2009 A4 TSI

[Nick Lawrence]

Hello,
I moved up about 2 decades in Audi technology and am getting a 2009 A4 
Avant TSI.   I would like to know If there are knock sensors (most 
likely), and how they function.
Meaning if there is knock does the computer make changes and if it 
continues to knock create a stored code?
Is there ever any driver visible indicator that there is engine knock?
Any insight will be appreciated.
Nick   central Ohio