Accelerator Pedal Position Sensor
WARNING: This page is about a different car, the 2003 Lexus GX 470. However, it is still accessible from the selected car via links, so may be relevant.
Accelerator pedal position sensor is located on top of accelerator pedal assembly. If circuit or component is faulty, a Diagnostic Trouble Code (DTC) should set. Retrieve DTCs and perform appropriate diagnostic test. See DTC P0120, P0122, P0123, P0220, P0222 OR P0223 in SELF-DIAGNOSTICS - GX470 article.