Hi

>>>>Is this as a response to a possible fault condition or part of normal operation?<<<<<


Both I believe, I am not that familiar with the focus, but think it will have a IMV rather than a pressure regulator. So excess pressure in the rail( produced by error or after switch off) needs to be bleed off.

The high frequency pulse on the injector bleeds the pressure of via the leak off without opening the injector to cylinder.

You may get more help if you post the bigger picture of faults / tests / symptoms etc. I think.

I am sure Mark will advise on method of testing the IMV / pressure regulator If you take on board his comments.

cheers Aidan