I have a John Deere 650K SN 1T0650KKCNF429168 that has the stored code VCU 004089.04 Hydraulic system pressure sensor fault and throws it twice a day. It is under the service code and it is not a stop code does anyone have any idea what can cause this?
Most likely a wiring/connection issue. That circuit runs through multiple connectors, so corrosion/looseness could be an issue. An .04 code indicates voltage out of range low and the code indicates it is the 5 volt reference (P081 Red wire) that is low. To me, that indicates a short to ground, either in the wiring, or the sensor itself.
Do you think that it could be the sensor? I will look over the wiring.
I can't answer that. Testing has to be done to determine that.