Hello Nuna
Your error is interested.It would be great if you have another same truck to try some parts.When you do acc on pedal pot look in screen and read is it voltage in operating values if not you need to move pot with hand and than to calibrate.Is it wiring of pot ok?
look battery on display sometime she know to be problem on still trucks just check it.And look CAN good because error that you have says that display dont receive data from traction converter.
If you can please replace pedal pot or every part that you think that dont work good,Calibrate all needed and check truck data are they ok for that vehicle.
Tell me what are you do.
Good Luck