So, I do have conneted the groud and sense low together with a jumper in the pcb
See the kaupoi pcbv4 schematic :
From the pcb the wiring continues with three wires to was. In the wire harness, where this Y cable is I have divedied the signal only to go to different ecu in tractor, so the automatic front diff lock ability continues to work. This is just specific to these cnh machines, not related to ago.