Circuit Description
The idle speed is controlled by the Electric Throttle Control System (ETCS).
The ETCS is composed of: 1) the throttle motor, which operates the throttle valve; 2) the magnetic clutch, which connects the throttle motor with the throttle valve; 3) the throttle position sensor, which detects the opening angle of the throttle valve; 4) the accelerator pedal position sensor, which detects the accelerator pedal position; 5) the ECM, which controls the ETCS and 6) a one valve type throttle body.
The throttle position sensor, which is mounted on the throttle body, detects the opening angle of the throttle valve, and it provides feedback to the ECM to control the throttle motor.
If the ETCS has malfunction, the ECM shuts down the power for the throttle motor and the magnetic clutch, and the throttle valve is fully closed by the return spring.
However, the opening angle of the throttle valve can be controlled by the accelerator pedal through the throttle cable.