Functions of the Engine Control Module
The engine control module basically controls the intersection of the engine's
necessary ingredients to make energy -- fuel, air and spark. That
sounds simple, kind of in the same way an engine itself sounds simple if
you break it down into really basic terms. But the ECM accomplishes its
considerable chore by constantly monitoring a vast network of sensors
around the car to ensure conditions are within normal operating range.
When something goes wrong, the ECM adjusts conditions or, if it can't,
the car won't run properly or at all. When there's a problem, the ECM
stores a trouble code so it can be diagnosed by a mechanic (with a
scanner specifically designed for that purpose) and triggers the check engine light so the driver knows something's wrong.
Newer engine computer systems also feature lightweight, low-cost
memory systems that can be easily accessed by the dealership to fix
programming issues and update specifications (kind of like running a
system or software update on your computer).
cent tasks (in the last decade or so, anyway) delegated to the engine computer
came about only as automotive companies switched from mechanical
throttle control to electronic throttle control. Previously, when your
foot made contact with the gas pedal, it was connected to a cable that
went directly to the engine so the engine could decide how much fuel to
inject, based on whether you caressed the pedal, mashed it to the floor,
or most likely, somewhere in between. Now, an electronic sensor at or
near the gas pedal sends a signal via electrical wire to the engine
management system, which evaluates your throttle contact and then sends a
signal to the engine to adjust fuel dosage.
Part of the ECM's start-up procedure is to calibrate the position
of the throttle at idle -- in other words, remind itself, and the
throttle, how the engine should run when it's not being given any gas.
This helps control and prevent an uneven idle. If all the sensors
involved don't agree on the right position, the computer will send a
signal to the engine and transmission to run in Limp Mode (preventing
the driver from achieving high speeds that could get out of hand) and
also sends an alert to the instrument cluster. The idea is to allow it
to run well enough to get to a repair shop, but not strand you on the
side of the road.
The ECM also makes sure the car meets emissions standards, by
monitoring and regulating the fuel mixture to ensure the engine isn't
running too rich and emitting pollutants beyond the established
parameters. And with all those sensors already in place, the ECM is
often responsible for managing features like anti-skid brakes, cruise
control and theft protection.
That sounds like a lot to keep straight, doesn't it? So, on top of
it all, the engine control module, unit, or what have you, runs through
a recalibration test every time you turn on the car, just to make sure
signals don't get crossed
functions of engine control module
functions of engine control unit
what is the function of the engine control module.
functions of engine control unit
what is the function of the engine control module.
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