the codes foe 520 and 530
520 flywheel diode traction open or short
code 530 has several thing to it transister on traction/pump and ps[current sensour] could be a diode sensour.
rb transister/fr contactor/by pass rb on traction
ps contactor on ps.flywheel diode on traction or pump plugging diode on traction. current sensour trac/pump and ps accel sensour traction ps over current ps faulty motor. steeering sensour ps faulty motor. i hope you can understand it