2006 JEEP GRAND CHEROKEE catalytic converter

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 Malfunction Indicator Light 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. (See
page 347 for more information.)6. Airbag Warning Light
This light turns on and remains on for 6 to 8
seconds as a bulb check when the ignition
switch is first turned ON. If the light is not on
during starting, stays on, or turns on while
driving, have the system inspected by an authorized
dealer as soon as possible.
7. Anti-Lock Brake Warning Light
This light monitors the Anti-Lock Brake System.
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.
UNDERSTANDING YOUR INSTRUMENT PANEL 181
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•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 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 methanol.
Fuel system damage or vehicle performance problems
resulting from the use of such fuels or additives is not
the responsibility of the manufacturer.
NOTE:Intentional tampering with emissions control
systems can result in civil penalties being assessed
against you.
Carbon Monoxide Warnings
WARNING!
Carbon monoxide (CO) in exhaust gases is deadly.
Follow the precautions below to prevent carbon
monoxide poisoning:
•Do not inhale exhaust gases. They contain carbon
monoxide, a colorless and odorless gas which can kill.
Never run the engine in a closed area, such as a
garage, and never sit in a parked vehicle with the
engine running for an extended period. If the vehicle is
stopped in an open area with the engine running for
more than a short period, adjust the ventilation system
to force fresh, outside air into the vehicle.
STARTING AND OPERATING 305
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•Be sure your vehicle is not touching the jump start
vehicle.
•Observe all Battery Warnings in Section 7 of this
manual, while jump starting your vehicle.
WARNING!
Do not attempt to push or tow your vehicle to get it
started. Unburned fuel could enter the catalytic
converter and, once the engine has started, ignite and
damage the converter and vehicle.
EMERGENCY TOW HOOKS—IF EQUIPPED
If your vehicle is equipped with tow hooks, there will be
one in the rear and two mounted on the front of the
vehicle. The rear hook will be located on the driver’s side
of the vehicle.
NOTE:For off-road recovery, it is recommended to use
both of the front tow hooks to minimize the risk of
damage to the vehicle.
CAUTION!
Tow hooks are for emergency use only, to rescue a
vehicle stranded off road. Do not use tow hooks for
tow truck hookup or highway towing. You could
damage your vehicle.
338 WHAT TO DO IN EMERGENCIES

MAINTAINING YOUR VEHICLE
CONTENTS

3.7L Engine...........................344

4.7L Engine...........................345

5.7L Engine...........................346

Onboard Diagnostic System—OBDII........347
▫Loose Fuel Filler Cap Message............347

Emissions Inspection And Maintenance
Programs............................348

Replacement Parts......................349

Dealer Service.........................350
Maintenance Procedures..................350
▫Engine Oil..........................351
▫Drive Belts—Check Condition And
Tensioner...........................354
▫Spark Plugs.........................355
▫Catalytic Converter....................355
▫Crankcase Emission Control System........357
▫Air Cleaner Filter.....................358
▫Maintenance-Free Battery................358
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Belts should be inspected for evidence of cuts, cracks,
glazing, or frayed cords and replaced if there is indication
of damage which could result in belt failure. Low gen-
erator belt tension can cause battery failure.
Also, check belt routing to make sure there is no inter-
ference between the belts and other engine components.
Spark Plugs
Spark plugs must fire properly to assure engine perfor-
mance and emission control. New spark plugs should be
installed at the specified mileage. The entire set should be
replaced if there is any malfunction due to a faulty spark
plug. Refer to the“Vehicle Emission Control Informa-
tion”label in the engine compartment for spark plug
information.
Catalytic Converter
The catalytic converter requires the use of unleaded fuel
only. Leaded gasoline will destroy the effectiveness of the
converter as an emission control device.
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.
MAINTAINING YOUR VEHICLE 355
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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.
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 ex-
haust system. Do not park or operate your vehicle in
areas where your exhaust system can contact any-
thing 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 tune up to manufacturer’s specifica-
tions, should be obtained immediately.
356 MAINTAINING YOUR VEHICLE

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.
•Do not idle the engine for prolonged periods during
very rough idle or malfunctioning operating condi-
tions.
•Do not allow vehicle to run out of fuel.NOTE:Intentional tampering with emissions control
systems can result in civil penalties being assessed
against you.
Crankcase Emission Control System
Proper operation of this system depends on freedom
from sticking or plugging due to deposits. As vehicle
mileage builds up, the PCV valve and passages may
accumulate deposits. If a valve is not working properly,
replace it with a new valve. DO NOT ATTEMPT TO
CLEAN THE OLD PCV VALVE!
Check ventilation hose for indication of damage or
plugging deposits. Replace if necessary.
MAINTAINING YOUR VEHICLE 357
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Auxiliary Electrical Outlet (Power Outlet)...... 162
Auxiliary Power Outlet................... 162
Battery............................... 358
Emergency Starting..................... 336
Keyless Transmitter Replacement (RKE)....... 23
Saving Feature (Protection)............... 122
Belts, Drive............................ 354
Belts, Seat.............................. 32
Body Mechanism Lubrication............... 362
B-Pillar Location........................ 283
Brake Assist System...................... 133
Brake Control System, Electronic............. 131
Brake System........................... 369
Anti-Lock (ABS)....................131,269
Hoses.............................. 370
Master Cylinder....................... 370
Parking............................. 267
Warning Light........................ 180Brake/Transmission Interlock............... 255
Break-In Recommendations, New Vehicle........ 68
Bulb Replacement.....................386,387
Capacities, Fluid........................ 392
Caps, Filler
Fuel................................ 306
Radiator (Coolant Pressure)............... 366
Car Washes............................ 376
Carbon Monoxide Warning............69,153,305
Cargo Area Cover....................... 166
Cargo Area Features...................... 165
Cargo Compartment...................... 165
Light............................... 165
Luggage Carrier....................... 171
Cargo Light............................ 165
Cargo Load Floor........................ 169
Cargo Tie-Downs........................ 167
Catalytic Converter...................... 355
INDEX 425
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