hello i'm new to this site and i have skoda octavia 1.6fsi elegance and it has front and rear parking sensors unfortunately they doesn't work when i put it in reverse it makes the beep noise it shows on the screen for few seconds but then the R button just keeps flashing but sensors doesn't work anyone has any idea what could be wrong with it ? thanks  

Lots could be wrong; from a broken sensor or buzzer through to a broken wire in the loom.

Best bet is to get it scanned with VCDS and go from there.

Put your ear against each sensor with the sensors active and listen for a clicking noise. No noise from one sensor suggests that is where the fault lies. More than one may suggest a wiring issue.

Welcome davey, hope you get the issue sorted.