183 / 1232
Revotron 1.2T
136
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.