DIESEL ENGINE INFORMATION
The Diesel engine fuel system consists of:
•a frame-mounted electric fuel supply pump
•an engine mounted fuel filter/water separator
•a fuel restriction sensor
•a unit injector for each cylinder
The combination fuel filter/water separator removes both water and
impurities from the fuel. The filter should be changed at the
recommended service interval. Refer to the scheduled maintenance guide
for more information. The filter bowl 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).
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 and fuel economy.
Pressurized oil from the turbocharger is also used to actuate an exhaust
backpressure warm-up system (if equipped). Pressurized oil from the
turbocharger is routed to the exhaust backpressure actuator. During
exhaust backpressure operation, the engine’s sound will be altered and
you may notice a change in engine performance while it’s engaged. This
function occurs only during cold weather warm-up cycle.
Fast start glow plug system
The glow plug system consists of:
•eight glow plugs
•the glow plug relay
Diesel information
4
IF THE ENGINE WON’T CRANK
Turn on the headlights. If the lights are dim, do not go on at all or if
when the ignition is turned to START the lights become dim or go out,
the battery connections may be loose or corroded, or the battery may be
discharged. If there is a clicking or stuttering sound coming from the
engine compartment when you turn the key to START, this may also
indicate a loose or corroded battery connection.
Check the battery connections at the battery posts, cable connection to
the engine grounding point and at the starter relay terminals. Also, make
sure the relay bracket is securely fastened to its mounting surface.
If the starter relay clicks, but the starter does not crank, check the
connections at the starter terminal. If a discharged battery is suspected,
have it checked and corrected.
•For vehicles with manual transmissions, the clutch pedalmustbe fully
depressed in order for the starter to operate.
•For vehicles with automatic transmissions, the gearshift lever must be
in Park or Neutral in order for the starter to operate.
•Try operating the starter switch several times. Should the switch be
corroded, this operation may clean the contacts or make the switch
temporarily operable until you can reach the dealer.
•If all electrical connections are tight and you need assistance to start,
see“Jump Starting Your Vehicle”.
IF ENGINE CRANKS BUT WON’T START
Prolonged starter cranking (in excess of 30 seconds) could cause
damage to the starter motor.
•Check the fuel gauge. You may be out of fuel. If the gauge shows that
there is fuel in the tank, the trouble may be in the electrical system or
the fuel system. If equipped with an auxiliary tank, be sure that the
tank control switch is set for the tank with fuel and not on an empty
tank.
•Leaving the ignition key ON for over two minutes without starting may
make starting difficult because the glow plugs will cease activation.
Reset the system by turning the ignition key to OFF and then back to
ON again.
Minor troubleshooting guide
46
