2017 JEEP GRAND CHEROKEE catalytic converter

Hood Open Warning Light
Red TelltaleLight What It Means
Hood Open Warning Light
This indicator will illuminate when the hood is ajar/open and not fully closed.
Yellow Telltale Lights
Engine Malfunction Warning Light
Yellow Telltale
Light What It Means
Engine Check/Malfunction Indicator 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. The light will illu-
minate when the ignition is in the ON position before engine start. If the bulb does not come on
when placing the ignition in the ON/RUN position, 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 im-
mediate loss of power or severe catalytic converter damage. The vehicle should be serviced as
soon as possible if this occurs.
158 GETTING TO KNOW YOUR INSTRUMENT PANEL

WARNING!
A malfunctioning catalytic converter, as referenced
above, 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 engine
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 PANEL 159

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 automatic trans-
mission 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 drivable and not need towing, see
your authorized dealer for service as soon as possible.
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.
(Continued)
CAUTION! (Continued)
•If the MIL is flashing while the engine is running,
severe catalytic converter damage and power loss
will soon occur. Immediate service is required.
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 ac-
cess this information to assist with the diagnosis and
service of your vehicle and emissions system.
WARNING!
• ONLY an authorized service technician should con-
nect equipment to the OBD II connection port in
order to 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
(Continued)
176 GETTING TO KNOW YOUR INSTRUMENT PANEL

After Starting
The idle speed is controlled automatically, and it will
decrease as the engine warms up.
If Engine Fails To Start
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 automatic trans-
mission 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. Refer to
“Jump-Starting Procedures” in “In Case Of Emer-
gency” for further information.
After Starting
The idle speed is controlled automatically, and it will
decrease as the engine warms up.
STOP/START SYSTEM — IF EQUIPPED
The Stop/Start function is developed to reduce fuel con-
sumption. 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.
Automatic Mode
The Stop/Start feature is enabled after every
normal customer engine start. At that time, the
system will go into STOP/START READY and if
all other conditions are met, can go into a STOP/
START AUTOSTOP ACTIVE “Autostop” mode.
To Activate The Autostop Mode, The Following Must Occur:
• The system must be in STOP/START READY state. A
STOP/START READY message will be displayed in the
instrument cluster display within the Stop/Start section.
Refer to “Instrument Cluster Display” in “Getting To
Know Your Instrument Panel” for further information.
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STARTING AND OPERATING 267

CAUTION!
•The catalytic converter requires the use of unleaded
fuel only. Leaded gasoline will destroy the effective-
ness 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 involv-
ing engine misfire or other apparent loss of perfor-
mance, have your vehicle serviced promptly. Contin-
ued operation of your vehicle with a severe
malfunction could cause the converter to overheat,
resulting in possible damage to the converter and
vehicle.
Under normal operating conditions, the catalytic converter
will not require maintenance. However, it is important to
keep the engine properly tuned to assure proper catalyst
operation and prevent possible catalyst damage. NOTE:
Intentional tampering with emissions control sys-
tems 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 shut off the engine or interrupt the ignition,
when the transmission is in gear and the vehicle is in
motion.
• Do not try to start the engine by pushing or towing the
vehicle.
• Do not idle the engine with any spark plug wires
disconnected or removed, such as when diagnostic
testing, or for prolonged periods during very rough idle
or malfunctioning operating conditions.
466 SERVICING AND MAINTENANCE

MMT In Gasoline
Methylcyclopentadienyl Manganese Tricarbonyl (MMT) is
a manganese-containing metallic additive that is blended
into some gasoline to increase octane. Gasoline blended
with MMT provides no performance advantage beyond
gasoline of the same octane number without MMT. Gaso-
line 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
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 perfor-
mance and damage the emissions control system.
(Continued)
CAUTION! (Continued)
•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 your authorized dealer for service assistance.
• The use of fuel additives, which are now being sold
as octane enhancers, is not recommended. Most of
these products contain high concentrations of metha-
nol. Fuel system damage or vehicle performance
problems resulting from the use of such fuels or
additives is not the responsibility of the manufac-
turer and may void or not be covered under the New
Vehicle Limited Warranty.
NOTE: Intentional tampering with the emissions control
system can result in civil penalties being assessed against
you.
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TECHNICAL SPECIFICATIONS 509