When the parking sensors are turned on manually or by shifting into reverse, a long loud beeeeeeeep comes from the dashboard, and the light on the parking sensor button flashes continuously.

I have checked that the sensors are 'pinging' by placing my ear against them and I can hear all 8 (4 front, 4 rear).

I have not been able to find the specific location of the parking sensor fuse anywhere online, so I had a look at all the fuses as best I could without removing them and they all seem fine.

Short of removing them, I've also cleaned them, tapped on them, and pushed on the back of them, but to no avail.

Any help identifying the cause or suggesting other tests would be greatly appreciated!

Cheers!