trouble code

I have a 1999 New Jetta TDI with approximately 215 000 Kms or 130 000 miles on it. The check engine light came on. I used a scan tool and came up with the code P1256. According to the obd book it is "Pedal correlation PDS 1 HPDS" Can anyone tell me what this means and where the probelem/sensor is that needs to be fixed/repaired? Thank You!! :) :)