Fuel Gauge W212 E220 CDI Blue Eff 2010

[Benzwalah]

Hi Folks

Anyone out there who could tell me what might be wrong .? I filled up with Diesel and the Gauge shows 3/4 full. The dash functions tell me ive got over 400 miles to go before empty which is about right for my mixed town / motorway driving.

Any suggestions would be most welcome

Thanks