Brake might be getting ready to go out or solenoid for the brake activation. When that happened on our M600 you would go to walk the press the inch alarm would go off and then the red light would flash and press wouldn't move, could try to inch it again and it would move (sometimes). Also the encoder will act the same way. But these are just some ideas to look into. I tried looking for that stop code in the cptronic manual and there wasn't anything for it. Sorry I couldn't be of more help