2023 JEEP GRAND CHEROKEE catalytic converter

112GETTING TO KNOW YOUR INSTRUMENT PANEL
Electronic Stability Control (ESC) OFF
Warning Light — If Equipped
This warning light indicates the ESC is off.
Each time the ignition is turned to ON/
RUN, the ESC system will be on, even if it
was turned off previously.
Service Active Lane Management Warning
Light — If Equipped
This warning light will illuminate when the
Active Lane Management system is not
operating and requires service. Please
see an authorized dealer.
Active Lane Management Warning Light —
If Equipped
The Active Lane Management Warning
Light will be solid yellow when the vehicle
is approaching a lane marker. The
warning light will flash when the vehicle is
crossing the lane marker Ú page 171.
Fuel Level Sensor Failure Warning Light
This warning light will illuminate along
with a dedicated message on the display
if a problem is detected with the Fuel
Level Sensor. If this light comes on see
an authorized dealer immediately.
Low Fuel Warning Light
When the fuel level reaches
approximately 2 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 337.
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.
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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GETTING TO KNOW YOUR INSTRUMENT PANEL117
Selec-Speed Control Indicator Light —
If Equipped
This light will turn on when Selec-Speed
Control is activated.
To activate Selec-Speed Control, assure
the vehicle is 4WD Low and push the button on the
Instrument Panel Ú page 134.
NOTE:If the vehicle is not in 4WD Low, “To Enter
Selec-Speed Shift to 4WD Low” will appear in the
instrument cluster display.
BLUE INDICATOR LIGHTS
High Beam Indicator Light
This indicator light will illuminate to
indicate that the high beam headlights
are on. With the low beams activated,
push the multifunction lever forward
(toward the front of the vehicle) to turn on the high
beams. Pull the multifunction lever rearward
(toward the rear of the vehicle) to turn off the high
beams. If the high beams are off, pull the lever
toward you for a temporary high beam on, “flash to
pass” scenario.
GRAY INDICATOR LIGHTS
Night Vision Suppressed Indicator Light —
If Equipped
This light alerts the driver that the Night
Vision Warning System status is
Suppressed Ú page 177.
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 government
regulations.
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 driveable 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 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 203.
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.3

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122STARTING AND OPERATING
4. If the engine fails to start after eight attempts, allow the starter to cool for at least
10 minutes, then repeat the Extended Park
Starting procedure.
IF ENGINE FAILS TO START
If the engine fails to start after you have followed
the “Normal Starting” procedure and has not
experienced an Extended Park condition as
defined previously, it may be flooded. Push the
accelerator pedal all the way to the floor and hold
it there while the engine is cranking. This should
clear any excess fuel in case the engine is flooded.
The starter motor will engage automatically, run for
10 seconds, and then disengage. Once this occurs,
release the accelerator pedal and brake pedal,
wait 10 to 15 seconds, then repeat the “Normal
Starting” procedure.
COLD WEATHER OPERATION
(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.
AFTER STARTING
The idle speed is controlled automatically, and it
will decrease as the engine warms up.
ENGINE BREAK-IN RECOMMENDATIONS
A long break-in period is not required for the engine
and drivetrain (transmission and axle) in your
vehicle.
Drive moderately during the first 300 miles
(500 km). After the initial 60 miles (100 km),
speeds up to 50 or 55 mph (80 or 90 km/h) are
desirable.
Brief full-throttle acceleration within the limits of
local traffic laws contributes to a good break-in.
Wide-open throttle acceleration in low gear can be
detrimental and should be avoided.
The engine oil installed in the engine at the factory
is a high-quality energy conserving type lubricant.
Oil changes should be consistent with anticipated
climate conditions under which vehicle operations
will occur Ú page 338.
CAUTION!
To prevent damage to the starter, do not crank
continuously for more than 10 seconds at a
time. Wait 10 to 15 seconds before trying again.
WARNING!
Never pour fuel or other flammable liquid into
the throttle body air inlet opening in an
attempt to start the vehicle. This could result
in flash fire causing serious personal injury.
Do not attempt to push or tow your vehicle to
get it started. Vehicles equipped with an auto -
matic transmission cannot be started this
way. Unburned fuel could enter the catalytic
converter and once the engine has started,
ignite and damage the converter and vehicle.
If the vehicle has a discharged battery,
booster cables may be used to obtain a start
from a booster battery or the battery in
another vehicle. This type of start can be
dangerous if done improperly Ú page 320.
CAUTION!
To prevent damage to the starter, do not
continuously crank the engine for more than 10
seconds at a time. Wait 10 to 15 seconds before
trying again.

