Help with P0AA6 / 613

Last month, i got an 06 Prius with 244K miles, vehicle was badly used and not well maintained. Drove it for a bit for a day or so and got the red triangle. When i scanned it, i got P0AA6 subcode 613 and i noticed that the ICE was louder than normal, so I went ahead to drain the transaxle oil. When the drain plug came out, it had a tiny bit of metal like paste which was not a good sign and the oil was really dark. It really appears for a fact that the wrong type of transaxle oil was used in the car. I went ahead and filled it with ATF WS and the code went away. I drove for more 100 miles and there was no code but the ICE was still a bit louder than normal. A friend subsequently took the car and after another 150 miles had the red triangle. This morning when i got to the car, the computer had been reset, as the 12v battery had drained and he had to use another 12V battery to get the car ready. The car drove fine except for the AC which no longer works - can't say if its related as it was working before the red triangle.
Suspecting that a transaxle failure may have led to the red triangle (car was not scanned before the 12V battery got drained), I went on to perform a megger test to ascertain the status of the MG2 stator coil and all three phases returned with high resistance values. Is it possible that changing the transaxle oil can correct the P0AA6 / 613 DTC long term or is it just a temporary fix leading ultimately to a transaxle change? Would really appreciate some direction from the senior members here.

 

I had another buddy of mine come in today, we went ahead and changed the MG2 Stator as i had another Prius transaxle around. Well, so far so good there has not been any codes, and the noise from the ICE starts is a lot quieter than it was before. I am being positive but will only know after i have put some more mileage on the car. We did not know exactly what to expect while making the change but referenced quite a number of youtube videos including the "MG2 Stator Replacement" video from LG. One area that we had some difficulty was in lowering the transaxle down enough for the removal of the MG2 Stator. We found a couple of bolts underneath the car that did just that. When the Stator came out, we inspected right round the coil to see if there were any visible signs where the Stator got burned but did not see anything.
After the change, i drove the car for about 20 miles while monitoring the INVERT TEMP-MG1 and INVERT TEMP-MG2 which peaked at 102 F and 106 F respectively.