you can shut the high pressure pump for the fsi to lower the pressure so you can work on the the fuel system without hurting yourself. as soon the the key is cycled again the pump turns back on. the car cannot run off regular fuel pressure.

 

The mode im talking about is there to relieve the increase fuel pressure in the fsi, but the car does run on the lower fuel pressure. Its also true that once the key is cycled the high pressure pump will run again. Thats why i suggested asking a chip burning coming to see what kind of results they could get by permantly disabling the system.