How can i know the cause and fix it -Daf cf85-360?

Daf cf85-360 year2007 has developed a problem with the gas pedal. When the vehicle is idle,the engine rpm rises to 10 instead of normal 5.when trying to move the vehicle,the rpm rate would descend to 5.this result to it not movable. on the dash board gives the yellow signs of ACCELERATOR PEDAL-SENSOR,BODY BUILDER MODULE,ENGINE WARNING and EXHAUST SYSTEM WARNING. mechanics have tried to replaced the gas pedal-sensor and have done service to the Adblue system,but still the problem is not solved.would some one pls. help me with the reason and answer?
best regards