My park assist has been playing up. When engaging reverse(dsg) I get a continuous beep (not the short pip) that used to occur. The car display also no longer appears. One of the sensors was replaced 5/6 years ago. The fault began during the wet weather and initially would clear after a couple of days of dry weather, but is now permanently faulted. I am inclined to think the control module is on the blink but do not know where it is located. Any help much appreciated!

It's probably behind the left hand panel in the boot.

 

I'd suggest getting a scan done with VCDS or similar first rather than just replacing parts. It'll also help if you need to check the coding of a replacement module after fitting.

I had the same issue last time. 
 

It may be different on your car, but changing the Buzzer solved my issue. 

 

Ordered the one below and got my workshop to fit it. Best to scan for any faults using VCDS first though. 
 

SG$ 5.17  20％ Off | 8E0919279 Car OPS PDC Reversing Radar Parking Aid Warning Buzzer Alarm for VW Audi Skoda Seat
https://a.aliexpress.com/_BfgS3PXT