yes
no load you will have a + volt signal
when load you will see 0v

pretty much any control these days uses negative switching so generally you will see a + voltage when no load.

reading these codes are not like most codes
they are broken down into segments
E designates it as an event code
1 designates the function group which is 'travel'
5 designates the event group which is 'hardware'
04 designates the event number which is an output error in phase of V and W phase of transformer.

manual recommends replacement of controller.

now in some cases you can remove the cover of the controller and access the internal circuit boards and there should be ribbon cables connecting them together, i have seen these vibrate loose and cause errors such as this. Caterpillars fix was to clean, reinsert the connectors and apply silicone sealer to hold them in place.

Also i have seen tech's overtorque the cables and actually break the standoff loose from the heatsink inside the controller, if this is the case there is no fix for this and the controller has to be replaced.

good luck, hope this helps