Monitor Description
WARNING: This page is about a different car, the 2007 Lexus SC 430. However, it is still accessible from the selected car via links, so may be relevant.
When the difference between voltage outputs of VPA1 or VPA2 deviate from the standard range, the ECM concludes that there is a defect in the accelerator pedal position sensor. The ECM illuminates the MIL and sets the DTC. This monitor runs for 1 second (the first second of engine idle) after the engine is started.