turn on and a chime will sound. The
light will remain on until fuel is added.
Low Washer Fluid Warning Light —
If Equipped
This warning light will illuminate when the
windshield washer fluid is low
Ú page 364.
Engine Check/Malfunction Indicator
Warning Light (MIL)
The Engine Check/Malfunction Indicator
Light (MIL) is a part of an Onboard
Diagnostic System called OBD II that
monitors engine and automatic
transmission control systems. This warning light
will illuminate when the ignition is in the ON/RUN
position before engine start. If the bulb does not
come on when turning the ignition switch from OFF
to ON/RUN, have the condition checked promptly.
Certain conditions, such as a loose or missing gas
cap, poor quality fuel, etc., may illuminate the light
after engine start. The vehicle should be serviced if
the light stays on through several typical driving
styles. In most situations, the vehicle will drive
normally and will not require towing.
When the engine is running, the MIL may flash to
alert serious conditions that could lead to
immediate loss of power or severe catalytic
converter damage. The vehicle should be serviced
by an authorized dealer as soon as possible if this
occurs.
Service 4WD Warning Light — If Equipped
This warning light will illuminate to signal
a fault with the 4WD system. If the light
stays on or comes on during driving, it
means that the 4WD system is not
functioning properly and that service is required. It
is recommend you drive to the nearest service
center and have the vehicle serviced immediately.
WARNING!
A malfunctioning catalytic converter, as
previously referenced, can reach higher
temperatures than in normal operating
conditions. This can cause a fire if you drive
slowly or park over flammable substances such
as dry plants, wood, cardboard, etc. This could
result in death or serious injury to the driver,
occupants or others.
CAUTION!
Prolonged driving with the Malfunction Indicator
Light (MIL) on could cause damage to the
vehicle control system. It also could affect fuel
economy and driveability. If the MIL is flashing,
severe catalytic converter damage and power
loss will soon occur. Immediate service is
required.

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138GETTING TO KNOW YOUR INSTRUMENT PANEL
AdBlue® (UREA) Injection System Failure
Warning Light — If Equipped
This warning light will illuminate along
with a dedicated message on the display
(if equipped) if an unknown fluid not
conforming with acceptable
characteristics is inserted, or if an average
consumption of AdBlue® (UREA) over 50% is
detected. Contact an authorized dealer as soon as
possible. If the problem is not solved, a specific message will
appear on the Instrument Cluster Display
whenever a certain threshold is reached until it will
no longer be possible to start the engine.
When about 125 miles (200 km) are remaining
before the AdBlue® (UREA) tank is empty, a
continuous dedicated message will appear on the
instrument panel, accompanied by a buzzer sound
(if equipped).
YELLOW INDICATOR LIGHTS
4WD Indicator Light — If Equipped
This light alerts the driver that the vehicle
is in the four-wheel drive mode, and the
front and rear driveshafts are
mechanically locked together forcing the
front and rear wheels to rotate at the same speed.
4WD Low Indicator Light — If Equipped
This light alerts the driver that the vehicle
is in the 4WD Low mode. The front and
rear driveshafts are mechanically locked
together forcing the front and rear
wheels to rotate at the same speed. Low range
provides a greater gear reduction ratio to provide
increased torque at the wheels.
4WD Part Time Indicator Light —
If Equipped
This light alerts the driver that the vehicle
is in the four-wheel drive part time mode,
and the front and rear driveshafts are
mechanically locked together forcing the
front and rear wheels to rotate at the same speed.
Axle Locker Fault Indicator Light —
If Equipped
This light indicates when front and/or
rear axle locker fault has been detected.
Rear Axle Lock Indicator Light —
If Equipped
This light indicates when the rear axle
lock has been activated Ú page 161.
Front And Rear Axle Lock Indicator Light —
If Equipped
This light indicates when the front, rear,
or both axles have been locked. The
telltale will display the lock icon on the
front and rear axles to indicate the
current lock status.
CAUTION!
The TPMS has been optimized for the original
equipment tires and wheels. TPMS pressures
and warning have been established for the tire
size equipped on your vehicle. Undesirable
system operation or sensor damage may result
when using replacement equipment that is not
of the same size, type, and/or style. Aftermarket
wheels can cause sensor damage. Using
aftermarket tire sealants may cause the Tire
Pressure Monitoring System (TPMS) sensor to
become inoperable. After using an aftermarket
tire sealant it is recommended that you take
your vehicle to an authorized dealer to have your
sensor function checked.

