This machine has electronic flow regulator - solenoid for hydraulic pump. If there is something wrong with the potentiometer (theoretical rpm) or alternator (actual rpm) the machine goes to the "safety" mode. Or if the cables are broken in short circuit etc.. it goes to safe mode.
If you want to check this you have to have a "Manitou" diagnostic case or Rexroth handheld (only for older electronic - round connector).
If you have to change the potentiomer (it's on the fuel pump) you have to do "teach in" for electronic after you have adjusted it mechanicaly.
Try playing with different positions of this potentiometer or check the alternator if it's working correctly (W cable for rpm). If one of this two signals is different (the electronic compares them with each other by different rpm's) more than 50 rpm (by aprox. 1000 rpm), 150 rpm (by aproximately 1700 rpm) and 250 rpm (by maximum rpm 2.500) the machine goes to safety mode.
Look for broken wires on alternator or potentiometer or bad fuse on the ECM (black box by side where the arm rests when under the plastic cover).

Hope this helps.