The Engine Control Module (ECM) pinouts and diagram herein applies for Subaru Impreza RS 2004 models years. The ECM consists of electronics which are mounted on multi-layer circuit board. It monitors the input and output signals produced by various sensors in the system then adjusts the system as necessary e.g. ECMs determine the quantity of fuel, ignition timing and other parameters by monitoring the engine through sensors and/or determine the quantity of fuel to inject based on a number of parameters.
In this manual, you will find the detail diagram of Impreza RS ECM pinout which consists of Crankshaft position sensor, camshaft position sensor, throttle position sensors, rear oxygen sensor, front oxygen sensor heater, engine coolant temperature sensor, vehicle speed signal, starter switch, A/C switch, ignition switch, test mode connector, fuel pump relay control, radiator main fan relay control, power steering switch, etc.