Fuel Heating

Fuel Heating

The fuel heating unit is integrated in the fuel filter and is activated depending on the temperature and pressure in the fuel filter. Pressure switches and thermostats are also integrated in the fuel filter. The fuel heater only works with the ignition switched on.

The fuel heater is switched on in the case of:
- Fuel pressure greater than 6 bar AND
- Fuel temperature less than 2 °C

The fuel heater is switched off again in the case of:
- Fuel pressure less than 5.5 bar for a duration of greater than 5 min OR
- Fuel temperature greater than 12 °C OR
- During the starting process: if the electronics in the fuel filter detect a battery voltage less than 7.5 V for longer than 0.2 s

Troubleshooting
The fuel heater is not activated by the DDE control unit. However, the fuel heater reports a detected filter blockage via the signal DIAG_DKH to the DDE control unit. The DDE control unit then stores the fault.