Circuit Description (With ETCS)

The throttle position sensor is mounted on the throttle body and has 2 sensors to detect the throttle opening angle and a malfunction in throttle position sensor circuit. The voltage applied to the terminals VTA and VTA2 of ECM changes between zero and 5 volts in proportion to the opening angle of the throttle valve. The VTA signal indicates the actual throttle valve opening angle which is used for the engine control, and the VTA2 signal indicates the information about the opening angle which is used for detecting a malfunction. The ECM determines the current opening angle of the throttle valve from these signals input from terminals VTA and VTA2. ECM controls the throttle motor to make the proper throttle valve angle in response to the driving condition. If this DTC is stored, the ECM shuts down the power for the throttle motor and the electromagnetic clutch. 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.