2007 JEEP GRAND CHEROKEE service

Maintenance
If you operate the vehicle using E-85 fuel, follow “Main-
tenance Schedule B.” Refer to Section 8 of this manual.
CAUTION!
Do not use ethanol mixture greater than 85% in your
vehicle. It will cause difficulty in cold starting and
may affect driveability.
FUEL REQUIREMENTS — DIESEL
Diesel fuels are available from most reputable fuel mar-
keters. We encourage you to use only the best quality fuel
with a calculated Cetane Index of 50 or higher. In
addition, the manufacturer recommends using diesel fuel
with a sulfur content ofless than 15 ppm.See your
authorized dealer or distributor for further information
regarding fuels available in your area.In areas where diesel fuel is below the recommended
quality levels (high levels of sulfur and water) it is critical
to monitor the fuel filter for contamination and the
“Water-In-Fuel” message in the EVIC (Refer to Section 4).
Failure to properly service the fuel system for these items
can significantly reduce engine life and lead to major
engine repair. More frequent service intervals of the fuel
filter/water separator unit may be required under these
conditions than those shown in “Maintenance Schedule
A or B.” See your authorized dealer or distributor for
specific information.
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removes this heat. You can also turn the Temperature
Control to maximum heat, the Mode Control to floor, and
the Fan Control to High. This allows the heater core to act
as a supplement to the radiator and aids in removing heat
from the engine cooling system.
CAUTION!
Driving with a hot cooling system could damage
your vehicle. If the temperature gauge reads “H”,
pull over and stop the vehicle. Idle the vehicle with
the air conditioner turned off until the pointer drops
back into the normal range. If the pointer remains on
the “H”, and you hear continuous chimes, turn the
engine off immediately, and call for service.
JACKING AND TIRE CHANGING
WARNING!
•Getting under a jacked-up vehicle is dangerous.
The vehicle could slip off the jack and fall on you.
You could be crushed. Never get any part of your
body under a vehicle that is on a jack. If you need
to get under a raised vehicle, take it to a service
center where it can be raised on a lift.
•The jack is designed to use as a tool for changing
tires only. The jack should not be used to lift the
vehicle for service purposes. The vehicle should
be jacked on a firm level surface only. Avoid ice or
slippery areas.
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nuts until each nut has been tightened twice. Correct
wheel nut tightness is 130 N·m (95 ft. lbs). If in doubt
about the correct tightness, have them checked with a
torque wrench by your authorized dealer or at a service
station.
10. Lower the jack to it’s fully closed position.
WARNING!
A loose tire or jack, thrown forward in a collision or
hard stop could endanger the occupants of the ve-
hicle. Always stow the jack parts and the spare tire in
the places provided.
11. Secure the tire, jack, and tools in their proper loca-
tions.NOTE:Tire should be stowed with the “beauty” side
up. Storing the tire upside down may result in scratching
or damage to the wheel face. Continue winching up the
tire until you hear the winch “ratchet” three times.
Double check to ensure the tire is snug against the
underbody of the vehicle. Damage to the winch cable
may result if the vehicle is driven with the tire loose.
WARNING!
Do not use power tools to winch the tire up or down.
Impact type tools may damage the winch mecha-
nism.
12. Reinstall the plastic plug into the floor of the cargo
area.
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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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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

during normal vehicle operation, you should have your
vehicle serviced before going to the I/M station. The I/M
station can fail your vehicle because the MIL symbol is on
with the engine running.
REPLACEMENT PARTS
Use of genuine Moparparts for normal/scheduled
maintenance and repairs is highly recommended to in-
sure the designed performance. Damage or failures
caused by the use of non-Moparparts for maintenance
and repairs will not be covered by the manufacturer’s
warranty.
DEALER SERVICE
Your dealer has the qualified service personnel, special
tools and equipment to perform all service operations in
an expert manner. Service Manuals are available which
include detailed service information for your vehicle.
Refer to these manuals before attempting any procedure
yourself.NOTE:Intentional tampering with emissions control
systems can result in civil penalties being assessed
against you.
WARNING!
You can be badly injured working on or around a
motor vehicle. Do only that service work for which
you have the knowledge and the proper equipment.
If you have any doubt about your ability to perform
a service job, take your vehicle to a competent
mechanic.
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