6 KENR6933
Troubleshooting Section
The 1106C Genset was designed for electronic
control. The en
gine has an Electronic Control Module
(ECM), a fuel rail pump and electronic unit injectors.
All of these items are electronically controlled. There
arealsoanumb
er of engine sensors. Turbocharged
engines can be equipped with an electronically
controlled wastegate for the turbocharger. The ECM
controls the
engine operating parameters through
the software within the ECM and the inputs from the
various sensors. The software contains parameters
that contro
l the engine operation. The parameters
include all of the operating maps and customer
selected parameters.
The electronic system consists of the ECM, the
engine sensors and inputs from the parent machine.
The ECM is th
e computer. The personality module
is the software for the computer. The personality
module defines the following characteristics of the
engine:
•
Engine power
•
Torque curves
•
Engine spe
ed (rpm)
•
Engine Noise
•
Smoke and Emissions
Engine Spe
ed Governor
The ECM determines the injection timing, the amount
of fuel tha
t is delivered to the cylinders and the intake
manifold pressure if an electronically controlled
wastegate is installed on the turbocharger. These
decision
s are based on the actual conditions and the
desired conditions at any given time.
The gover
nor has software that compares the desired
engine speed to the actual engine speed. The actual
engine speed is determined through the primary
speed/t
iming sensor and the secondary speed/timing
sensor. If the desired engine speed is greater than
the actual engine speed, the governor injects more
fuel in o
rder to increase engine speed.
Timing Considerations
Fuel injection timing is determined by the ECM after
considering input from the following components:
•
Engine coolant temperature sensor
•
The sens
or for the intake manifold air temperature
•
The sensor for the intake manifold pressure
•
Speed/timing sensors
•
Speed demand input
At start-up, the ECM determines the top center
position of the number 1 cylinder from the secondary
speed/timing
sensor in the fuel rail pump. The ECM
decides when fuel injection should occur relative to
the top center position. The ECM optimizes engine
performance
by control of each of the electronic
unit injectors so that the required amount of fuel is
injected at the precise point of the engine’s cycle. The
electronic u
nit injectors are supplied high pressure
fuel from the fuel rail. The ECM also provides the
signal to the solenoid in the fuel rail pump. The
solenoid in
the fuel rail pump controls a valve in the
fuel rail pump. This valve controls the pressure in
the fuel rail. Fuel that is not required for the engine
is diverted
away from the fuel rail pump back to the
fuel tank.
The ECM adju
sts injection timing and fuel pressure
for the best engine performance, the best fuel
economy and the best control of exhaust emissions.
The actual
timingcanbeviewedwithanelectronic
service tool. Also, the desired timing can be viewed
with an electronic service tool.
Fuel Injection
The perso
nality module inside the ECM sets certain
limits on the amount of fuel that can be injected.
The Fuel R
atio Control Limit is a limit that is based
on intake manifold air pressure and engine rpm. The
FRC Limit is used to control the air/fuel ratio in order
to contro
l the engine’s exhaust emissions. When the
ECM senses a higher intake manifold air pressure,
the ECM increases the FRC Limit. A higher intake
manifol
d air pressure indicates that there is more air
in the cylinder. When the ECM increases the FRC
Limit, the ECM allows more fuel into the cylinder.
The Rated Fuel Limit is a limit that is based on the
power rating of the engine and on the engine rpm.
The Rat
ed Fuel Limit enables the engine power and
torque outputs to conform to the power and torque
curves of a specific engine model.
These limits are in the personality module and these
limits cannot be changed by the operator.
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