2003 FORD SUPER DUTY instrument cluster

DIESEL ENGINE INFORMATION
The Diesel engine fuel system consists of:
•an engine-mounted secondary fuel filter
•frame-mounted Horizontal Fuel Conditioner Module (HFCM)
•a unit injector for each cylinder
The HFCM acts as a primary fuel filter/water separator which removes
both water and impurities from the fuel. The engine-mounted fuel filter
and the HFCM filter should be changed at the recommended service
interval. Refer to theScheduled maintenance guidesection of this
manual for more information.
The HFCM should be drained at
regular intervals or when the
WATER IN FUEL light illuminates in
the instrument cluster.
The fuel injectors are located in the center of the combustion chambers
in the cylinder head between the rocker arm assemblies. The glow plug
system and fuel injection system are controlled through the Powertrain
Control Module (PCM) and Fuel Injection Control Module (FICM).
Fuel is drawn from the fuel tank by a frame-mounted electric fuel pump.
The fuel pump provides pressurized fuel to the engine and is
electronically controlled by the fuel pump PCM relay. The fuel pump
contains a pressure relief valve for overpressure protection in the event
of restricted flow.
Lubrication system
It is important to change the engine oil at the recommended service
intervals, because oil viscosity is important in maintaining the oil
pressure required to actuate the fuel injectors. Extended oil change
intervals can negatively affect engine performance, fuel economy and
engine life. Refer to the engine oil specification chart located under
Engine oil specificationsin theGeneral maintenance information
chapter.
Diesel information
4

Air filter restriction gauge
The restriction gauge, located on
the upper housing of the air cleaner
assembly, monitors the condition of
the air filter element in two ways:
First, the colored indictor inside the gauge highlights the percentage that
the air filter element is clogged with dust or contaminants. Refer to
Engine CompartmentinService Pointschapter.
Second, the gauge contains an electrical switch which illuminates a
warning light on the instrument cluster when the air filter element is
100% clogged. Refer to theWarning lightschapter.
Check the air filter restriction gauge whenever the hood is raised to
perform general engine maintenance. If the vehicle is operated in
extremely dusty conditions, check the gauge at least every 800 km (500
miles), or two weeks, whichever comes first.
The air filter element must be
replaced when the colored band on
the gauge reaches the CHANGE
FILTER mark. Engine performance
and fuel economy are adversely
affected when the maximum
restriction is reached.
Blowing-out the air filter element with compressed air is not
recommended as the compressed air may damage the filter paper.
Note:It is not possible to determine the level of filter clogging by visual
appearance alone. A filter which appears to be dirty may actually have
several thousand kilometers (miles) of life remaining.
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6

Always use the underhood air filter restriction gauge or engine
air filter warning light on the instrument cluster to determine
when the air filter element needs to be changed.
After servicing the air filter element,
reset the restriction gauge by
pressing the button on the end of
the gauge.
Note:If the vehicle is operated in a heavy snow storm, in blowing snow
or the vehicle is equipped with a snowplow, the engine air filter element
may become partially clogged with snow and/or ice. If this occurs, the air
filter restriction gauge will move to the CHANGE FILTER mark and the
engine may experience a significant reduction in power output. The
vehicle may be driven under these conditions for up to 400 km (250
miles) without damage to the engine or related components.
At the earliest opportunity, clear all snow and ice from the air induction
system and replace the air filter element, or remove the element and dry
it out. Reset the restriction gauge by pressing the button on the end of
the gauge.
The air filter warning light on the instrument cluster may be used, in
addition to the underhood restriction gauge, to monitor the condition of
the air filter element. Refer to theWarning lightschapter.
Diesel information
7