Monitor Description
WARNING: This page is about a different car, the 2004 Lexus IS 300. However, it is still accessible from the selected car via links, so may be relevant.
The accelerator pedal position sensor is mounted on the accelerator pedal bracket and consists of two sensors VPA and VPA2. The PPA is used to detect accelerator pedal position, and the VPA2 is used to monitor the VPA and detect faults in the sensor itself. When difference between voltage outputs, of the VPA or VPA2 deviates from the standard range, the ECM concludes that there is a defect in the accelerator pedal position sensor. The ECM turns on the MIL and a DTC is set.