Impreza Sedan AWD F4-1820cc 1.8L SOHC (1993)
![background image](/subaru/impreza_sedan_awd/f4-1820cc_1.8l_sohc/Page-590001.png)
Engine Control Module: Description and Operation
System Schematic
PURPOSE
The ECM is a computer that calculates signals from various sensors and switches to judge engine operating conditions and sends output signals to
provide precise control and functioning of various systems. Main ECM control functions are:
^ Fuel injection control
^ Ignition system control
^ Pulsed air induction system
^ Exhaust gas recirculation system
^ By-pass air control (idle speed control)