Hi,
Our FL2 2013 has decided to give a constant tone last time out when selecting reverse

Been trying to diagnose the cause today, so ignition on and reverse selected and started with a few quick bleeps then straight to the constant tone,
turned on and off with the dash switch a few times but still constant,
had a listen to All sensors and All of them are clicking
from the tone its the rears thats causing it, fronts are fine.
o/s/ outer, n/s/ inner and n/s/ outer unplugged and plugged back in (not got access to o/s/ inner yet) with no change
Unplugged and removed the o/s/ outer to clean it and get the part number tried the sensors without it connected but just get the flashing switch light and no noise showing it as a fault.
tried to split the main plug of rear sensor wiring loom to main loom but unable to split it as yet

Anyone able to suggest a solution please or what to try next

best value PDC on the bay is £10 but not convinced its a faulty sensor as all clicking so which to change

tried the "search" and get plenty of Not working but found no Constant tone threads

 .
my first ever FL2 and I did keep it longer than most other cars!
But its now gone way up Norf

I get a constant tone when it's been raining and water has got into the sensors.

Directing some silicon spray in there helps drive out any moisture. Also put some silicon grease in the connectors when I last had the bumper off.

Issue goes away for me when the moisture has dried out or driven out by silicon. Discovery 4 HSE - Aintree Green
Freelander 2 TD4 SE Automatic - Tonga Green
Defender XS - Tonga Green - Gone Now
Freelander 1 Td4 ES Manual - Epsom Green - Gone Now *
Freelander 1 Td4 Kalahari SE - Epsom Green - Gone Now
Freelander 1 XEi - Epsom Green - Gone Now

www.greenlandrover.uk

Yep, me too as above. Seems to be water-related, so it comes and goes with the weather! Occasionally constant tone when in reverse, but equally it is sometimes no tone at all! Adds a bit of spice to reversing in the rain! 2005 D3 2.7 Auto
Previously:
2010 MY FL2 TD4e GS - Now gone at 199,500 miles, about 135,000 of them mine.
‘93 Defender 110 200TDi CSW
‘87 Defender 90 4 cyl Petrol
‘83 110 CSW V8 - best ever!
Range Rover 2-door V8 (not sure of year - 4-speed box and vacuum diff switch)
Series III SWB Diesel

Same here when I had my FL2 and no different in my Evoque! Like the others, it stops when it dries out. Past: FL2 TD4 HSE Auto
Evoque SD4 Dynamic Lux Auto
Present: Audi A3 S Line.

Hi,
there getting a dose of WD40 to try that but its not exactly rained a lot this last week

any ideas how to work out which sensor it is, if it is that (other than only spraying 1 a week)

 .
my first ever FL2 and I did keep it longer than most other cars!
But its now gone way up Norf

Hi,
well Wd40 has not helped any

Bought a new sensor (£9) and have been trying it in each position, 3rd one I tried gave an intermittent tone and thought it was just near to the wall, but no went back to a constant tone again, tried last position and still got the issue.

Any more thoughts welcome  .
my first ever FL2 and I did keep it longer than most other cars!
But its now gone way up Norf

Next place I'd look is the big plug in the bumper that all the sensors connect to. Water can get in there as well

Same issue after it has been raining or sensors are dirty.