lets simplify what saxonmike just said
yes there are two position sensors in the accelerator sensor (pot)

APP1 and APP2 , these are the high and low range sensors and both are built into the pot/position sensor itself. So dont let that 'having 2 pots' fool you into looking for a second potentiometer/sensor.

The chances are its out of calibration and MAYBE you can recalibrate it and the code will go away.
Most of the time you wind up replacing it anyway so just order a new one and replace it because there is something worn inside it causing it to go 'out of range' triggering the code.