Engine malfunction message suddenly appeared after filling with diesel. Thought that I had put the wrong fuel in but no it was actually diesel that went in

Stopped the C-max and when fired up again, the message reappeared

The engine was running as normal, and was wondering whether there is a sensor that could have been disturbed as we gone over a large speed bump earlier in the journey

Travelled back from Edinburgh to Notts with the message still there, but there was no lose of power or lose of fuel effiency

Does anyone know what it could be

The C-Max has done 80k in mileage