Circuit Description
Throttle position sensor is mounted on throttle body to detect opening angle of throttle valve. Since this sensor is electronically controlled with hall elements, accurate control and reliability can be obtained. It has 2 sensors to detect throttle opening angle and a malfunction of throttle position sensor. Voltage applied to terminals VTA1 and VTA2 of the ECM changes between 0-5 volts in proportion to opening angle of throttle valve. Terminal VTA1 is a signal to indicate actual throttle valve opening angle which is used for engine control, and Terminal VTA2 is a signal to indicate information about opening angle which is used for detecting a malfunction. ECM judges current opening angle of throttle valve from these signals input from terminals VTA1 and VTA2, and ECM controls throttle motor to make throttle valve angle correct in response to driving condition. If these DTCs are stored, the throttle valve is locked at a certain opening angle. See Fig 1. For detection conditions and possible causes, see Fig 2.