Reversing sensor problem
 

The reversing sensors on my cmax have started to make a constant pitch when reverse is selected no matter how far away anything is. I just used them in town in the car park and all was well the usual intermittent beeping as you get close to anything, but 8 miles later reversing into the drive as soon as reverse was selected the noise wont stop. Its the constant pitch when you are about 12 inches away. I've washed the muck off them and put my ear next to each one and can hear a quite fast ticking noise which I believe is normal.
Anyone got any idea's

had exactly the same problem on my Saab. Put up with problem for ages and then couldn't take anymore! Try drying them out with a hairdryer and lubricating the joints as moisture/poor contacts could be the problem.
If that doesn't work then i suspect one of the sensors is faulty (which is most likely if they are all clicking) I got a £20 replacement on flebay. Just swap them with the new one, one at a time, until you find the culprit.

Thanks for that. Are they a simple push out from behind and unclip job.

The sensors are supposed to click, thats how they work, they emit a sound and pick it back up, much like a bat.
Sometimes the loom will get damaged and have a broken wire, if there original fit then ids fords diag tool will give the user which sensor or circuit is not working.
Yes buying a sensor and taking pot luck might find the fix, then it may not.
Saab = gm = not ford lol

I have a similar problem occasionally on my Espace, and it came down to dirt on one of the sensors.

It was on mine - might be worth checking the Ford forums but it shouldn't be a difficult DIY job. The Ford ones may be different and the problem could be due to and issue with the wiring loom, but its mostly the sensors that go first as they are more exposed.

Saab use the same system (Park Assist) as fitted to the Volvo and BMW (not GM lol), not sure about Ford but I can't see the operating principles being much different.

I got lucky. They were held in by 2 lugs on the back. Pushed them apart and push the sensors into the bumper and dangled them down to inspect. No corrosion on the pins or nicks in wires so I reassembled them and tried them and they are back to normal.

Saab equals owned by gm, ford owned by ford.....lol