Citroen C5 reversing radar

[tapkaJohnD]

I posted a request for help on this before, and learnt to my suprise that these sensors chirp!

Listening wasn't straight forward, as the system will only engage when the engine is running, and an assistant is needed to hold down the clutch while you listen. My high-tone deafness made it hard to hear, but with the help of Daughter and a mechanic's stethoscope, it was clear that one of the four wasn't chirping. I've replaced it, at little cost (£12) in comparison to the labour charge at a dealer, but Alack! It has not cured the problem.

The other sensors do chirp, but not the same, some quieter than others. Is it worth replacing them all, still at less cost than at a dealer? Or should I look elsewhere for the fault?

Thanks,
John

PS WHY do they chirp??

[GreenV8S]

If you suspect a sensor fault, I would try swapping the sensors around to see whether that fault is associated with the sensor, or the wiring to it.

[tapkaJohnD]

Thank you, GreenV8!

Have a spare in my hand - the old one - but as that didn't chirp, it might be best to chuck it anyway. Can't check if the new one chirps, as Daughter lives some way away. Maybe a neighbour will help!

Cheers,
John

[GreenV8S]

Can you find a graphic equaliser or sound spectrum analyser app for your phone?

[tapkaJohnD]

What? Please tell how that will help?

[GreenV8S]

It would display the range of tones it can hear, which will include the higher frequency chirps which are outside your own hearing range..

[tapkaJohnD]

Um! OK, thanks!

[tapkaJohnD]

Got to check the new sensor eventually, and that doesn't chirp either. So as suggested I swapped it around. and it doesn't chirp in a new position, while the OE one I've moved does, and the whole system still doesn't work. I needed help, and took it to my independant garage. They checked by doing the same, and that the sensor itself worked. They quizzed me - where had I got the sensor, Citroen? Er, no - it was £19, off ebay. Hmmmmmmmmm!
They could do two things for me

A/ Fit an aftermarket sensor system that used the same sensors, but had a read-out box stuck to the dash. No, not really.
B/ Order a CITROEN sensor and fit that. OK! And it works, but one sensor costs ONE HUNDRED and nineteen pounds.

Apparently these sensors are used by many manufacturers, but each has them tweaked so that they only work on their cars. And then charge a grossly profiteering price for an item that costs pennies. Grrrrrrrrrrrrrrrrrrrrrrrrrrrr!

John