Parktronic fault code A23400. Rear PARKTRONIC warning element 1 has a malfunction

[Mickp220]

Hi I have a C220 W204 estate AMG and recently had the Parktronic warnings of 4 red lights back and front. I got two faults one of which was a faulty sensor which has now sorted that but it still gives the warning and disables. The remaining fault is: Rear PARKTRONIC warning element 1 has a malfunction. The code reads A23400
I cant figure what or where this might be. I clear the faults and it works as expected all sensors working until I use the car and restart again and gives warning lights again. Any ideas out there?

 

[Mickp220]

Hi I have a C220 W204 estate AMG and recently had the Parktronic warnings of 4 red lights back and front. I got two faults one of which was a faulty sensor which has now sorted that but it still gives the warning and disables. The remaining fault is: Rear PARKTRONIC warning element 1 has a malfunction. The code reads A23400
I cant figure what or where this might be. I clear the faults and it works as expected all sensors working until I use the car and restart again and gives warning lights again. Any ideas out there?

This is in answer to my own post above. After biting the bullet I asked my local Mercedes dealer to diagnose the Parktronic problem and finally it was diagnosed as a fault in the rear headliner warning display. Probably they substituted a new unit and cured the fault. However at £250 for a new unit i paid for the labour only and sourced a fresh unit online for £20! Everything working great again.