Fuel Tank: Description and Operation

Fuel Supply, Low-pressure Side







ReturnLess Fuel System - RLFS

Consisting of:
- 1 demand-controlled electric fuel pump
- Fuel filter (lifetime filter in the tank)
- Fuel-pressure regulator (fuel pressure approx. 83 psi/5.7 bar max.)

The low-pressure side of the fuel supply system consists of a returnless fuel system (RLFS - ReturnLess Fuel System). The variable-speed electric fuel pump delivers the fuel via the fuel filter and fuel-pressure regulator (in the fuel tank) to the quantity control valve on the high-pressure pump with a max. pressure of approx. 83 psi (5.7 bar). The sucking jet pumps in the fuel tank are also operated with the low-pressure side.

The two fuel-level sensors are installed in the fuel tank for measurement of the fuel level.


Internal design of the fuel tank










NOTE: The procedures for checking the fuel pressure, holding pressure and delivery rate of the electric fuel pump are described in the PIWIS information system. Observe the relevant safety instructions when working on the fuel system.

Tank ventilation

The fuel tank is aerated and vented exclusively via the active carbon filter, which acts as an intermediate storage device for any HC emissions. Regeneration of the active carbon filter takes place via the tank vent valve when the engine is running. The active carbon filter is installed behind the wheel housing liner at the rear right. When the engine is running, the system is vented via the electric tank vent valve (in the engine compartment) to the intake system of the engine.