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Home >> Subaru >> 2012 >> Legacy GT Limited >> Repair and Diagnosis >> Engine Performance >> Engine Control Systems >> Fuel Injection System - Mechanism & Function (H4DOTC) >> Control System >> Input And Output Signals
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Input And Output Signals

Signal Unit Function
Input signals Manifold absolute pressure sensor Detects the pressure (measures the absolute pressure) of intake air.
Mass air flow and intake air temperature sensor Detects the temperature and amount of intake air.
Throttle position sensor Detects the throttle valve position.
Front oxygen (A/F) sensor Detects the density of oxygen in exhaust gases at the upstream of the front catalytic converter.
Rear oxygen sensor Detects the density of oxygen in exhaust gases at the downstream of the front catalytic converter.
Crankshaft position sensor Detects the crankshaft angular position.
Camshaft position sensor Detects the combustion cylinder.
Engine coolant temperature sensor Detects the engine coolant temperature.
Knock sensor Detects engine knocking.
Accelerator position sensor Detects the position of the acccelerator pedal.
Exhaust gas temperature sensor Detects the exhaust gas temperature.
Fuel temperature sensor Detects the temperature of the fuel in the fuel tank.
Fuel tank pressure sensor Detects the evaporation gas pressure in the fuel tank.
Ignition switch Detects operation of the ignition switch.
Starter switch Detects the condition of engine cranking.
Neutral position switch (MT) Detects that the gear is in neutral.
Inhibitor switch (AT) Detects shift positions.
A/C switch Detects ON-OFF operation of the A/C switch.
Power steering switch Detects the steering condition.
Output signals Fuel injector Activates an injector.
Ignition signal Turns the primary ignition current ON or OFF.
Electronic control throttle Controls motor output to the electronic control throttle.
Oil flow control solenoid valve Controls oil pressure for oil flow control solenoid valve.
Fuel pump control unit Controls the fuel pump.
A/C control relay Turns ON or OFF the A/C control relay.
Radiator fan control relay Turns ON or OFF the radiator fan control relay.
Wastegate control solenoid valve Controls supercharging pressure
Engine malfunction indicator light (MIL) Indicates existence of abnormality.
Purge control solenoid valve Controls purge of evaporative gas absorbed by the canister.
Tumble generator valve actuator Operates the tumble generator valve.
Pressure control solenoid valve Controls evaporation pressure in fuel tank.
Drain valve Closes the evaporation line between the fuel tank and canister to detect leakage of evaporation gases.
Oil flow control solenoid valve Controls advance and retard angles of the intake valves.
Heater circuit of front and rear oxygen sensors Controls the heater of the front and rear oxygen sensors.
Electronic control throttle motor cut relay Turns ON-OFF the electronic control throttle motor relay.
Power supply Controls ON/OFF of the main power supply relay.