2008 DODGE DURANGO Owners Manual

ENGINE COMPARTMENT 4.7L V-8
MAINTAINING YOUR VEHICLE 385
7

ENGINE COMPARTMENT 5.7L HEMI V-8
386 MAINTAINING YOUR VEHICLE

ONBOARD DIAGNOSTIC SYSTEM Ð 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 ªMalfunction Indicator Light.º 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!
²Prolonged driving with the ªMalfunction Indica-
tor Lightº 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.
²If the ªMalfunction Indicator Lightº is flashing
while the engine is running, severe catalytic con-
verter damage and power loss will soon occur.
Immediate service is required.
MAINTAINING YOUR VEHICLE 387
7

Loose Fuel Filler Cap Message
After fuel is added, the vehicle diagnostic system can
determine if the fuel filler cap is possibly loose, improp-
erly installed, or damaged. A loose fuel filler cap message
will be displayed in the instrument cluster. Tighten the
gas cap until a9clicking9sound is heard. This is an
indication that the gas cap is properly tightened. Press
the odometer reset button to turn the message off. If the
problem persists, the message will appear the next time
the vehicle is started. This might indicate a damaged cap.
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.
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
replacement. If the OBD system is determined not ready
for the I/M test, your vehicle may fail the test.
388 MAINTAINING YOUR VEHICLE

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. If you crank or start the engine, you
will have to start this test over.
3. 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.
4. Approximately 15 seconds later, one of two things will
happen:
a. The MIL light will blink for approximately 5 sec-
onds and then remain on until the first engine crank orthe key is turned off. This means that your vehicle's
OBD system isnot readyand you shouldnotproceed
to the I/M station.
b. The MIL light will remain fully illuminated until the
first engine crank or the key is turned off. This means
that your vehicle's OBD system isreadyand you can
proceed to the I/M station.
If your OBD system isnot readyyou should see your
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
during normal vehicle operation, you should have your
MAINTAINING YOUR VEHICLE 389
7

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.
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.
390 MAINTAINING YOUR VEHICLE

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, it
could 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 lubrication of your vehicle's engine, the
engine oil must be maintained at the correct level. The
best time to check the engine oil level is about 5 minutes
after a fully warmed up 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. Always
maintain the oil level within the SAFE zone on the
dipstick. Adding one quart of oil when the reading is at
the bottom of the SAFE zone will result in a reading at the
top of the safe zone on these engines.
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CAUTION!
Overfilling or underfilling the crankcase will cause
oil aeration or loss of oil pressure. This could damage
your engine.
Change Engine Oil
Follow the Maintenance Schedule for recommended en-
gine oil and filter change intervals.
NOTE:Under no circumstances should oil change in-
tervals exceed 6,000 miles (10 000 km) or 6 months
whichever comes first.
4x4 Models, If Used Primarily For Off-Road Operation
Every 50 hours of use.
Dusty Conditions
Driving through dust-laden air increases the problems of
keeping abrasive materials out of the engine. Under these
conditions, special attention should be given to the
engine air cleaner and the crankcase inlet air cleaner. The
crankcase ventilation system should also be checked
periodically. Make sure that these units are always clean.
This will tend to reduce to a minimum the amount of
abrasive material that may enter the engine.
392 MAINTAINING YOUR VEHICLE