just reversing on the drive and the parking sensors were making a weird beeping not the normal tone and didn't even flat line when i hit the mrs Mercedes ( oops ) any ideas ???

Could be one or more of a few causes, most likely place to start is faulty sensor, check if all are 'ticking'...could be internal short of a sensor, if no joy there check the wiring a few good read ups on here.If you have, or can get access to an IID tool or similar would certainly help pinpoint. Ive had both a faulty sensor (easy to find) internal short on one (not so easy) Good luck  D3 TDV6 SE auto 2006
FFRR TD6 vogue SE Overfinch 2006
RRS TDV6 HSE 2007
L322 4.4 TDV8 Overfinch 2012

thanks , just been out and started the car up put it in reverse and seems to be working fine now , god knows whats going on there. but thanks anyway

Wet weather is not nice to the sensors, also apparently jet washing does them no favours

I concur with Kernow. I have intermittent (annoying) fault with mine which manifests itself after driving in wet weather Robin
2008 Range Rover Sport TDV8
Gone:
Jaguar S-Type V8 4.2 Sport
MGZTT 190 2.5

You would think something like Rain would be factored into a parking sensor!

Some systems give an error tone if there is a problem when you first select reverse.

So if its a different tone, that could be it, and dn't rely on them

cheers for the info guys

Just for clarity, and in case it's of use, the parking aids on mine have 3 tones. High pitched bleep means front sensors give picked up something, a lower pitched bleep is the rears. If you get a continual high tone for about 10 seconds and then the parking aid switch light flashes, then that's telling you that they are not working.

Also I don't know what happens if, say, you are reversing towards a wall and at the same time the front is near, say, a hedge. Don't recall getting both tones on mine so one must have priority.  Robin
2008 Range Rover Sport TDV8
Gone:
Jaguar S-Type V8 4.2 Sport
MGZTT 190 2.5

I think you do get both tones on early cars.

If you have parked close to something nose in, and then need to reverse out you get both.

Macca wrote:

Could be one or more of a few causes, most likely place to start is faulty sensor, check if all are 'ticking'...could be internal short of a sensor, if no joy there check the wiring a few good read ups on here.If you have, or can get access to an IID tool or similar would certainly help pinpoint. Ive had both a faulty sensor (easy to find) internal short on one (not so easy) Good luck

A short would knock all of them out and incase of the fronts give an error on the dash.

problem statement, front always beeps regardless.
So i verified that they all make the clicking sound.
My guess is one of the sensors cables is shorted by water in the connnector.
I can with some dificulty get to the side sensors and unplug and replug them.
the middle two i have no idea. any help there would be nice.

water can also get into the sensors.

Options are

1) get an expensive fault code reader and see which one is reporting a problem/short distance

2) buy a replacement sensor, (can get them cheap in europe/china) (or even 2 if they haven't been working for a long time) and remove the bumper, and swap a new one out, one at a time and see if you can sort it.
As yours always has a problem, you stand a good chance

Last edited by Andy K on Thu May 11 2017 6:06pm. Edited 1 time in total

Got it, i will buy a sensor and proceed.
I just need to figure out how to get to the middle two, later.