Crankcase pressure

[JimT]

Have you tried running with no filter inside the case? Do you have insite? what pressure is being reported in the fault code data? what about letting data monitor run and watching the pressure live? What about reported pressure sensor voltages - are they consistent with the pressure readings or are they high/low/erratic?

Don't know what troubleshooting steps you've already taken, beyond changing the sensor and filter, but I'd want to rule out legit excessive crankcase pressure before looking to other things, such as wiring.

Also, if you could provide some additional info, such as truck make/model, year, which engine (870/871/2250/2350/x15), miles, hours, has it been rebuilt before? dpf/emissions systems intact? Any programming done to the ecm? And anything else that might affect engine operation or the electrical system.