Sanyo P04 Fault

Hi Everyone,
I have a problem with a Sanyo VRF System, Master & Sub, both are SPW-904GDZH8B, the fault is on the Sub unit P04 fault (high pressure), the Master unit runs fine if l unwire it, l have linked out HP switches & tried 2 different main PCB's, checked pressure sensor readings via R/C, contacted Panasonic who suggested changing noise filter but still the same, has anyone seen this fault before, getting to the stage where l think l should tip it off the roof :cool:

Regards,

Skilts.