One assumes your car has the AL4 gearbox.
Look for an automatic transmission repair shop that has the Clip software and repairs French transmissions like the AL4. With a bit of luck it will only need a fluid change and a reset. If it needs the two EMV valves it should be appx £500 where they will change the fluid and do the reset anyway so the fluid will last another 32,000 miles. With any Renault/Citroen /Peugeot you need to look up the forums for your car and go onto YouTube and check out videos on problems with your make and model. You will lean a lot !
One forum:
https://www.honestjohn.co.uk/forum/post/index.htm?t=84272
Another
https://www.thepeugeotforums.com/threads/big-problems-with-206-automatic-transmission.332/
More out there waiting for your search
Hffhy, April 2022
