I have a mk4 Mondeo and the parking sensors have stopped working. When I put the car in reverse I get a loud long bleep, and that's it. The sensors are not working at all on the front and rear. Any clue as to what the issue is and how to rectify it, would be really appreciated. Regards Simon

I have the same niggle at the moment someone I know at my local dealers put it on the laptop but had no fault code showing as it was intermittent but now it happens every time he will re test it again and hopefully it will show a fault code this time and say which sensor is in fault. Only got eight sensors to choose from.

My front sensors just keep beeping even when nothing there 

Mine were doing the same, more intermittent on the rear sensors.

It's daft how a rough wipe down with something dry made it better. they're a simple thing, all they do is push out a pulse and wait for it to be bounced back, if they're dirty because something stubborn is on them (like turtle wax etc. that was my issue) then they just reflect off the crap that's dried on them and you don't get any feedback for distance.

If not, I think you can unhook them individually in Mondeo's. Go through the chain, unplug them and find your faulty one, they work in a circuit. 

I had a diagnostics test done on my car actually during a DPF regeneration process £195. The chap told me it was the inside off side which was faulty. I changed that, and nothing. I have now changed the one next to it to match the correct shiny black colour. Still nothing is working. It makes a long beep when the car goes in reverse, goes off then nothing at all. No idea where to go now?

The fault on my parking aid was found to be the rear sensors speaker it cost £12 to fix.

On 4/23/2017 at 6:06 AM, Kawasaki kid said:

The fault on my parking aid was found to be the rear sensors speaker it cost £12 to fix.

Do you know where the rear speaker is located? Thank you

Sorry about the delay in responding, my sensor was in the roof behind the headliner accessed by removing the removing the rear interior light.

I have had parking sensors fail recently too. Single tone for 3 seconds when put in to reverse or parking aid button pushed then nothing.  After reading forums with no clear answer I went to an independent Ford specialist. They plugged Ford diagnostics into the OBD socket and it showed a faulty sensor on outside rear. One faulty sensor takes whole system out as all of them form a pattern of what it behind or in front of you. Ordered a new sensor at £54 from Ford and swapped it. Fault cured. All sensors are the same and come in Matt black. The corner ones are painted after receipt and the shaped bezel around them on the corner is not part of the sensor so stays in bumper. You can buy pattern sensor on eBay for £13 (Jan 2023). If no diagnostics done swap out sensor one by one until you find which fixes the fault. Before the fix the front sensors did vibrate when reverse selected, the rear ones did not so it was on rear circuit. When in doubt ask a specialist instead of spending weeks guessing. You could reverse into something in the interim.