VXOC Astra-J/GTC

Hello guys, 
i have every morning bad message "service vehicle soon".. after diag in car-service mr. say me that ist error at fuel temp sensor.. My car was in that service mayme half of year before and thet sensor was completely changed .. as gay said... bud now is the bad message back, with same error code.. any ideas ?

Surely the part is still covered by warranty if it was changed less than a year ago.

It would also pay to see if there is something else causing the issue.