Perkins 1106C Genset Systems Operation Testing And Adjusting page 29

KENR6931
ECM
Illustration 32
Typical example
The Electronic Control Module (ECM) (1) functions
as a governor and a computer for the fuel system.
The ECM receives signals from the sensors in order
to control the timing and the engine speed.
The electronic system consists of the ECM, the
engine sensors and inputs from the parent machine.
The ECM is the computer. The flash file is the
software for the computer. The flash file defines the
following characteristics of the engine:
•
Engine power
•
Torque curves
•
Engine speed (rpm)
•
Engine Noise
•
Smoke and Emissions
The factory passwords restrict changes to authorized
personnel. Factory passwords are required to
clear any event code. Refer to the following
Troubleshooting, "Factory Passwords" for more
information on the passwords.
The ECM has an excellent record of reliability. Any
problems in the system are most likely to be the
connectors and the wiring harness. The ECM should
be the last item in troubleshooting the engine.
The flash file contains the software with all the fuel
setting information. The information determines the
engine performance.
Flash programming is the method of programming
or updating the flash file. Refer to the following
Troubleshooting, "Flashing Programming " for the
instructions on the flash programming of the flash file.
The ECM is sealed and the ECM needs no routine
adjustment or maintenance.
Engine Speed Governor
The electronic controls determine the injection timing,
the amount of fuel that is delivered to the cylinders
and the intake manifold pressure if an electronically
controlled wastegate is installed on the turbocharger.
These decisions are based on the actual conditions
and the desired conditions at any given time.
The governor has software that compares the desired
engine speed to the actual engine speed. The actual
engine speed is determined through the primary
speed/timing sensor and the secondary speed/timing
sensor. If the desired engine speed is greater than
g01199973
the actual engine speed, the governor injects more
fuel in order 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 sensor for the intake manifold air temperature
•
The sensor for the intake manifold pressure
• Speed/timing sensors
At start-up, the ECM determines the top center
position of the number 1 cylinder from the secondary
speed/timing sensor in the fuel injection 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 unit injectors are supplied high
pressure fuel from the fuel injection pump. The ECM
also provides the signal to the solenoid in the fuel
injection pump. The solenoid in the fuel injection
pump controls a valve in the fuel injection pump. This
valve controls the pressure in the fuel injection pump.
Fuel that is not required for the engine is diverted
away from the fuel injection pump back to the fuel
tank.
The ECM adjusts injection timing and fuel pressure
for the best engine performance, the best fuel
economy and the best control of exhaust emissions.
The actual timing can be viewed with an electronic
service tool. Also, the desired timing can be viewed
with an electronic service tool.
Systems Operation Section
29