Brief description of components
The direct injection system consists of the following components:
- Digital engine electronics DME (development status: MED 9.2.1/MED 9.2.2 engine electronics for direct injection)
The 2 DMEs actuate the respective cylinder bank of the engine.
- Electric fuel pump
The electric fuel pump supplies fuel to the two high-pressure pumps.
- Fuel filter with pressure regulator and leakage filter
The fuel filter with pressure regulator regulates the fuel pressure in the feed line.
- High-pressure pump
The 2 high-pressure pumps compress the fuel and feed it to the rails.
- Pressure damping vent valve
The pressure damping vent valve allows the fuel to flow back to the return line and ventilates the fuel pressure regulator.
- Return cut-off valve
The return cut-off valve prevents a loss of pressure in the injection system.
- Rail with pressure limiter valve
The 2 rails store the compressed fuel and distribute it to the high-pressure injectors.
- Rail pressure sensor
The 2 rail pressure sensors measure the current fuel pressure in the rails and report this to the DMEs.
- High-pressure injector
The high-pressure injectors inject the fuel at high pressure directly into the combustion chamber.
- HDEV control unit
The 2 HDEV control units actuate the high-pressure injectors.