Unfortunately, there's no specific manual available for troubleshooting these faults at the moment. However, there's some good news: Rotax service centers and repair stations are actively training to better diagnose issues in the ECU.
To get help with your situation, I suggest reaching out to your local Rotax service center or repair station. Sharing your ECU data with them can assist in pinpointing and addressing the problems you're experiencing. Their specialized knowledge will be a great help in finding solutions.
Rotax Service center, repair stations, and Dealer locator are found here - https://dealerlocator.flyrotax.com/
Here is a video on how to download BUDS software to extract your ECU data - https://www.rotax-owner.com/en/videos-topmenu/free-videos/686
