1 Connection to the fuel tank
2 Fuel additive pump
3 Piezo sensor
The fuel additive pump is designed as a displacement-type pump (piston pump). It feeds the fuel additive, metered according to the command issued by the fuel additive control unit, via a short fuel pipe to the injector where it is injected into the fuel tank.
The piezo sensor at the bottom end of the fuel additive pump unit contains two sensor elements with the following functions:
โข They determine changes in the viscosity of the fuel additive as a result of changes in ambient temperature.
โข They detect when the fuel additive tank is empty (measurement of the precise fuel level in the fuel additive tank is also envisaged and will be implemented at a later date).
In the event of an empty fuel additive tank, initially the engine system fault warning lamp illuminates. This means that from this point, only a residual quantity of fuel additive is available for approximately 250 liters of fuel. If the fuel additive tank is not refilled, the MIL illuminates and the fuel additive injection process is stopped.