Fuel tank access not locked

[jonnyashuk]

I have a Citroen c5 2008 1.6 tourer. Keep getting error on my dash saying the fuel access in not locked, is there a magnet in the fuel cap

[Stickyfinger]

Locks via dead lock on ignition on I think......the magnet in the cap is for the DPF injection
I have never seen that fault mentioned before, new to me that one.

[MikeT]

Quick google suggest magnets or break in sensor wiring loom. Pull of wheel liner to check wiring if the magnets are visible.

[jonnyashuk]

I have ruled out the sensor on the flap and the dpf fluid. The fault comes and goes but if I start the car with the cap off the fault comes up straight away so would suggest that there is something wrong with cap and there is a sensor in that somewhere?