2009 JEEP GRAND CHEROKEE catalytic converter

the ON position before engine start. If the bulb does not
come on when turning the key from OFF to ON, have the
condition checked promptly.
Certain conditions such as a loose or missing gas cap,
poor fuel quality, etc. may illuminate the light after
engine start. The vehicle should be serviced 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.
The MIL flashes to alert you to serious conditions that
could lead to immediate loss of power or severe catalytic
converter damage. The vehicle should be serviced as
soon as possible if this occurs.
6. Airbag Warning Light
This light turns on and remains on for six to
eight seconds as a bulb check when the ignition
switch is first turned ON. If the light is not onduring starting, stays on, or turns on while driving, have
the system inspected by an authorized dealer as soon as
possible.
7. Anti-Lock Brake (ABS) Light
This light monitors the Anti-Lock Brake System
(ABS). The light will turn on when the ignition
switch is turned to the ON position and may
stay on for as long as four seconds.
If the ABS light remains on or turns on while driving, it
indicates 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 BRAKE warning light is not on.
If the ABS light is on, the brake system should be serviced
as soon as possible to restore the benefits of Anti-Lock
brakes. If the ABS light does not turn on when the
Ignition switch is turned to the ON position, have the
light inspected by an authorized dealer.
186 UNDERSTANDING YOUR INSTRUMENT PANEL

Extremely Cold Weather (Below20°F or29°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 liquids into
the throttle body air inlet opening in an attempt to
start the vehicle. This could result in a flash fire
causing serious personal injury.
(Continued)
WARNING! (Continued)
•Do not attempt to push or tow your vehicle to get
it started. Vehicles equipped with an automatic
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 dis-
charged 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 dan-
gerous if done improperly. Refer to Section 6 for
proper jump-starting procedures and follow them
carefully.
If the engine fails to start after you have followed the
“Normal Starting” or “Extreme Cold Weather” proce-
dures, it may be flooded. To clear any excess fuel, push
the accelerator pedal all the way to the floor and hold it.
Then, turn the ignition switch to the START position and
STARTING AND OPERATING 281
5

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 emission 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 if the
gasoline contains MMT.
It is even more important to look for gasoline without
MMT in Canada, because MMT can be used at levels
higher than those allowed in the United States.
MMT is prohibited in Federal and California reformu-
lated 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 normalconditions and 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 gas is prohibited by Federal law.
Using leaded gasoline can impair engine performance
and damage the emission 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 your authorized dealer for service assistance.
358 STARTING AND OPERATING

WARNING!
Commercially available windshield washer solvents
are flammable. They could ignite and burn you. Care
must be exercised when filling or working around
the washer solution.
Exhaust System
The best protection against carbon monoxide entry into
the vehicle body is a properly maintained engine exhaust
system.
If you notice a change in the sound of the exhaust system;
or if the exhaust fumes can be detected inside the vehicle;
or when the underside or rear of the vehicle is damaged;
have an authorized technician inspect the complete ex-
haust system and adjacent body areas for broken, dam-
aged, deteriorated, or mispositioned parts. Open seams
or loose connections could permit exhaust fumes to seepinto the passenger compartment. In addition, inspect the
exhaust system each time the vehicle is raised for lubri-
cation or oil change. Replace as required.
WARNING!
Exhaust gases can injure or kill. They contain carbon
monoxide (CO), which is colorless and odorless.
Breathing it can make you unconscious and can
eventually poison you. To avoid breathing CO, refer
to Exhaust Gas in the Safety Tips section of this
manual.
The catalytic converter requires the use of unleaded fuel
only. Leaded gasoline will destroy the effectiveness of the
converter as an emission control device.
422 MAINTAINING YOUR 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.
CAUTION!
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.NOTE:Intentional tampering with emissions control
systems can result in civil penalties being assessed
against you.
WARNING!
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 vehicle in areas
where your exhaust system can contact anything that
can burn.
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 tuneup to manufacturer’s specifica-
tions, should be obtained immediately.
MAINTAINING YOUR VEHICLE 423
7

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!
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 or coolant bottle is hot.
Engine Coolant Checks
Check the engine coolant (antifreeze) protection every
12 months (before the onset of freezing weather, where
applicable). If the engine coolant (antifreeze) is dirty or
rusty in appearance, the system should be drained,
flushed and refilled with fresh engine coolant (anti-
freeze). Check the front of the A/C condenser for any
424 MAINTAINING YOUR VEHICLE