Parking sensors (argh!)

Sorry, another parking sensor post!!
But there is a reason for it
’ve replaced all the sensors in the rear bumper last summer and all has been well.
Just been driving around the last few weeks and noticed that they do not appear to be working, i’m not getting a long beep like I did before to indicate a faulty sensor and none of them are clicking at all which seems odd because I could handle one sensor failing but for all four to go at once!?, does anybody think it might be the ECU or have any ideas what I could look at to eliminate any of the componant parts indavidually?

Thanks for any help.

Colin.

Has the speaker failed? Does the light flash on the switch?

Hi TD4van,
Yes the light on the switch illuminates and the speaker works as it gives the normal audible beep when reverse is engaged.
Everything appears normal but I’ve got no clicking from the sensors or any indication of a fault, I did wonder if it could be the ECU but would it work at all if it was that?

Thanks

Colin

Hi Colin - strange one as it sounds as if it’s happy and not seeing any faults within its circuits.

However, have you checked the bumper harness for chafing/wire damage - ideally using a multimeter to check for voltages etc. It might not be getting the signal back from the sensors but the earth/ground is good so it doesn’t flag a fault with the sensors

Sounds like an idea!
I’ve ended up ordering a couple of new sensors (£35 for some Land rover ones) so would need to take the bumper off to swap these out, but before I do I’ll do as you suggest and stick my multimeter on and check the harness.
Is this common issue for the wiring harness, any typical areas where it may be chafing that I should look at?

Many Thanks.

Colin

Check where wiring runs across bumper by armature and where it comes through body

Well, had the bumper off yesturday and checked the wiring harness to it’s connector and then checked from there back to the ecu and all wires have good continuity, attached a brand new sensor and this did not work either. Best bit was when turning everything back on after plugging it all back in the ecu threw up the fault alarm .
So job today is to attach the scan gauge and see if i’ve got any faults I can reset, I think i’ll end up swapping the ecu anyway.

So new ECU arrived so managed to fit fairly easily but that did not work, no fault sound though! Just back to normal, no clicking on the sensors and no fault detected in the system, all sensors replace last year and unlikely to have all gone at once, even new ones don’t work.
Any ideas out there?, please!
Might have to bite the bullet and take it to a garage or dealer to take a look at.

Is it a FL1? This has no diagnostic capability for the PDC system so it’s diagnosis by wiring checks, resistance checks on sensors and parts substitution

Did you replace all 4 sensors recently?

Yeah FL1, had the scanner on at the weekend and found that out too, was worth checking anyway just in case
All four replaced in July last year, bought some genuine LR ones and tried them at the weekend with no result either.
Oh well, had a good try
Thanks for your help.