Circuit Description

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

The throttle position sensor is mounted in the accelerator pedal to detect the opening angle of the accelerator pedal. Since this sensor is electronically controlled with hall elements, accurate control and reliability can be obtained. See Figure. It uses 2 sensors to detect the accelerator position and a malfunction of the accelerator position sensor. In the accelerator pedal position sensor, the voltage applied to pedal terminals VPA and VPA2 of the ECM change between 0 volt and 5 volts, in proportion to the opening angle of the accelerator pedal. VPA is a signal that indicates the actual accelerator pedal opening angle which is used for engine control, and VPA2 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 accelerator pedal from these signals input from terminals VPA and VPA2. ECM controls the throttle motor based on these signals. If this DTCs is stored, the throttle valve is locked at a certain opening angle. The whole electronically controlled throttle operation is cancelled until the system returns to normal and the ignition switch is turned OFF. However, the maximum opening angle of the accelerator pedal is limited to 22° when either VPA or VPA2 circuit is abnormal.