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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.