From your description of events where you lost drive this would lead me to expect a mechanical failure, if it were purely electronic control it would run in emergancy running and would just feel under powered because the correct ratio would be difficult to determine. the diagnosis route would be to check the fault memory of the gearbox nd engine electronics then take a sample of oil from the gearbox, any even small metallic objects would indicate a failure of some kind. Good luck.
__________________
|