Page 409 of 527
mVehicle Storage........................464
mReplacement Light Bulbs.................465
mBulb Replacement......................466
NHeadlight (Halogen)/Front Park And Turn
Lights.............................466
NFog Lights..........................469
NTail, Stop, Turn And Backup Lights.........470
NCenter High-Mounted Stoplight (CHMSL)
With Cargo Light.....................473
NCab Top Clearance Lights Ð If Equipped....474NTailgate ID Lights (Dual Rear Wheels) Ð If
Equipped...........................476
NRear Light Bar ID Marker (Dual Rear Wheel) Ð
If Equipped.........................477
NSide Marker Lights (Dual Rear Wheels)......478
mFluid Capacities........................479
mFluids, Lubricants And Genuine Parts........480
NEngine.............................480
NChassis............................482
MAINTAINING YOUR VEHICLE 407
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        Page 411 of 527

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 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 driveable 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 emission
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,
severe catalytic converter damage and power loss
will soon occur. Immediate service is required.
REPLACEMENT PARTS
Use of genuine Mopartparts for normal/scheduled
maintenance and repairs is highly recommended to en-
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.
MAINTAINING YOUR VEHICLE 409
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        Page 419 of 527

CAUTION!
Fill the oil filter element with clean oil before instal-
lation. 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.
CAUTION!
Overtightening may distort the threads or damage
the filter element seal.Install the filter as specified by the filter manufacturer.
Turn the filter 3/4 to one full turn after making contact
with the gasket.
Check the condition of the threads and sealing surface on
the oil pan and drain plug.
Install the drain plug and sealing washer and tighten to
37 ft-lbs. (50 N´m).
Use only high-quality multi-grade lubricating oil in your
CumminstDiesel Engine. Choose the correct oil for your
operating conditions as outlined in the Selection of
Engine Oil.
CumminstTurbo Diesel
Fill the engine with the correct grade of new oil. The
engine capacity is 11 quarts (10.4 liters) in the crankcase
and 1 quart (.95 liter) in the lubricating oil filter.
MAINTAINING YOUR VEHICLE 417
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        Page 424 of 527
Draining Fuel/Water Separator Filter (6.7L Diesel
Engine)
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 that 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:The fuel filter and water separator assembly is
located on the driver's side of the engine. The best access
to the water drain valve is through the driver's side
wheel well.
NOTE:If water is detected in the water separator while
the engine is running or while the key is in the on
position, the WATER IN FUEL LIGHT will illuminate
and an audible chime will be heard five times. At this
point you should stop the engine and drain the water
from the separator.
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        Page 425 of 527

If the WATER IN FUEL LIGHT comes on and a single
chime is heard while you are driving, or with the key in
the ON position, there may be a problem with your water
separator wiring or sensor. See your authorized dealer
for service.
Upon proper draining of the water from the fuel filter, the
WATER IN FUEL LIGHT will remain illuminated for
approximately 10 seconds. If the water was drained
while the engine was running, the water in fuel light may
remain on for approximately three minutes.
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 authorized 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 LIGHT is
on. Turn the drain valve located on the bottom of the
filter counterclockwise and allow any accumulated water
to drain into an approved container. 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 ªPriming if the engine has
run out of fuel.º
MAINTAINING YOUR VEHICLE 423
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        Page 430 of 527

CATALYST FULL SERVICE REQD
If the particulate filter reaches 99% of its capacity, the
overhead console in your vehicle will chime twice and
display the message CATALYST FULL SERVICE REQD.
At this point the engine PCM will register a fault code,
the instrument panel will display a MIL light and the
engine PCM will derate the truck, reducing its horse-
power and torque output.
The PCM derates the engine in order to limit the likeli-
hood of permanent damage to the aftertreatment system.
If this condition is not corrected and a dealer service is
not performed, extensive exhaust aftertreatment damage
can occur. In order to correct this condition it will be
necessary to have the truck serviced by your local
authorized dealer.
Maintenance Free Batteries
The top of the maintenance free batteries are perma-
nently sealed. You will never have to add water, nor is
periodic maintenance required.
NOTE:Replacement batteries should both be of equal
capacity to prevent damage to the vehicle's charging
system.
428 MAINTAINING YOUR VEHICLE 
     
        
        Page 436 of 527

Windshield Washers
The fluid reservoir is located under the hood and should
be checked for fluid level at regular intervals. Fill the
reservoir with windshield washer solvent only (not ra-
diator antifreeze). When refilling the washer fluid reser-
voir, take some washer fluid and apply it to a cloth or
towel and wipe the wiper blades clean. This will help
blade performance.
To prevent freeze-up of your windshield washer system
in cold weather, select a solution or mixture that meets or
exceeds the temperature range of your climate. This
rating information can be found on most washer fluid
containers.
The washer fluid reservoir will hold a full gallon of fluid
when the Low Washer Fluid Light illuminates.WARNING!
Commercially available windshield washer solvents
are flammable. They could ignite and burn you. Care
must be exercised when filling or working around
the washer solution.
After the engine has warmed, operate the defroster for a
few minutes to reduce the possibility of smearing or
freezing the fluid on the cold windshield. MopartAll
Weather Windshield Washer Solution, used with water as
directed on the container, aids cleaning action, reduces
the freezing point to avoid line clogging, and is not
harmful to paint or trim.
434 MAINTAINING YOUR VEHICLE 
     
        
        Page 451 of 527

5. Remove the dipstick, wipe it clean and reinsert it until
seated.
6. Remove the dipstick again and note the fluid level on
both sides. The fluid level should be between the ªHOTº
(upper) reference holes on the dipstick at normal operat-
ing temperature. Verify that a solid coating of oil is seen
on both sides of the dipstick. If the fluid is low, add as
required into the dipstick tube.Do not overfill.After
adding any quantity of oil through the oil fill tube, wait
a minimum of two minutes for the oil to fully drain into
the transmission before rechecking the fluid level.
NOTE:If it is necessary to check the transmissionbelow
the operating temperature, the fluid level should be
between the two ªCOLDº (lower) holes on the dipstick
with the fluid at approximately 70ÉF (21ÉC) (room tem-
perature). If the fluid level is correctly established at
room temperature, it should be between the ªHOTº(upper) reference holes when the transmission reaches
180ÉF (82ÉC). Remember it is best to check the level at the
normal operating temperature.
CAUTION!
Be aware that if the fluid temperature is below 50ÉF
(10ÉC) it may not register on the dipstick. Do not add
fluid until the temperature is elevated enough to
produce an accurate reading.
7. Check for leaks. Release parking brake.
To prevent dirt and water from entering the transmission
after checking or replenishing fluid, make certain that the
dipstick cap is properly reseated. It is normal for the
dipstick cap to spring back slightly from its fully seated
position, as long as its seal remains engaged in the
dipstick tube.
MAINTAINING YOUR VEHICLE 449
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