July 1: So it begins. Don't worry, this is not in the correct legal jurisdiction!
Accelerator Pedal Position (APP) Sensor
WARNING: This page is about a different car, the 2006 Acura MDX, 2005 Acura MDX, 2004 Acura MDX, and 2003 Acura MDX. However, it is still accessible from the selected car via links, so may be relevant.
As the accelerator pedal position changes, the sensor varies the signal voltage to the PCM.