Hello,

I've recently purchased a complete OEM rear parking sensor system from a polo 9n3, would anyone have the wiring diagram for it?

First Welcome to the forum.

 

These are from the dealers wiring diagrams 

The Brown wire on pin 8 goes to a local ground point & the diagnostic "K" line you will need to T into that either at the Onboard supply control unit under the dash above the pedals or at the 16 pin diagnostic socket