Rover 75 Con Se CDTi Mk2 Tourer - Reverse parking sensors not working

[George2011]

Please can someone offer advise as my reverse parking sensors are driving me mad. I am a new member and have followed lots of advise from other threads on the same topic, but with no success.

My mk2 tourer has factory fitted reverse parking sensors which worked when I bought the car last summer. A few months ago they started working intermittently - sometimes fine and other times the dreaded 5 second beep. Now all I get is the 5 second beep. So from other threads I have done the following:

1. Checked each sensor for clicking - none of them click
2. Removed rear bumper and checked wiring assemblies and connections - they all seem fine, including the taped up assembly where the four black earth connections are joined together.
3. Checked the parking aid control box located above the drivers side wheel in the boot. I thought I had found the problem because the black connector, when removed was in a shocking state with water damage. So I replaced the control box and the black connector, checked the wiring to the connector 6 times but no - I still get the 5 second "system screwed" beep.

So I am at the point now where I am contemplating disconnecting it altogether but would really appreciate any advice. Have I missed something?

Thanks for any help you give