Subaru LEGACY 2002 - Control System

Fuel Injection (Fuel System)
CONTROL SYSTEM
FU-29
B: INPUT AND OUTPUT SIGNALS
Signal Unit Function
Input signals
Intake manifold pressure sensor Detects the amount of intake air (Measures the absolute pressure).
Intake air temperature sensor Detects the temperature 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 rear 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.
Front vehicle speed sensor Detects the vehicle speed.
Ignition switch Detects operation of the ignition switch.
Starter switch Detects the condition of engine cranking.
Park/Neutral position switch Detects shift positions.
Diagnostic of AT Detects the self-diagnostics of AT
Heater circuit of front and rear oxygen
sensor
Detects the abnormality in heater circuit of front and rear oxygen sen-
sor.
A/C switch Detects ON-OFF operation of the A/C switch.
Fuel level sensor Detects the level of the fuel in the fuel tank.
Small light switch Detects ON-OFF operation of the small light switch.
Blower fan switch Detects ON-OFF operation of the blower fan switch.
Rear defogger switch Detects ON-OFF operation of the rear defogger switch.
Output signals
Fuel Injector Activates an injector.
Ignition signal Turns the primary ignition current ON or OFF.
Fuel pump relay Turns the fuel pump relay ON or OFF.
A/C control relay Turns the A/C control relay ON or OFF.
Radiator fan control relay Turns the radiator fan control relay ON or OFF.
Idle air control solenoid valve Adjusts the amount of air flowing through the bypass line in the throttle
body.
Induction control solenoid valve Controls induction control valve.
EGR solenoid valve Controls EGR valve.
Malfunction indicator lamp Indicates existence of abnormality.
Purge control solenoid valve Controls purge of evaporative gas absorbed by the canister.
Power supply Controls ON/OFF of the main power supply relay.