2015 JEEP GRAND CHEROKEE catalytic converter

if the light stays on through several of your typical
driving cycles. In most situations, the vehicle will drive
normally and will not require towing.
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.
WARNING!
A malfunctioning catalytic converter, as referenced
above, can reach higher temperatures than in normal
operating conditions. This can cause a fire if you
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WARNING!(Continued)
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.
11. Temperature Gauge
The temperature gauge shows engine coolant tempera-
ture. Any reading within the normal range indicates that
the engine cooling system is operating satisfactorily.
The gauge pointer will likely indicate a higher tempera-
ture when driving in hot weather, up mountain grades,
or when towing a trailer. It should not be allowed to
exceed the upper limits of the normal operating range.
288 UNDERSTANDING YOUR INSTRUMENT PANEL

and START. To change the ignition positions without
starting the vehicle and use the accessories follow these
steps:
•Starting with the ignition in the OFF position,
•Push the ENGINE START/STOP button once to place
the ignition to the ACC position (DID will display
“ACC”),
•Push the ENGINE START/STOP button a second time
to place the ignition to the RUN position (DID will
display “ON/RUN”),
•Push the ENGINE START/STOP button a third time to
return the ignition to the OFF position (DID will
display “OFF”).Extreme Cold Weather (Below –20°F Or 29°C)
To ensure reliable starting at these temperatures, use of
an externally powered electric engine block heater (avail-
able from your authorized dealer) is recommended.
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 transmis-
sion 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.
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402 STARTING AND OPERATING

blended into some gasoline 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.
Materials Added To Fuel
All gasoline sold in the United States is required to
contain effective detergent additives. Use of additional
detergents or other additives is not needed under normal
conditions and they would result in additional cost.
Therefore, you should not have to add anything to the
fuel.
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 per-
formance and damage the emissions control sys-
tem.
•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 ser-
vice. Contact your authorized dealer for service
assistance.
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5
STARTING AND OPERATING 473

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
transmission control systems. When these systems are
operating properly, your vehicle will provide excellent
performance and fuel economy, as well as engine emis-
sions 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. Al-
though 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.
•If the MIL is flashing, while the engine is running,
severe catalytic converter damage and power loss
will soon occur. Immediate service is required.
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 that require an Inspection and Mainte-
nance (I/M), this check verifies the “Malfunction
528 MAINTAINING YOUR VEHICLE

WARNING!(Continued)
•A hot exhaust system can start a fire if you park
over materials that can burn. Such materials might
be grass or leaves coming into contact with your
exhaust system. Do not park or operate your ve-
hicle in areas where your exhaust system can con-
tact anything that can burn.
CAUTION!
•The catalytic converter requires the use of un-
leaded fuel only. Leaded gasoline will destroy the
effectiveness of the catalyst as an emissions control
device and may seriously reduce engine perfor-
mance and cause serious damage to the engine.
•Damage to the catalytic converter can result if your
vehicle is not kept in proper operating condition.
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CAUTION!(Continued)
In the event of engine malfunction, particularly
involving engine misfire or other apparent loss of
performance, have your vehicle serviced promptly.
Continued 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 con-
verter will not require maintenance. However, it is im-
portant to keep the engine properly tuned to assure
proper catalyst operation and prevent possible catalyst
damage.
NOTE:Intentional tampering with emissions control
systems can result in civil penalties being assessed
against you.
7
MAINTAINING YOUR VEHICLE 555

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 specifica-
tions, should be obtained immediately.
To minimize the possibility of catalytic converter dam-
age:
•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.Cooling System
WARNING!
•When working near the radiator cooling fan, dis-
connect the fan motor lead or turn the ignition
switch to the OFF position. The fan is temperature
controlled and can start at any time the ignition
switch is in the ON position.
•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 try to open a cooling system
pressure cap when the radiator is hot.
Coolant Checks
Check the engine coolant (antifreeze) protection every 12
months (before the onset of freezing weather, where
556 MAINTAINING YOUR VEHICLE