Circuit Description

WARNING: This page is about a different car, the 2003 Toyota 4Runner. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: This electrical throttle system does not use throttle cable.

This throttle position sensor is non-contact type. The throttle position sensor is mounted on the throttle body to detect the opening angle of the throttle valve. Since this sensor is electronically controlled with hall elements, accurate control and reliability can be obtained. It has 2 sensors to detect the throttle opening angle and a malfunction of the throttle position sensor. The voltage is applied to the terminals VTA1 and VTA2 of the ECM. Voltage changes between zero volt and 5 volts in proportion to the opening angle of the throttle valve. The VTA1 is a signal to indicate the actual throttle valve opening angle which is used for engine control. VTA2 is a signal that 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 VTA1 and VTA2. ECM controls the throttle motor to make the throttle valve angle directly in response to the driving condition. When a malfunction is detected, the throttle valve is locked at a certain opening angle. Also, the whole electronically controlled throttle operation is cancelled until the system returns to normal and the ignition switch is turned OFF.