F48 X1 Fuel pressure sensor malfunction resulting in flooded DDE

[hansi06]

I bought a 2017 X1 F48 xdrive 20d a few months ago. Last week, I sent the car in for its final service under motorplan and they found that the fuel pressure sensor in common rail was defective and caused diesel flooding of the DDE control unit. Apparently it's a big job and requires replacing of the DDE, the wiring harness and the fuel pressure sensor.

I'm not very knowledgeable about mechanical issues, so I want to ask, how does a fuel pressure sensor malfunction cause flooding of a major electronic component?

 

[Spanky]

Seems the fuel made its way up the harness, within the shroud, and into the DME. Pushed down the line with the pressure provided by the LPFP. Not unthinkable.

How the fuel slipped past the sensor itself and into the harness is another question. Could be as a result of bad design with no fail-safe, or just bad luck.

 

[hansi06]

Hopefully they updated the design! If it occurred 2 months later than it did, it would have been a costly repair

 

[Spanky]

Lucky indeed. Good on your dealership finding it as well. Seemingly it hadn't become problematic by the time of service?

 

[hansi06]

Yep, I had no problems/symptoms