JEEP GRAND CHEROKEE 2007 WK / 3.G Owners Manual

MAINTAINING YOUR VEHICLE
CONTENTS

Engine Compartment – 3.7L...............354

Engine Compartment – 4.7L...............355

Engine Compartment – 5.7L...............356

Engine Compartment – 3.0L Diesel..........357

Onboard Diagnostic System — OBD II........358
▫Loose Fuel Filler Cap Message............358

Emissions Inspection And Maintenance
Programs............................359

Replacement Parts......................361
Dealer Service.........................361

Maintenance Procedures..................362
▫Engine Oil..........................362
▫Drive Belts — Check Condition And Tension . . 366
▫Spark Plugs.........................367
▫Spark Plug Wires.....................367
▫Engine Air Cleaner Filter................367
▫Catalytic Converter....................368
▫Crankcase Emission Control System........369
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▫Maintenance-Free Battery................370
▫Air Conditioner Maintenance.............371
▫Power Steering Fluid Check..............372
▫Body Lubrication.....................374
▫Windshield Wiper Blades................374
▫Windshield Washers — Front And Rear.....374
▫Exhaust System......................375
▫Cooling System.......................376
▫Hoses And Vacuum/Vapor Harnesses.......381
▫Fuel System Connections................382
▫Brake System........................382
▫Front/Rear Axle Fluid..................385
▫Transfer Case........................385▫Automatic Transmission................386
▫Appearance Care And Protection From
Corrosion...........................389

Fuse Panel...........................393
▫Interior Fuses........................393
▫Underhood Fuses (Power Distribution
Center)............................396
▫Underhood Fuses (Integrated Power
Module)............................399

Vehicle Storage........................400

Replacement Bulbs......................401

Bulb Replacement......................402
▫Head Light..........................402
▫Front Turn Signal.....................403
352 MAINTAINING YOUR VEHICLE

▫FrontFogLight ......................404
▫Rear Tail, Stop, Turn Signal, And
Back-Up Lights.......................404
▫Center High Mounted Stop Light (CHMSL) . . . 406

Fluids And Capacities...................407
Fluids, Lubricants, And Genuine Parts........408
▫Engine.............................408
▫Chassis............................409
MAINTAINING YOUR VEHICLE 353
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ENGINE COMPARTMENT – 3.7L
354 MAINTAINING YOUR VEHICLE

ENGINE COMPARTMENT – 4.7L
MAINTAINING YOUR VEHICLE 355
7

ENGINE COMPARTMENT – 5.7L
356 MAINTAINING YOUR VEHICLE

ENGINE COMPARTMENT – 3.0L DIESEL
MAINTAINING YOUR VEHICLE 357
7

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.” 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 dealer for service as soon as
possible.CAUTION!
•Prolonged driving with the “Malfunction Indica-
tor Light” 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 per-
formed.
•If the “Malfunction Indicator Light” is flashing
while the engine is running, severe catalytic con-
verter damage and power loss will soon occur.
Immediate service is required.
Loose Fuel Filler Cap Message
After fuel is added, the vehicle diagnostic system can
determine if the fuel filler cap is loose, improperly
installed, or damaged. A “CHECK GASCAP” message
will be displayed in the EVIC (Refer to Section 4 of this
358 MAINTAINING YOUR VEHICLE

manual). Tighten the gas cap until aclickingsound is
heard. This is an indication that the gas cap is properly
tightened.
This message may be temporarily overridden by pressing
either the C/T, STEP, or MENU buttons. However, after
one minute of no customer interaction, the EVIC will
display again the “CHECK GASCAP” message. The
message will remain displayed until the vehicle diagnos-
tic system can retest the fuel system. The test will
perform the next time the vehicle is started, if the vehicle
was keyed off above 40°F (4°C) outside temperature and
the following vehicle start is above 40°F (4°C) outside
temperature. It may be possible to have a message that
will not clear due to the test being disabled due to low
outside temperatures. If the test is performed and the
problem is gone, the message will disappear.
If the problem persists, the message will appear the next
time the vehicle is started. This might indicate a damagedcap. If the problem is detected twice in a row, the system
will turn on the Malfunction Indicator Light (MIL).
Resolving the problem will turn the MIL light off. See
your authorized dealer for service.
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 which have an I/M (Inspection and
Maintenance) requirement, this check verifies the
following: the MIL (Malfunction Indicator Lamp)
is functioning and is not on when the engine is running,
and that the OBD (On Board Diagnostic) system is ready
for testing.
Normally, the OBD system will be ready. The OBD
system maynotbe ready if your vehicle was recently
serviced, if you recently had a dead battery, or a battery
MAINTAINING YOUR VEHICLE 359
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replacement. If the OBD system should be determined
not ready for the I/M test, your vehicle may fail the test.
Your vehicle has a simple ignition key actuated test
which you can use prior to going to the test station. To
check if your vehicle’s OBD system is ready, you must do
the following:
1. Insert your ignition key into the ignition switch.
2. Turn the ignition to the ON position, but do not crank
or start the engine.
3. If you crank or start the engine, you will have to start
this test over.
4. As soon as you turn your key to the ON position, you
will see your MIL symbol come on as part of a normal
bulb check.
5. Approximately 15 seconds later, one of two things will
happen:a. The MIL will flash for about 10 seconds and then
return to being fully illuminated until you turn off the
ignition key or start the engine. This means that your
vehicle’s OBD system isnot readyand you shouldnot
proceed to the I/M station.
b. The MIL will not flash at all and will remain fully
illuminated until you turn off the ignition key or start
the engine. This means that your vehicle’s OBD system
isreadyand you can proceed to the I/M station.
If your OBD system isnot ready,you should see your
authorized dealer or repair facility. If your vehicle was
recently serviced or had a battery failure or replacement,
you may need to do nothing more than drive your
vehicle as you normally would in order for your OBD
system to update. A recheck with the above test routine
may then indicate that the system is now ready.
Regardless of whether your vehicle’s OBD system is
ready or not ready, if the MIL symbol is illuminated
360 MAINTAINING YOUR VEHICLE