Intermittent Parking Sensor Issue

[Twosted]

Hello guys.

I have a question regarding the reverse parking sensor on my 2011 focus. It's the facelift model, so MK2.5 I assume.

Recently, putting the car into reverse has started prompting a single, long beep. The reverse light still comes on, but obviously I am not particularly trusting the reverse sensor as it currently stands.

Is this likely to be an issue with the sensor itself, or something else? Also, if it does happen to be the sensor, how easy are they to replace? 

Thanks for the help!

[TomsFocus]

There are 4 sensors in the rear bumper.  They are fairly easy to replace but cost around £30 each as they are colour matched to the car. 

Could also be caused by a faulty control module or damp/corroded wiring or plugs so needs further investigation.  When the sensors are working, leave the ignition on (engine off) in reverse and wave your hand past each sensor.  They should all beep individually.  If none of them beep, try listening very close to the sensors themselves as they produce a quiet clicking noise when working correctly.

[unofix]

Parking sensor "Beep Codes"

On 2/6/2024 at 12:31 PM, iantt said:

 

[Twosted]

It's a single, three~ second beep which stops and doesn't re-occur, often doesn't re-occur the same day. I'd assume that's the top one, whatever that may mean?