Loud clunking noise then Automatic Gearbox Failiure flashes up then dissapears

You need to get a diagnostic scan carried out to see what fault is .

Hi Nicola, did you get a fix for this? Our car had the same fault. We have been told it was some kind of valve failure in the gear box

I get this occasionaly and took it to a Citroen main dealer. They gave it a diagnostic, and the results showed no problem. Chief mechanic then told me that this is something that happens with a 2ltr engine. If the engine is stil cold-ish the hydrolics (or air valve or something similar) tend caause this problem. (I didn't catch exactly what he meant as it is all Klingon to me) I think he is right though, because I drive it with extra care while accelerating for the first mile, and once it is warmed, it is perfectly ok.
They told me there was nothing to worry about.