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142GETTING TO KNOW YOUR INSTRUMENT PANEL
If any of these systems require service, the OBD II
system will turn on the Malfunction Indicator Light
(MIL). It will also store diagnostic codes and other
information to assist your service technician in
making repairs. Although your vehicle will usually
be drivable and not need towing, see an authorized
dealer for service as soon as possible.
ONBOARD DIAGNOSTIC SYSTEM
(OBD II) C
YBERSECURITY
Your vehicle is required to have an 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 Ú page 214.
EMISSIONS INSPECTION AND
MAINTENANCE PROGRAMS
In some localities, it may be a legal requirement to
pass an inspection of your vehicle's emissions
control system. Failure to pass could prevent
vehicle registration. For states and/or provinces that require
an Inspection and Maintenance (I/M),
this check verifies the Malfunction
Indicator Light (MIL) is functioning and is
not on when the engine is running, and that the
OBD II system is ready for testing.
The OBD II system may not be ready if your vehicle
was recently serviced, recently had a depleted
battery or a battery replacement. If the OBD II
system should be determined not ready for the I/M
test, your vehicle may fail the test.
Your vehicle has a simple ignition actuated test,
which you can use prior to going to the test station.
To check if your vehicle's OBD II system is ready,
you must do the following:

1. Cycle the ignition switch to the ON position, but do not crank or start the engine.

NOTE:If you crank or start the engine, you will have to
start this test over.
2. As soon as you cycle the ignition switch to the ON position, you will see the Malfunction
Indicator Light (MIL) symbol come on as part of
a normal bulb check.
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.
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, infor -
mation stored in your vehicle systems,
including personal information.

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GETTING TO KNOW YOUR INSTRUMENT PANEL143
3. Approximately 15 seconds later, one of two things will happen:
The MIL will flash for about 10 seconds and
then return to being fully illuminated until
you turn OFF the ignition or start the engine.
This means that your vehicle's OBD II
system is not ready and you should not
proceed to the I/M station.
The MIL will not flash at all and will remain
fully illuminated until you place the ignition
in the off position or start the engine. This
means that your vehicle's OBD II system is
ready and you can proceed to the I/M
station. If your OBD II system is
not ready, you should see
an authorized dealer or repair facility. If your
vehicle was recently serviced or had a battery
failure or replacement, you may need to do nothing
more than drive your vehicle as you normally would
in order for your OBD II system to update. A
recheck with the previously mentioned test routine
may then indicate that the system is now ready.
Regardless of whether your vehicle's OBD II system
is ready, if the MIL is illuminated during normal
vehicle operation you should have your vehicle
serviced before going to the I/M station. The I/M
station can fail your vehicle because the MIL is on
with the engine running.3

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STARTING AND OPERATING145
however the ignition will remain in the ACC
position (NOT the OFF position). Never leave a
vehicle out of the PARK position, or it could roll.
3. 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 position.
4. 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 position (NOT the OFF
position) if the engine is turned off when the
transmission is not in PARK.
NOTE:The system will automatically time out and the
ignition will cycle to the OFF position after
30 minutes of inactivity if the ignition is left in the
ACC or RUN (engine not running) position 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 position.

2. Push the ENGINE START/STOP button once to
place the ignition to the ACC position
(instrument cluster will display “ACC”).
3. Push the ENGINE START/STOP button a second time to place the ignition to the RUN
position (instrument cluster will display “ON/
RUN”).
4. Push the ENGINE START/STOP button a third time to return the ignition to the OFF position
(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 transmis
-
sion
Driver door is ajar or if the driver door is
removed and the driver is not on the seat (seat
pad sensor detects driver missing)
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 instrument cluster display and on the gear
selector. If the "P" indicator is blinking, your
vehicle is not in PARK. As an added precau -
tion, 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.
4

