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1.2L REVOTRON ENGINE
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B. An Overview :
Engine Management System Overview :
Modern engine management systems do a fine
job of ensuring that engines run cleanly and
efficiently in a wide variety of conditions, they are
for the most part reliable and require little or no
maintenance.
Engine management system Comprises of
Electronic Control Unit (ECU), Sensors,
Actuators, Wiring Harness and control algorithms,
which determine the performance of the Engine
as a whole and as part of the vehicle.
Electronic Control Unit (ECU) :
An engine control unit (ECU), now called the
power train control module (PCM), is a type of
electronic control unit that controls a series of
actuators on an internal combustion engine to
ensure optimal engine performance. It does this
by reading values from a multitude of sensors
within the engine bay or signals from other vehicle
electronic control units through Controller Area
Network (CAN), interpreting the data using
multidimensional performance maps (called
lookup tables), and adjusting the engine actuators
accordingly.
Modern ECUs use a microprocessor which can
process the inputs from the engine sensors in
real-time. An electronic control unit contains the
hardware and software (firmware). The hardware
consists of electronic components (ADC’s, H
bridges, CAN Transceiver, MUX, Low side and
High side drivers) on a printed circuit board
(PCB), ceramic substrate or a thin laminate
substrate. The main component on this circuit
board is a microcontroller chip (CPU). The
software is stored in the microcontroller or other
chips on the PCB, typically in EPROMs or flash
memory so the CPU can be re-programmed by
uploading updated code or replacing chips. This is
also referred to as an (electronic) Engine
Management System (EMS).
Engine control unit monitors/diagnoses the
functionality of its Hardware I/O’s, Software
algorithms & external interfaces and raises a
Diagnostic trouble code (DTC) against a
peripheral when it finds mal-functioning of that
peripheral. Apart from logging a DTC, Engine
Control Unit also alerts the user with MI Lamp /
CE lamp Glowing/flashing. Engine Control Unit
also conveys the information regarding Engine
operating condition through Dynamic / Static
Defined data identifiers.
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.
Wiring Harness :
Engine Wiring Harness and Vehicle Wiring
Harness interface the Engine and Vehicle
components to Engine Control Unit.