TANK SYSTEM MALFUNCTION

[jazz]

Hi all I am new to this site last week upon reaching my work place I encountered a sign in my dash saying TANK SYSTEM MALFUNCTION CONTACT WORKSHOP. And the fuel gauge had dropped to the RED mark when I still had over 150 miles left in it I have a Audi A6 3.0 tdi se le mans edition 2010 saloon model i was confused by this and have had the car for 3 years now and it has been great. On doing some research on the fault have come to a conclusion that it has something to do with the fuel tank sender unit which is is situated behind the rear seats upon doing some further searching it happens to vehicles touching the 100,000 mark or over so i pulled out rear seats and banged on the surface of the fuel pump's then went to fill her up at the nearest gas station put in £50 diesel and hooray needle moved but the mileage clock display does not read how many milles I'm getting as before it did. has any body had or is having the same issue as i am if so can you please share so i can resolve this problem too thank you 

[WPAWS]

had a similar issue with my car post link below