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146STARTING AND OPERATING
Vehicle is not in PARK
Vehicle speed is 1.2 mph (1.9 km/h) or less
Ignition is switched from ON/RUN to OFF
NOTE:For Keyless Enter ‘n Go™ equipped vehicles, the
engine will turn off and the ignition will change to
ACC position. After 30 minutes the ignition
switches to OFF automatically, unless the driver
turns the ignition OFF.
If the vehicle is not in PARK and the driver exits the
vehicle with the engine running, the vehicle may
AutoPark.
AutoPark will engage when all of these conditions
are met:
Vehicle is equipped with an 8-speed transmis -
sion
Driver door is ajar or if the driver door is
removed and the driver is not on the seat (seat
pad sensor detects driver missing)
Vehicle is not in PARK
Vehicle speed is 1.2 mph (1.9 km/h) or less
Driver seat belt is unbuckled
Brake pedal is not pressed
The message “ AutoPark Engaged Shift To P Then
Shift To Gear ” will display in the instrument cluster.
NOTE:In some cases the ParkSense graphic will be
displayed in the instrument cluster. In these cases,
the gear selector must be returned to “P” to select
desired gear.
If the driver shifts into PARK while moving, the
vehicle may AutoPark.
AutoPark will engage ONLY when vehicle speed is
1.2 mph (1.9 km/h) or less.
The message “ Vehicle Speed Is Too High To Shift
To P ” will be displayed in the instrument cluster if
vehicle speed is above 1.2 mph (1.9 km/h).
4WD LOW
AutoPark will be disabled when operating the
vehicle in 4WD LOW.
The message “ AutoPark Disabled ” will be
displayed in the instrument cluster. Additional customer warnings will be given when
both of these conditions are met:
Vehicle is not in PARK
Driver’s door is ajar
The message “ AutoPark Not Engaged” will be
displayed in the instrument cluster. A warning
chime will continue until you shift the vehicle into
PARK or the driver’s door is closed.
ALWAYS DO A VISUAL CHECK
that your vehicle is in
PARK by looking for the “P” in the instrument
cluster display and on the gear selector. As an
added precaution, always apply the parking brake
when exiting the vehicle.
EXTREME COLD WEATHER
(B
ELOW –22°F OR −30°C)
To ensure reliable starting at these temperatures,
use of an externally powered electric engine block
heater (available from an authorized dealer) is
recommended.
EXTENDED PARK STARTING
NOTE:Extended Park condition occurs when the vehicle
has not been started or driven for at least 30 days.

1. Install a battery charger or jumper cables to
the battery to ensure a full battery charge
during the crank cycle.

WARNING!

If vehicle speed is above 1.2 mph (1.9 km/h), the
transmission will default to NEUTRAL until the
vehicle speed drops below 1.2 mph (1.9 km/h). A
vehicle left in the NEUTRAL position can roll. As
an added precaution, always apply the parking
brake when exiting the vehicle.

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STARTING AND OPERATING149
(Continued)
3. The system will automatically engage the
starter to crank the engine. If the vehicle fails
to start, the starter will disengage automat-
ically after 25 seconds.
4. If you wish to stop the cranking of the engine prior to the engine starting, push the ENGINE
START/STOP button again.
5. Check that the Oil Pressure Warning Light has turned off.
6. Release the parking brake.
STARTING FLUIDS
The engine is equipped with a glow plug preheating
system. If the instructions in this manual are
followed, the engine should start in all conditions
and no type of starting fluid should be used.
NORMAL OPERATION — DIESEL ENGINE
Observe the following when the diesel engine is
operating:
All message center lights are off.
Malfunction Indicator Light (MIL) is off.
Engine Oil Pressure telltale is not illuminated.
Voltmeter operation.
The voltmeter may show a gauge fluctuation at
various engine temperatures. This is caused by the
glow plug heating system. The number of cycles
and the length of the cycling operation is controlled by the engine control module. Glow plug heater
operation can run for several minutes. Once the
heater operation is complete the voltmeter needle
will stabilize.
COLD WEATHER PRECAUTIONS
Operation in ambient temperature below 32°F
(0°C) may require special considerations. The
following charts suggest these options:
Fuel Operating Range
NOTE:Use Ultra Low Sulfur Diesel (ULSD) Fuels
ONLY.

Fuel Operating Range Chart

*Number 1 ULSD Fuel should only be used where
extended arctic conditions 0°F (-18°C) exist.
WARNING!
Do not leave children or animals inside parked
vehicles in hot weather. Interior heat build-up
may cause serious injury or death.
When leaving the vehicle, always make sure
the keyless ignition node is in the OFF posi -
tion, remove the key fob from the vehicle and
lock the vehicle.
Never leave children alone in a vehicle, or with
access to an unlocked vehicle. Allowing chil -
dren to be in a vehicle unattended is
dangerous for a number of reasons. A child or
others could be seriously 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, and do
not leave the ignition of a vehicle equipped
with Keyless Enter ‘n Go™ in the ACC or ON/
RUN position. A child could operate power
windows, other controls, or move the vehicle.
WARNING!
4

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