I was driving down the highway this morning, when my automatic transmission oil temperature light came on. I was doing between 110-120 km/h. shortly after that a loss of power and lots of white smoke billowing out the back. pulled over to the shoulder, got out and noticed a huge oil slick behind me. looked underneath and there was oil pooling under the engine. all the other indicators- oil pressure, engine temperature, etc. were all in the normal range. the only thing that was not mormal was the automatic transmission oil temperature light indicator on. What could it be? something major or something minor?