according manual it is connected the plug to override the magnetic brake, check below information..
Code br_o (C16)
Code C19
Code HPd (C20)
Code Title Brake Override
Operator Display br_o
TA Flash Code "5,6"
System Response Travel, lift, and lower are disabled.
Alarm Sounds No
Reason Brake Override jumper (JP12) connector is connected to manually move the truck.
Tests to Run None
How to Clear Move the tiller arm to the upper brake position and disconnect the brake override
jumper connector (JP12).