The DDE 5.0 features two presupply pumps. One pump is located in the fuel tank while the other presupply pump is located on the vehicle floor in the fuel supply system. Both pumps are switched on and off by means of a relay and deliver the fuel via the fuel filter to the high pressure pump.
The engine continues to run in the event of the in-tank pump failing, however, this is not the case if the in-line pump fails.
The relay and relay activation are monitored but not the pumps themselves. In the event of a fault, the following fault codes may be stored: