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 theMaintenance and specifcations
chapter.
Fast start glow plug system
The glow plug system consists of:
•eight glow plugs
•the glow plug control module (GPCM)
•engine oil temperature (EOT) sensor
•barometric pressure (BARO) sensor
The glow plug system is
electronically controlled by the
PCM. The GPCM energizes the glow
plugs immediately after the ignition
is placed in the ON position, then determines how long the glow plugs
will be on according to the EOT and BARO sensors. The required time
for the glow plugs to be energized decreases as the engine oil
temperature and barometric pressure increase.
Engine cooling system
The cooling system contains an engine oil cooler which is mounted in the
center valley of the engine. The cooler’s function is to regulate engine oil
temperature.
Introduction
4
