Std pressure is 3 bar(43psi) with vac on, and around 3.6/7 bar(54psi)with vac off.
So long as the RR has a anylyser then just watch the gasses closely, it will be a big clue.
These things are one of the(many) reasons I don't bother with std ecu as well, you would be much better off using a "known" system that your RR can set up, it will pay dividends in the end.
tabetha