With the help of this forum, I was able to get my car running again.
I removed the valve body, stripped and cleaned every component, replaced the conductor plate and the electric plug connector.
I then changed the filter and added 6,5l of new ATF. I drove for 50km, and then stopped at a dealer to check the fluid level. They topped off the system with no more than 250ml of ATF and sent me on my way.
The car is running as good as new. Thank you to all that contributed with advice, and links. It is very much apreciated. I am happy to assist anyone who experiences the same problem.:thumbsup: