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ENGINE COMPARTMENT— 5.7L GAS ENGINE MAINTAINING YOUR VEHICLE 393
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ONBOARD DIAGNOSTIC SYSTEM (OBD II)
Vehicles equipped with California emissions controls
have a sophisticated onboard diagnostic system called
OBDII. 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 emissions 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 driveable and not
need towing, see your dealer for service as soon as
possible. CAUTION!Prolonged driving with the “Malfunction Indicator
Light” 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 “Malfunction Indicator Light” is flashing,
severe catalytic converter damage and power loss
will soon occur. Immediate service is required.
Loose Fuel Filler Cap Message
If the vehicles diagnostic system determines that the fuel
filler cap in loose, improperly installed, or damaged, a
GASCAP message will be displayed in the instrument
cluster. Tighten the gas cap until a “clicking” sound is
heard. This is an indication that the gas cap is properly
tightened. Press the odometer reset button to turn the394 MAINTAINING YOUR VEHICLE
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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.
REPLACEMENT PARTS
Use of genuine Mopar parts for normal/scheduled
maintenance and repairs is highly recommended to in-
sure the designed performance. Damage or failures
caused by the use of non-Mopar parts for maintenance
and repairs will not be covered by the manufacturer’s
warranty. ENGINE DATA PLATE
Use the information from the engine data plate when
discussing service or sourcing parts for your engine. The
engine data plate is located on the intake side of the
breather cover.
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. MAINTAINING YOUR VEHICLE 395
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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.
SERVICE INFORMATION
Mopar Fluids, Lubricants and Parts are available from
your dealer and will help you keep your vehicle operat-
ing at its best. Your dealer also 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 attempt-
ing any procedure yourself. See Service Publications
information at the back of this manual. CAUTION!To maintain your vehicle safely follow these guide-
lines:
• Watch your vehicle’s mileage and check your Mainte-
nance Schedules regularly for required servicing. Ex-
cessive wear or damage to certain vehicle components
can result if required services are not performed.
• If you have your vehicle undercoated, inspect for
undercoating material on the propeller shafts. Such
material could cause the shafts to become unbalanced
and result in drivetrain vibrations. Remove any under-
coating with solvent.
• If you have your vehicle undercoated, make sure no
undercoating material is sprayed on the exhaust sys-
tem or components of the seat belt system.396 MAINTAINING YOUR VEHICLE
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NOTE: It is not possible for the manufacturer and
Cummins, Inc. to anticipate every possible circumstance
that can involve a potential hazard.
WARNING!To maintain your vehicle safely and avoid personal
injury, follow these guidelines:
• Never spray or pour diesel fuel, flammable liquid or
starting fluids (ether) into the air cleaner assembly, air
intake piping or turbocharger inlet in an attempt to
start the vehicle, unintended engine acceleration may
occur.
• Do not use alcohol or gasoline as a fuel blending agent.
They can be unstable under certain conditions and be
hazardous or explosive when mixed with diesel fuel. • If an engine has been operating and the coolant is hot,
allow the engine to cool before you slowly loosen the
filler cap and relieve the pressure from the cooling
system.
• To avoid burns, remember that the engine components
will stay hot after the engine is shut off.
• Do not use gasoline or other flammable materials to
clean parts. Always use approved cleaning solvents.
• Relieve all pressure in the fuel, oil and cooling systems
before any lines, fittings or related items are removed
or disconnected. Be alert for possible pressure when
disconnecting any device from a system that utilizes
pressure. Do not check for pressure leaks with your
hand. High pressure oil or fuel can cause personal
injury. MAINTAINING YOUR VEHICLE 397
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WARNING!Do not open the high pressure fuel system with the
engine running. Engine operation causes high fuel
pressure. High pressure fuel spray can cause serious
injury or death.
• Important: All maintenance other than that listed in
this manual, as well as some procedures listed here,
MUST be performed by your local Dodge Truck
Dealer. Your authorized Dodge Dealer has been
trained and has the necessary parts to maintain your
engine. MAINTENANCE PROCEDURES
The pages that follow contain the required maintenance
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. Check
the oil level at regular intervals. The best time to check
the oil level is before starting the engine after it has been
parked overnight. When checking oil after operating the398 MAINTAINING YOUR VEHICLE
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engine, first ensure the engine is at full operating tem-
perature, then wait at least 15 minutes after engine
shutdown to check the oil.
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.
CAUTION!Overfilling or underfilling the crankcase will cause
oil aeration or loss of oil pressure. This could dam-
age your engine. Never operate the engine with oil level below the “ADD”
mark or above the upper “SAFE” mark. MAINTAINING YOUR VEHICLE 399
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Change Engine Oil (Gas Engines)
Road conditions as well as your kind of driving affect the
interval at which your oil should be changed. Check the
following to determine if any apply to you:
• Frequent short trips where the engine does not achieve
full operating temperature (operating temperature de-
fined as 190° F (66° C ) coolant temperature).
• Extensive engine idling (over 10 minutes per hour of
operation) at ambient temperatures less than 32° F (0°
C).
• Driving in dusty conditions.
• Frequent trailer towing.
• Taxi, police, or delivery service (commercial service).
• Off-road or desert operation.
• Extensive operation at high engine speeds (greater
than 2900 rpm) and loads (greater than 70% throttle). If ANY of these apply to you, then change your engine oil
at every interval shown in schedule B of the Mainte-
nance Schedules section of this manual.
If none of these apply to you, then change your engine oil
at every interval shown on schedule A of the Mainte-
nance Schedules section of this manual.
NOTE: Most vehicles are operated under the conditions
listed for Schedule B.
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, the crankcase inlet air cleaner and the
crankcase ventilation system. Make sure that these units
are clean at all times. This will tend to reduce to a
minimum the amount of abrasive material that may enter
the engine.400 MAINTAINING YOUR VEHICLE