Subaru 2002 Impreza Service Manual page 43

CONTROL SYSTEM
Fuel Injection (Fuel System)
B: INPUT AND OUTPUT SIGNALS
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Function
Detects the temperature of intake and amount of intake air (Mea-
sures the absolute pressure).
Detects the amount of intake air (Measure the atmospheric pres-
sure).
Detects the throttle valve position.
Detects the density of oxygen in exhaust gases at the upstream of
the front catalytic converter.
Detects the density of oxygen in exhaust gases at the downstream
of the front catalytic converter.
Detects the crankshaft angular position.
Detects the combustion cylinder.
Detects the engine coolant temperature.
Detects engine knocking.
Detects the vehicle speed.
Detects operation of the ignition switch.
Detects the condition of engine cranking.
Detects that the gear is in neutral.
Detects shift positions.
Controls engine torque.
Detects abnormality in the heater circuit of the front and rear oxygen
sensors.
Detects the self-diagnostics of the TCM.
Detects ON-OFF operation of the A/C switch.
Detects the temperature of the fuel in the fuel tank.
Detects the level of the fuel in the fuel tank.
Detects the evaporation gas pressure in the fuel tank.
Detects ON-OFF operation of the small light switch.
Detects ON-OFF operation of the blower fan switch.
Detects ON-OFF operation of the rear defogger switch.
Activates an injector.
Turns the primary ignition current ON or OFF.
Turns the fuel pump relay ON or OFF.
Turns the N C control relay ON or OFF.
Turns the radiator fan control relay ON or OFF.
Adjusts the amount of air flowing through the bypass line in the
throttle body.
Indicates existence of abnormality.
Controls purge of evaporative gas absorbed by the canister.
Control ON/OFF of the main power supply relay.
Controls evaporation gas pressure in the fuel tank.
Closes the evaporation line between the fuel tank and canister to
detect leakage of evaporation gases.
Signal
Unit
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Intake air temperature and pressure
sensor
Atmospheric pressure sensor
Throttle position sensor
Front oxygen (NF) sensor
Rear oxygen sensor
Crankshaft position sensor
Camshaft position sensor
Engine coolant temperature sensor
Knock sensor
Vehicle speed sensor
Ignition switch
nput signals
Starter switch
Neutral position switch (MT)
ParWNeutral position switch (AT)
Torque control signal (AT)
Heater circuit of front and rear oxy-
gen sensor
Diagnostics of TCM (AT)
N C switch
Fuel temperature sensor
Fuel level sensor
Fuel tank pressure sensor
Small light switch
Blower fan switch
Rear defogger switch
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3utput signals
Fuel Injector
Ignition signal
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Fuel pump relay
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N C control relay
Radiator fan control relay
Idle air control solenoid valve
Malfunction indicator lamp
Purge control solenoid valve
Power supply
Pressure control solenoid valve
Drain valve
FU-27