service DODGE CARAVAN 2004 4.G Service Manual

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!
Prolonged driving with the ªMalfunction Indicator
Lightº on could cause further damage to the emis-
sion control system. It could also affect fuel economy
and driveability. The vehicle must be serviced before
any emissions tests can be performed.
If the ªMalfunction Indicator Lightº is flashing
while the engine is running, severe catalytic con-
verter damage and power loss will soon occur. Im-
mediate service is required.
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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 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
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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
during normal vehicle operation, you should have yourvehicle 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.
302 MAINTAINING YOUR VEHICLE

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.
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 engine lubrication, the engine oil must
be maintained at the correct level. Check the oil level at
regular intervals, such as every fuel stop.
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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).
²Stop and Go driving.
²Extensive engine idling.
²Driving in dusty conditions.
²Short trips of less than 10 miles (16 km).
²More than 50% of your driving is at sustained high
speeds during hot weather, above 90ÉF (32ÉC).
²Trailer towing.
²Taxi, Police or delivery service (commercial service).
²Off-Road or desert operation.IfANYof these apply to you, then change your engine oil
at every interval shown in schedule ªBº of the ªMainte-
nance Schedulesº section of this manual.
If none of these apply to you, then change your engine oil
at every interval shown on schedule ªAº of the ªMain-
tenance Schedulesº section of this manual
NOTE:Under no circumstances should oil change in-
tervals exceed 6000 miles (10 000 km) or 6 months
whichever comes first.
Engine Oil Selection
For best performance and maximum protection under all
types of operating conditions, the manufacture only
recommends engine oils that are API certified and meet
the requirements of DaimlerChrysler Material Standard
MS-6395. Use Mopar or an equivalent oil meeting the
specification MS-6395.
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Synthetic Engine Oils
There are a number of engine oils being promoted as
either synthetic or semi-synthetic. If you chose to use
such a product, useonlythose oils that meet the Ameri-
can Petroleum Institute (API) and SAE viscosity stan-
dard. Follow the service schedule that describes your
driving type.
Materials Added to Engine Oil
The manufacture strongly recommends against the addi-
tion of any additives (other than leak detection dyes) to
the engine oil. Engine oil is an engineered product and
it's performance may be impaired by supplemental ad-
ditives.
Disposing of Used Engine Oil And Oil Filters
Care should be taken in disposing of used engine oil and
oil filters from your vehicle. Used oil and oil filters,
indiscriminately discarded, can present a problem to the
environment. Contact your dealer, service station, orgovernmental agency for advice on how and where used
oil and oil filters can be safely discarded in your area.
Engine Oil Filter
The engine oil filter should be replaced at every engine
oil change.
Engine Oil Filter Selection
All the manufacturers 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 Tension
At the mileage indicated in the maintenance schedule, all
belts should be checked for condition and proper tension.
Improper belt tension can cause belt slippage and failure.
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Belts should be inspected for evidence of cuts, cracks, or
glazing, and replaced if there is indication of damage
which could result in belt failure. If adjustment is re-
quired, the belts must be adjusted according to the
specifications and procedures described in the Service
Manual. Low generator belt tension can cause battery
failure. A special tool is required to properly measure
tension and to restore belt tension to factory specifica-
tions.
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 sparkplug, 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.
Engine Air Cleaner Filter
Under normal driving conditions, replace the air filter at
the intervals shown on Schedule ªAº. If, however, you
drive the vehicle frequently under dusty or severe con-
ditions, the filter element should be inspected periodi-
cally and replaced if necessary at the intervals shown on
Schedule ªBº.
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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 the
vehicle.
NOTE:Intentional tampering with emissions control
systems can result in civil penalties being assessed
against you.
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 indicate severe
and abnormal catalyst overheating. If this occurs, the
vehicle should be stopped, the engine shut off and the
vehicle allowed to cool. Thereafter, service, including a
tune-up to manufacturer's specifications, should be ob-
tained immediately.
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CAUTION!
²It is essential when replacing the cables on the
battery that the positive cable is attached to the
positive post and the negative cable is attached to
the negative post. Battery posts are marked posi-
tive (+) and negative (-) and identified on the
battery case. Cable clamps should be tight on the
terminal posts and free of corrosion.
²If a ªfast chargerº is used while battery is in
vehicle, disconnect both vehicle battery cables
before connecting the charger to battery. Do not
use a ªfast chargerº to provide starting voltage.
Air Conditioner
For best possible performance, your air conditioner
should be checked and serviced by an Authorized Dealer
at the start of each warm season. This service should
include cleaning of the condenser fins and a system
performance check. Drive belt tension should also be
checked at this time.
312 MAINTAINING YOUR VEHICLE

WARNING!
²Use only refrigerants approved by this manufac-
turer for your air conditioning system. Some un-
approved refrigerants are flammable and can ex-
plode, injuring you. Other unapproved
refrigerants can cause the system to fail, requiring
costly repairs.
²Never add air conditioning refrigerant to correct a
non-cooling problem unless pressure gauges are
connected to the system by a certified technician.
Lack of cooling could be due to a restriction and
adding refrigerant may cause a dangerous pres-
sure rise and you could be injured.
Refrigerant Recovery And Recycling
The air conditioning system of your vehicle contains
R-134a, a refrigerant that does not deplete the ozone layer
in the upper atmosphere. The manufacturer recommendsthat air conditioning service be done by facilities using
refrigerant recycling and recovery equipment that meets
SAE standard J1991.
A/C Air Filter
The filter access door is located under the instrument
panel on the passenger side. To replace the filter slide the
lock toward the rear of the vehicle (unlock position).
Remove the access door and pull the filter downward.
When installing a new filter, ensure its proper orienta-
tion. Align the black arrow on the bottom of the filter
frame with the direction of airflow (away from the
blower motor and towards the center of the car).
Refer to the ªMaintenance Schedulesº section of this
manual for the recommended air conditioning filter
replacement intervals.
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