Haven't you already made a thread on this? As said before, could be any of those things and you won't find out more until you start doing some diagnostic work, as in physically testing components. Have a look at the link in my sig nd see how you get on.
Pressure controller at stop says to me the fpr is jammed, that'd be where i'd start.
Pressure controller at stop says to me the fpr is jammed, that'd be where i'd start.