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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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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
Page 401 of 532

Engine Oil Selection (Gas Engines)
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.
American Petroleum Institute (API) Engine Oil
Identification Symbol
This symbol means that the oil has
been certified by the American
Petroleum Institute (API). The
manufacture only recommends
API Certified engine oils. Engine Oil Viscosity (SAE Grade)
For trucks with a 5.7L engine operating under a gross
combined weight rating of 14,000 lbs or greater, SAE
5W-30 engine oil is recommended for all operating
temperatures. For all other trucks with a 5.7L engine,
operating under a gross weight rating less than 14,000
lbs SAE 5W-20 engine oil is recommended for all
operating temperatures. These engine oils improve low
temperature starting and vehicle fuel economy. Your
engine oil filler cap also shows the recommended
engine oil viscosity for your vehicle.
For information on engine oil filler cap location, see the
Engine Compartment illustration in this section.
Lubricants which do not have both, the engine oil certi-
fication mark and the correct SAE viscosity grade num-
ber should not be used. MAINTAINING YOUR VEHICLE 401
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Use a container that can hold at least 12 quarts (11.3
Liters) to hold the used oil.
Always check the condition of the used oil. This can give
you an indication of some engine problems that might
exist.
• Thin, black oil indicates fuel dilution.
• Milky discoloration indicates coolant dilution.
Clean the area around the oil filter base. Remove the filter
from the underside of the vehicle using a cap style oil
filter wrench.
Clean the gasket surface of the filter mount. The filter
gasket can stick on the filter mount. Make sure it is
removed.
Change the engine oil filter with every engine oil change.
Only a high quality MOPAR filter should be used to
assure most efficient service. CAUTION!The filtering medium of other aftermarket filters
may disintegrate. Debris from failed filters may plug
the piston oil cooling nozzles, resulting in scuffed
pistons and engine failure.
CAUTION!Fill the oil filter element with clean oil before
installation. Use the same type oil that will be used
in the engine. When filling the oil filter, prevent
foreign material from falling into the filter. Severe
engine damage may occur.
Apply a light film of lubricating oil to the sealing surface
of the filter gasket before installing the filter.404 MAINTAINING YOUR VEHICLE
Page 410 of 532
Draining Fuel/Water Separator Filter (Diesel
Engines)
CAUTION!Do not drain the fuel/water separator filter when the
engine is running. CAUTION!Do not prefill the fuel filter when installing a new
fuel filter. There is a possibility debris could be
introduced into the fuel filter during this action. It is
best to install the filter dry and allow the in-tank lift
pump to prime the fuel system.
NOTE: Care should be taken in disposing of used fluids
from your vehicle. Used fluids, indiscriminately dis-
carded, can present a problem to the environment. Con-
tact your local dealer, service station, or government
agency for advice on recycling programs and for where
used fluids and filters can be properly disposed of in
your area.
Drain a small amount from the fuel/water separator
filter monthly or when the WATER IN FUEL indicator
lamp is on. Turn the drain valve, located on the bottom of410 MAINTAINING YOUR VEHICLE
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the filter, counterclockwise and allow any accumulated
water to drain. Leave the drain valve open until all water
and contaminants have been removed. Close the drain
valve, by turning it clockwise, when clean fuel is visible.
NOTE: The Fuel / Water separator drain valve is
located on the bottom of the fuel filter housing.
If more than a couple ounces of fuel has been drained,
follow the directions below for “Priming if the engine has
run out of fuel.”
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. Priming if the engine has run out of fuel
1. Add a substantial quantity of fuel to the tank 5 to 10
gallons (19L to 38L).
2. Crank the engine for 1 to 2 seconds. If the engine does
not start, then release the key or starter button back to the
RUN position (do not turn the key back to the OFF
position). The electric fuel transfer pump will continue to
run and purge air from the system for about 25 seconds.
After 25 seconds, attempt to start the engine again.
3. Start the engine using the Normal Starting Procedure.
4. Repeat the procedure if the engine does not start. MAINTAINING YOUR VEHICLE 411
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CAUTION!Do not engage the starter motor for more than 15
seconds at a time. Allow two minutes between the
cranking intervals.
NOTE: The engine may run rough until the air is forced
from all the fuel lines.
CAUTION!Diesel fuel will damage black top paving surfaces.
Drain the filter into an appropriate container. WARNING!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.
CAUTION!Due to lack of lubricants in alcohol or gasoline, the
use of these fuels can cause damage to the fuel
system.
NOTE: A maximum blend of 5% biodiesel, meeting
ASTM specification D-6751 may be used with your
Cummins Diesel equipped vehicle. Use of bio-diesel412 MAINTAINING YOUR VEHICLE