I don't know how old your MP4 controller is but some of the very early vector controllers did not support pedelec.
Try increasing the "
(PAS Ratio ( 0.1 times )" setting to 50 and see if it makes any difference, and also try pedalling backwards to see if you get any response. This can sometimes happen when the magnet ring has been fitted with the arrow facing the wrong direction.
If it responds when you pedal backwards, you will need to turn the magnet ring around so it rotates in the right direction.
On my original Magic Pie I seem to recall it only responded to one side of the magnet ring and only in one direction, which meant it had to be swapped to the other side of the bottom bracket for it to work correctly.
With the power turned off, unplug the BAC-601 Display unit and see if it makes any difference.
(My pedelec still worked at a fixed level without the display unit connected)If there is no response whatsoever, you may need to email David at Golden Motor in China
and see if he can help.
Alan P.S. It makes a change to see some substantial torque arms which should definitely prevent the axle from spinning in the dropouts.