B6 Estate parking sensors

[Dazzzzzz64]

Hi. I have a 2009 b6 est right hand drive with factory fitted front and rear sensors. My battery was on it's way out before lockdown and failed completely a few weeks later. Replaced the battery and everything fine but now the sensors don't work at all. Just a long beep for a few seconds and then the button just flashes. Cant hear any noise from the sensors. Module failed maybe? The fuse is ok. Where do I locate module?