Presupply Pressure Sensor DDE 4.0

The presupply pressure sensor registers the absolute pressure (presupply pressure and atmospheric pressure together) in the fuel feed after the fuel filter and serves the purpose of monitoring the fuel supply.

The presupply pressure sensor is integrated in the fuel filter housing. The DDE control unit supplies the sensor with ground (M_KND) and a supply voltage of 5 V (U_KND). The sensor sends a corresponding measurement voltage (EA_KND) to the DDE control unit.

Presupply Pressure Sensor Monitoring

Troubleshooting

Fault code 1255 "Presupply pressure sensor" is stored if the presupply pressure has electrical defect.

Consequences:

• 4 bar is output as a substitute value
  

Presupply Pressure Monitoring

The presupply pressure is monitored during engine start and engine operation by way of setpoint/actual value comparison. Fault code 1260 "Presupply pressure monitoring" is stored if the DDE determines an impermissible deviation in the presupply pressure from the setpoint.

Consequences:

• Depending on the deviation, the injection volume is reduced or the engine turned off or engine start is not possible.