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346SERVICING AND MAINTENANCE
(Continued)
(Continued) Under normal operating conditions, the catalytic
converter will not require maintenance. However, it
is important to keep the engine properly tuned to
ensure proper catalyst operation and prevent
possible catalyst damage.
NOTE:Intentional tampering with emissions control
systems can result in civil penalties being
assessed against you.
In unusual situations involving grossly
malfunctioning engine operation, a scorching odor
may suggest severe and abnormal catalyst
overheating. If this occurs, stop the vehicle, turn off
the engine and allow it to cool. Service, including a
tune-up to manufacturer's specifications, should
be obtained immediately. To minimize the possibility of catalytic converter
damage:
Do not interrupt the ignition when the transmis
-
sion is in gear and the vehicle is in motion.
Do not try to start the vehicle by pushing or
towing the vehicle.
Do not idle the engine with any ignition compo -
nents disconnected or removed, such as when
diagnostic testing, or for prolonged periods
during very rough idle or malfunctioning oper -
ating conditions.
COOLING SYSTEM
WARNING!
Exhaust gases can injure or kill. They contain
Carbon Monoxide (CO), which is colorless and
odorless. Breathing it can make you uncon -
scious and can eventually poison you. To
avoid breathing CO Ú page 303.
A hot exhaust system can start a fire if you
park over materials that can burn. Such mate -
rials might be grass or leaves coming into
contact with your exhaust system. Do not park
or operate your vehicle in areas where your
exhaust system can contact anything that can
burn.
CAUTION!
The catalytic converter requires the use of
unleaded fuel only. Leaded gasoline will
destroy the effectiveness of the catalyst as an
emissions control device and may seriously
reduce engine performance and cause
serious damage to the engine.
Damage to the catalytic converter can result if
your vehicle is not kept in proper operating
condition. In the event of engine malfunction,
particularly involving engine misfire or other
apparent loss of performance, have your
vehicle serviced promptly. Continued opera -
tion of your vehicle with a severe malfunction
could cause the converter to overheat,
resulting in possible damage to the converter
and vehicle.
CAUTION!
WARNING!
You or others can be badly burned by hot
engine coolant (antifreeze) or steam from your
radiator. If you see or hear steam coming from
under the hood, do not open the hood until the
radiator has had time to cool. Never open a
cooling system pressure cap when the radi -
ator or coolant bottle is hot.
Keep hands, tools, clothing, and jewelry away
from the radiator cooling fan when the hood is
raised. The fan starts automatically and may
start at any time, whether the engine is
running or not.

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TECHNICAL SPECIFICATIONS399
(Continued)
METHYLCYCLOPENTADIENYL
M
ANGANESE TRICARBONYL (MMT) IN
G
ASOLINE
MMT is a manganese-containing metallic additive
that is blended into some gasolines to increase
octane. Gasoline blended with MMT provides no
performance advantage beyond gasoline of the
same octane number without MMT. Gasoline
blended with MMT reduces spark plug life and
reduces emissions system performance in some
vehicles. The manufacturer recommends that
gasoline without MMT be used in your vehicle. The
MMT content of gasoline may not be indicated on
the gasoline pump; therefore, you should ask your
gasoline retailer whether the gasoline contains
MMT. MMT is prohibited in Federal and California
reformulated gasoline.
FUEL SYSTEM CAUTIONS
NOTE:Intentional tampering with the emissions control
system can result in civil penalties being assessed
against you.
CAUTION!
Follow these guidelines to maintain your
vehicle’s performance:
The use of leaded gasoline is prohibited by
Federal law. Using leaded gasoline can impair
engine performance and damage the emis -
sions control system.
An out-of-tune engine or certain fuel or ignition
malfunctions can cause the catalytic
converter to overheat. If you notice a pungent
burning odor or some light smoke, your engine
may be out of tune or malfunctioning and may
require immediate service. Contact an autho -
rized dealer for service assistance.
The use of fuel additives, which are now being
sold as octane enhancers, is not recom -
mended. Most of these products contain high
concentrations of methanol. Fuel system
damage or vehicle performance problems
resulting from the use of such fuels or addi -
tives is not the responsibility of the manufac-
turer and may void or not be covered under
the New Vehicle Limited Warranty.
CAUTION!
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