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ENGINE 273 MPFI
AN OVERVIEW
EMS (Engine Management System)
Engine Management System (EMS) comprises of
Electronic Control Unit (ECU), sensors, actuators and
control algorithms that determine the performance of
the Engine as a whole and as part of the vehicle.
ECU (Electronic Control Unit)
Electronic Control Unit (ECU) as a system consists
of amicroprocessor with peripheral devices like ignition
driver, ADCs device and I/O drivers. ECU read values
from the sensors and uses the sensor readings to
control the fuel injection and ignition systems.
It is the ‘Brain’ of the Engine Management system,
which controls all the actuators based on the
processing of the Sensors inputs in conjunction with
various control algorithms for the optimum working of
the Engine/Vehicle. Being the most important
component of the Engine management system, ECU
apart from ensuring the optimum working of the
Vehicle, also keeps an eye on the working of the
sensors and actuators. When ever a malfunction/fault
occurs in the component or the system the ECU alerts
the user by glowing CKNL (Service Indicator). Apart
from glowing the CKNL (Service Indicator), ECU also
does the following:
•
Stores a DTC in its memory (indicates the faulty
component/system).
•
Stores a context frame (list of parameters indicating
the operating condition during the fault generation)
in its memory.
Sensors
A sensor is a device that measures a physical quantity
and converts it into an electrical voltage which can be
read by an instrument or used by some controller for
its purpose.
Actuators
An actuator causes an action (say injector open or
close) based on command given by ECU.