ECM fault code 711A- internal fault. what does it affect? Does it control trany?

In Volvo dealership all thay say is that you need a new tranny for 15,000. Which is B.S. The tranny was rebuilt recently including valve body. I am troubling to understand could that be ECM at fault? My Volvo Vida diagnostic program only show one fault 711A, which is internal fault in ECM, but I had this fault for 2 years and car was running and gears were shifting until one day it stopped. Then I rebuilt tranny again and now I can't make it work