Operation CHARM: Car repair manuals for everyone.
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

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EEC Sub-System


The EEC sub-system consist of the ECA and various sensors and actuators. The ECA reads inputs from the sensors to compute the required fuel flow rate necessary to achieve the desired air/fuel ratio. This is performed by the ECA controlling outputs to the fuel injectors. The period of time that the injectors are energized (injector ON-time or pulse width) determines the amount of fuel delivered to each cylinder. The ECA calculates the injector pulse width (ON-time), commands the injectors to fire, delivering the appropriate quantity of fuel required