Fuel Pump (6/31) [2018-2020 | 2021-2022, B4204T18 | 2021-2022, B4204T47]: Description

The fuel pump provides fuel from the fuel tank to the high pressure fuel pump.

The fuel pump is controlled by the fuel pump module using a three-phase pulsed voltage signal. The fuel pump motor is brushless.

The internal components of the fuel pump are described below:

NOTE:

The exact design might differ. The figure only depicts the principal components.

Courtesy of VOLVO CARS CORPORATION

1	Electrical pump, check valve embedded in the end-cap of the pump. Opens at: 10 kPa (petrol and diesel engines). 50 kPa (vehicles with Twin Engines).
2	Fuel level sensor
3	Level arm
4	Float
5	Sock filter (petrol engine and XC90 Twin Engines, particle markets).
6	Reservoir contents: Pre-filter, electrical pump. Petrol engine has this located inside the life time filter housing. Diesel engine has this valve inside the pump end cap. Vehicles with Twin Engines have this valve located in the fuel tube between life time filter and flange. Umbrella valve. Releases fuel into the reservoir. Petrol engine has this located inside the life time filter housing. Diesel engine has this valve inside the pump end cap. Vehicles with Twin Engines have this valve located in the fuel tube between life time filter and flange. Ejector pump. Continuously fills the reservoir with fuel. The ejector pump is driven by the fuel pump flow. There is a small amount going through the ejector and back to the reservoir for petrol engine and vehicles with Twin Engines. For diesel engine the ejector pump is driven by the return flow. Petrol engine has this located inside the life time filter housing. Diesel engine has this valve inside the pump end cap. Vehicles with Twin Engines have this valve located in the fuel tube between life time filter and flange. Life time filter (petrol engine and vehicles with Twin Engines, clean markets). External filter (diesel engine and particle markets). Petrol engine has this located inside the life time filter housing. Diesel engine has this valve inside the pump end cap. Vehicles with Twin Engines have this valve located in the fuel tube between life time filter and flange. Over Pressure Relief Valve. Opens at pressures between 730 kPa and 950 kPa Petrol engine has this located inside the life time filter housing. Diesel engine has this valve inside the pump end cap. Vehicles with Twin Engines have this valve located in the fuel tube between life time filter and flange.
7	Electrical connector
8	Flange
9	Parking heater's connection
10	Feed flow to engine
11	Return flow (diesel engine). Return tube connection under the flange also contains a safety valve that does not allow fuel to be drained from the fuel tank.
12	Sucking Jet Pump. Enables transfer of fuel from passive to active side in a saddle tank through a transfer tube connected by a quick connector. NOTE: The transfer of fuel only works when the electrical pump is active.