C28- check 10amp fuse or check for stuck lift solenoid

E104- check for broken wire around control handle pivot or check for code 12 flashing on controller indication bad controller

E107-Make sure charge on battery is good before beginning any repair. if battery charge is good check traction fuse ANL-250

E112-Angle arm switch broken or broken wire from switch to controller

E142-check for broken wires at drive motor

E150-If with code 'C28 power amplifier

E157- check for insulation split on CAN-Bus harness

E200- check for broken wire at drive motor

Hope this helps and some of the things I have found over they years the book does not explain clearly