C5 X7 3.0 HDi – Fuel gauge dropped to empty, range shows "- - -" (rain ?)

[marsalek]

Hi everyone,

yesterday evening I encountered an issue with my Citroën C5 III (X7) 3.0 HDi V6. Mybe it has something to do with that it was while/after driving in heavy rain.

Suddenly, the fuel level gauge dropped completely to zero (empty), and the remaining range on the trip computer shows three dashes ---. Crucially, the low fuel warning light (fuel reserve lamp) did NOT turn on.

Since the warning light didn't illuminate, it seems the BSI lost the fuel sender signal entirely (open circuit / out-of-range resistance) rather than registering an actual empty tank.

Given that it happened during heavy rain, I suspect water ingress into an exposed connector or wiring loom underneath the car (or around the Eolys/additive tank area or fuel pump/sender unit).

Has anyone experienced a similar issue? Which specific connectors or wiring harnesses on the underbody are most prone to water ingress and causing this fuel sender signal drop?

Thanks for any tips!
Karel

Edit 2026-10-18 12:05
We love the French cars for their spontaneousity!
The spontaneous healing was observed over the last night. The gauge is working nominally again. Very probably a water ingress issue.

[mickthemaverick]

What year is the car?

[marsalek]

Mick, it is end of 2013, one of the last C5 X7...

[mickthemaverick]

Sadly then my backup info cannot help. I only have up to 2012 cars. Hopefully another member will be able to help. Good luck