auctionannie

My 06 has 175k miles. The tranny has been acting funny. Feels like it is trying to upshift as I am driving. A few days ago the wrench lite came on and it was constantly trying to upshift. Garaged it for a few days and when I went to take it to the tranny shop lite was out and it drove perfectly. So no I know its not the tranny it's self, any ideas on what sensor or relay It might be??