Each time I select "reverse" I get a long tone from the detector speaker. I think maybe one of the detectors has failed or something, as I asked the wife to walk behind with the car in reverse and no sounds were produced, (no jokes, please, she is still with me !!). Does the tone point to anything specific or is it just a warning >

The module is on the vehicle network. The Reverse Park Aid should have DTCs logged for diagnosis. Probably a sensor in the rear bumper cover but the module knows for sure what DTC is logged.

I can 'feel' each sensor with my finger tips and tell whether it is 'clicking'. You have to touch them very softly to feel the 'click'.
The engine does NOT need to be running to test the sensors. (key-on-engine-off in reverse, park brake ON) Just move your fingertip very slowly and softly on each one and you can feel them click if they are functioning.

Sometimes they do not work after a bumper repaint because the paint was applied too thick. I have had to send a car back to the body shop after they put too much paint on the sensors and the system stopped working. (error tone!)

bob

I get the long beeeeeeeeeeep but very randomly.

When I had it just after I bought the car I had to replace two senors to solve the problem.

Thanks everybody. Looks like a visit to my local independent. I've also got a disc stuck in the CD player too. The jobs just mount up and up !!

Stupid me for not looking in my copy of the Technical Notes where it is all described on page 132, even telling you the tone length, (3 seconds)