Parktronic not working at rear - 2008 E220 CDi

[JohnD25]

Hi all, advice or help required please.

When I put the car in reverse the system buzzer sounds for a couple of seconds and the 4 central red lights come on. The sensors don't then work just the reds stay on.
The front ones are working fine.

On previous cars I've been able to tell by the "clicking" noise when putting a finger near the sensor which one isn't working but no such luck with this car. I haven't been able to get underneath to disconnect them and clean the connectors. Is this likely to help if I do it or not.

Any ideas appreciated.

Thanks

 

[mioba]

Doubt cleaning the connectors will do anything, it worth it as you need get in there anyway.

You will need a code reader to id which sensor is out. They are cheap and just a clip in and plug.

Biggest pain is aceesability, depending on the car.

 

[JohnD25]

Doubt cleaning the connectors will do anything, it worth it as you need get in there anyway.

You will need a code reader to id which sensor is out. They are cheap and just a clip in and plug.

Biggest pain is aceesability, depending on the car.

I have a code reader so I'll give it a go. I've stuck my head under the rear bumper and can see each of the sensors and their connectors so they should be ok to get at.
Thanks