2005 JEEP GRAND CHEROKEE catalytic converter

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 313 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.
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.
UNDERSTANDING YOUR INSTRUMENT PANEL 165
4

•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.
280 STARTING AND OPERATING

when attaching clamps. If acid splashes in eyes or on
skin, flush the area immediately with large amounts of
water.
•Do not use a booster battery or any other booster
source that has a greater than 12–volt system, i.e., do
not use a 24–volt power source.
•Never attempt to jump start a discharged battery that
is frozen, because it could rupture or explode during
jump starting.
•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.
WHAT TO DO IN EMERGENCIES 305
6

MAINTAINING YOUR VEHICLE
CONTENTS

3.7L Engine...........................310

4.7L Engine...........................311

5.7L Engine...........................312

Onboard Diagnostic System — OBD II........313
▫Loose Fuel Filler Cap Message............313

Emissions Inspection And Maintenance
Programs............................314

Replacement Parts......................315

Dealer Service.........................316
Maintenance Procedures..................316
▫Engine Oil..........................316
▫Drive Belts - Check Condition And Tension . . . 320
▫Spark Plugs.........................321
▫Catalytic Converter....................321
▫Ignition Cables.......................323
▫Crankcase Emission Control System........323
▫Fuel Filter..........................323
▫Air Cleaner Filter.....................323
7

Special tools are required to properly measure tension
and to restore belt tension to factory specifications. Also,
check belt routing to make sure there is no interference
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.
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.
MAINTAINING YOUR VEHICLE 321
7

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.
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.
322 MAINTAINING YOUR VEHICLE

Catalytic Converter...................... 321
Caution, Exhaust Gas..................... 140
CD Player..........................186,200
Cellular Phone.......................... 76
Center High Mounted Stop Light............ 356
Chains, Tire............................ 275
Changing A Flat Tire..................... 298
Chart, Tire Sizing........................ 256
Checks, Safety........................... 65
Child Restraint....................53,54,59,61
Child Restraint Tether Anchors.............58,59
Child Safety Locks........................ 16
Climate Control......................... 213
Clock................................ 188
Compact Disc Maintenance................. 212
Compass...........................178,182
Compass Calibration..................... 182
Compass Variance....................... 183
Computer, Trip/Travel.................... 178Console, Overhead....................... 137
Contract, Service........................ 386
Converter, Catalytic...................... 321
Cooling System......................... 329
Adding Coolant (Antifreeze).............. 331
Coolant Capacity...................... 357
Coolant Level......................... 332
Disposal of Used Coolant................ 332
Drain, Flush, and Refill.................. 330
Inspection........................... 329
Points to Remember.................... 333
Pressure Cap......................... 331
Radiator Cap......................... 331
Selection of Coolant..................330,357
Crankcase Emission Control System.......... 323
Cruise Control (Speed Control).............. 134
Cruise Light........................... 169
Cup Holder............................ 149
Customer Assistance..................... 384
394 INDEX