2007 JEEP GRAND CHEROKEE check engine

Towing Tips
Before setting out on a trip, practice turning, stopping
and backing the trailer in an area away from heavy
traffic.
Towing Tips Ð Automatic Transmission
The ªDº range can be selected when towing. However, if
frequent shifting occurs while in this range, the ª3º range
should be selected.
NOTE:Using the ª3º range while operating the vehicle
under heavy operating conditions will improve perfor-
mance and extend transmission life by reducing exces-
sive shifting and heat build up. This action will also
provide better engine braking.
The automatic transmission fluid and filter should be
changed if you REGULARLY tow a trailer for more than
45 minutes of continuous operation. See Schedule ªBº in
section 8 of this manual for transmission fluid change
intervals.
NOTE:Check the automatic transmission fluid level
before towing.
7- Pin Connector
288 STARTING AND OPERATING

MAINTAINING YOUR VEHICLE
CONTENTS
mEngine Compartment ± 6.1L...............300
mOnboard Diagnostic System Ð OBD II........301
NLoose Fuel Filler Cap Message............302
mEmissions Inspection And Maintenance
Programs............................302
mReplacement Parts......................304
mDealer Service.........................304
mMaintenance Procedures..................305
NEngine Oil..........................305NEngine Oil Filter......................308
NDrive Belts Ð Check Condition And
Tensioner...........................309
NSpark Plugs.........................309
NEngine Air Cleaner Filter................310
NFuel Filter..........................310
NCatalytic Converter....................310
NMaintenance-Free Battery................312
NAir Conditioner Maintenance.............313
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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
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,
MAINTAINING YOUR VEHICLE 303
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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
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 Mopartparts for normal/scheduled
maintenance and repairs is highly recommended to in-
sure the designed performance. Damage or failures
caused by the use of non-Mopartparts 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.
304 MAINTAINING YOUR VEHICLE

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.
MAINTENANCE PROCEDURES
The pages that follow contain therequiredmaintenance
services determined by the engineers who designed your
vehicle.
Besides the maintenance items for which there are fixed
maintenance intervals, there are other items that should
operate satisfactorily without periodic maintenance.
However, if a malfunction of these items does occur, itcould adversely affect the engine or vehicle performance.
These items should be inspected if a malfunction is
observed or suspected.
Engine Oil
Checking Oil Level
To assure proper engine lubrication, the engine oil must
be maintained at the correct level. Check the oil level at
regular intervals, such as every fuel stop.
The best time to check the engine oil level is about 5
minutes after a fully warmed engine is shut off or before
starting the engine after it has sat overnight.
Checking the oil while the vehicle is on level ground will
improve the accuracy of the oil level readings. Maintain
the oil level in the ªSAFEº range. Adding one quart of oil
when the reading is at the bottom of the ªSAFEº range
will result in an oil level at the top of the ªSAFEº range
on these engines.
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NOTE:Fill engine oil one quart at a time.CAUTION!
Overfilling or underfilling will cause oil aeration or
loss of oil pressure. This could damage your engine.
CAUTION!
Operating the engine with the oil levels below the
safe zone, or operating with oil levels that exceed the
top of the safe zone may cause engine damage.
Change Engine Oil
Road conditions and your kind of driving affects the
interval at which your oil should be changed. Check the
following list to see if any apply to you.
²Day or night temperatures are below 32ÉF (0ÉC).
Engine Oil Dipstick
306 MAINTAINING YOUR VEHICLE

Engine Oil Filter Selection
The manufacturer's engines have a full-flow type oil
filter. Use a filter of this type for replacement. The quality
of replacement filters varies considerably. Only high
quality filters should be used to assure most efficient
service. Mopar Engine Oil Filters are a high quality oil
filter and are recommended.
Drive Belts Ð Check Condition and Tensioner
Belt tension is controlled by means of an automatic
tensioner. No belt tension adjustments are required.
However, belt and belt tensioner condition should be
inspected at the specified intervals, and replaced if re-
quired. See your authorized dealer for service.
At the mileage indicated on the appropriate ªMainte-
nance Schedule,º all belts and tensioner should be
checked for condition. Improper belt tension can cause
belt slippage and failure.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 interfer-
ence between the belts and other engine components.
Spark Plugs
Spark plugs must fire properly to assure engine perfor-
mance and emission control. New plugs should be in-
stalled at the specified mileage. The entire set should be
replaced if there is any malfunction due to a faulty spark
plug. Malfunctioning spark plugs can damage the cata-
lytic converter. For proper type of replacement spark
plugs, refer to the ªVehicle Emission Control Informa-
tionº label in the engine compartment.
MAINTAINING YOUR VEHICLE 309
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CAUTION!
Do not use Automatic Transmission Fluid (ATF) or
other types of power steering fluids when servicing
the power steering system of this vehicle. Damage to
the power steering system can result from the use of
the wrong power steering fluid.
Checking the power steering fluid level at a defined
service interval is not required. The fluid should only be
checked if a leak is suspected, abnormal noises are
apparent, and/or the system is not functioning as antici-
pated. Coordinate inspection efforts through a certified
ªDaimlerChrysler Dealership.º
WARNING!
Fluid level should be checked on a level surface with
the engine off to prevent injury from moving parts,
and to insure accurate fluid level reading. Do not
overfill. Use only the manufacturer's recommended
fluid.
If necessary, add fluid to restore to the proper indicated
level. With a clean cloth, wipe any spilled fluid from all
surfaces. Refer to Fluids, Lubricants, and Genuine Parts
for correct fluid type.
NOTE:Upon initial start-up in cold weather, the power
steering pump may make noise for a short period of time.
This is due to the cold, thick fluid in the steering system.
This noise should be considered normal, and does not in
any way damage the steering system.
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