a4 tdi 2001-2004 instument cluster/clocks are you the one who can help???????

my original cluster works fine,well-except the fuel gauge.
stopped working all of a sudden,its definatley the clocks as i've tried another set plugged in and fuel gauge works! only thing is the second hand set i have are same in every way,even same part number but i've been told the data is set in different places because the changed this in 2002 and my original clocks are 2001 is there any way to wipe clear and re-store data in correct order???
or does anyone know why fuel gauge dont work anymore?
better still which chip in the cluster is stopping my fuel gauge from working? as i've got 2 clusters i can change the chips around.