Peugeot 206 auto gear lights on dash flashing

Hi bought a 206 with the same problem,exactly as you discribe, you have a counter on your car and its to do with the service,you car is going into limp mode your snow and sports light flash and you car pulls away in theard gear ,its desined to get you home, it neads a fluid change and reseting on the diognostic back to zero then the car will be fine,should then last you a few years, I cant remember its between 30.000 miles 60.000 not sure but I know its no less yes as you said when it starts to flash the car runs slow,and if you stop and switch of it stops flashing, we had to sit with the engine running untill warm then swith of and restart before we could drive ,(untill we were told at a gearbox expert in liverpool after he reset the counter with his laptop (after an auto fluid change ),good luck hope this helps cost us £80