Circuit Description & Possible Causes

WARNING: This page is about a different car, the 2003 Toyota Camry. 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 is procedure of the accelerator pedal position sensor.

The accelerator pedal position sensor is mounted on the accelerator pedal bracket and it has the 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 VPA1 and VPA2 of the engine control module (ECM) changes between 0-5 V, in proportion to the opening angle of the accelerator pedal. The VPA1 is a signal to indicate the actual accelerator pedal opening angle which is used fro the engine control, and the VPA2 is a signal to indicate the information about the opening angle which is used for detecting a malfunction.

The ECM judges the current opening angle of the accelerator pedal from these signals input from terminals VPA1 and VPA2 and the ECM controls the throttle motor based on these signals. See Fig 1.

Fig 1: DTCs P2120, P2122, P2123, P2125, P2127, P2128 & P2138 Circuit Description & Possible Causes