Toyota idle throttle opening is 18%.

No problem. The function of the throttle position sensor is to convert the position or opening of the throttle into a voltage signal and transmit it to the electronic control unit as the basis for the electronic control unit to judge the working condition of the engine, so as to realize the fuel injection control under different throttle openings.

There are three kinds of throttle position sensors: linear pure bridge type, switch type and comprehensive type (both switch and linear variable resistor). The throttle position sensor is installed on the throttle body and linked with the throttle. Inside the throttle position sensor is a sliding potentiometer whose sliding contact is driven by the throttle shaft. The resistance of potentiometer is different with different throttle opening, so the throttle opening is converted into resistance or voltage signal and transmitted to microcomputer.

Through the throttle position sensor, the microcomputer can obtain the analog signal representing the continuous change of all throttle openings from fully closed to fully open, and the change rate of throttle opening, so as to judge the working condition of the engine more accurately and improve the control accuracy and effect. In order to accurately detect the signal of idle working condition (throttle fully closed), the comprehensive throttle position sensor has an idle contact. When the throttle valve is completely closed, the idle output contact is turned on and the sensor outputs an idle signal. At this time, the ECU will instruct the fuel injector to increase the fuel injection quantity to enrich the mixture.