Paul,

Maybe this will help....it's taken from Vadis:

"Electrical fuel pump (FP)
Supplies fuel to the low-pressure pump:

-80 seconds each time the ignition key is turned to position II. When the key is turned to position III the pump runs until the engine is started
-under high loads.

The engine control module (ECM) sends a request to the central electronic module to start the pump.
Fuel is transferred using the ejector principle from the left-hand fuel pocket to the right-hand pocket depending on the amount of fuel in the right-hand gallery.

-The fuel level sensor in the right-hand fuel gallery transmits data to the rear electrical module about the amount of fuel. The rear electrical module transmits a CAN signal on the network which is retrieved by the central electronic module
-The central electronic module activates the fuel pump (FP) relay when the level in the right-hand gallery falls below 13 litres and deactivates the relay at 21 litres. If the signal for the amount of fuel is missing, the central electronic module activates the fuel pump (FP) to guarantee the fuel level
-There are two valves integrated in the fuel pump (FP). There is a check valve, whose task is to prevent the low-pressure fuel pump (FP) from drawing fuel through the electrical fuel pump (FP). There is also a pressure limiting valve in the fuel pump (FP) which limits the pressure to approximately 300 kPa absolute pressure in the supply line to the filter
-The operating pressure of the fuel pump (FP) is approximately 200 kPa absolute pressure

Low and High pressure pumps (all in the same unit)
The low-pressure fuel pump (FP) retrieves fuel from the tank and supplies the rest of the pump with fuel.
The high-pressure fuel pump (FP) supplies the fuel rail with fuel at variable pressure."


Sounds like it transfers fuel from one side of the tank to the other. When you look in either Driver Information Module or Central Electronic Module live data you can see the two levels displayed.

Also, looking at the DTCs there is no official Volvo DTC that matches the "P0094 Fuel system leak" your scan tools retrieved. It would be interesting to see what the correct Volvo DTC would be saying using an MTPro, Vadis/Vida, etc.

HTH

Sean