Engine and Emission Control Parts Description
EF & EC-375prose procedureI.A.A. unit and A.A.C. valve shown for both SR20DE and SR20DET.
Idle Air Adjusting (I.A.A.) Unit
The I.A.A. unit is made up of the A.A.C. valve, F.I.C.D. solenoid valve and idle adjusting screw. It receives the signal from the E.C.U. and controls the idle speed at the preset value.
Auxiliary Air Control (A.A.C.) Valve
The E.C.U. actuates the A.A.C. valve by an ON/OFF pulse. The longer that ON duty is left on, the larger the amount of air that will flow through the A.A.C. valve.
Vehicle Speed Sensor
The vehicle speed sensor provides a vehicle speed signal to the E.C.U. The speed sensor consists of a reed switch, which is installed in the speedometer unit and transforms vehicle speed into a pulse signal.
Power Steering Oil Pressure Switch
The power steering oil pressure switch is attached to the power steering high-pressure tube and detects the power steering load, sending the load signal to the E.C.U. The E.C.U. then sends the idle-up signal to the A.A.C. valve.