GF07.16-P-2006IJ CDI Fuel Supply, Function

GF07.16-P-2006IJ CDI Fuel Supply, Function

Component Identification:

The fuel supply (fuel low-pressure circuit) provides a sufficient quantity of filtered fuel to the injection system under all operating conditions and at an adequate pressure.

The fuel is held in the fuel tank.
The swirl pot prevents the fuel pump drawing in air when cornering with a low level of fuel in the fuel tank. On model 211 the housing o the fuel feed module serves as the swirl pot.

Fuel feed
The fuel pump draws the fuel from the swirl pot through the fuel strainer. The fuel pump then pumps the drawn in fuel to the fuel filter.
In the fuel filter, contaminants are removed from the fuel and the fuel is then pumped on to the high-pressure pump.
In the high-pressure pump, the fuel pressure is limited to approx. 4.5 to 6.0 bar by the fuel overflow valve.

Fuel return flow
The leak fuel from the fuel injectors, the lubricating fuel from the high-pressure pump and the reduced fuel from the pressure regulator valve and the high-pressure pump returns to the fuel tank via the fuel return.
The returned fuel serves:

^ For model 211
both suction jet pump in the fuel tank.
Via the suction jet pumps in the fuel feed module, the swirl top (when fill level of fuel tank is low) is also filled with fuel from the fuel tank.
The suction jet pump in the left fuel tank chamber allows its emptying.

^ For model 220
the suction jet pump in the fuel feed module, which also fills the swirl top (when fill level of fuel tank is low) with fuel from the fuel tank.

Fuel pump actuation
The fuel pump is actuated by the CDI control unit (N3/9) via the fuel pump relay (N10/2kA for model 211 or K40/5kT for model 220).

in case of model 211.026 (United States of America)
The fuel filter water level sensor detects the water content in the fuel filter and transmits a corresponding voltage signal to the CDI control unit. If the water level in the fuel filter has increased then the CDI control unit sends a message over the CAN data bus to the instrument cluster (A1).

Overheating protection for fuel tank
The fuel temperature sensor detects the temperature of the fuel delivered from the fuel tank in the high-pressure pump flange.
The rail pressure is lowered for an excessively high fuel temperature via the quantity control valve in order to protect the fuel tank from overheating from returned fuel.