parktronic not working anymore?

[C230komp]

When I turn it on it just beeps constantly and doesn't give any readings anymore?
any ideas on this?

 

[Silver CL55]

Mmmmm..... mine has just started this too, button light stays on.

 

[Davo]

Check one of the sensors hasn't come adrift behind the bumper. One of mine is loose, when it strays to far I have to turn the Parktronic off, as it goes nuts at traffic lights.

 

[developer]

On my previous E320 CDI the rears behind the wheels would fail due to water ingress caused by the constant road muck thrown at them.
When one goes the whole system goes haywire.

STAR is the best way to diagnose.