My 2010 equinox transmission is kicking down during standard or even light excelleration and while just trying to maintain speed. Also if I am excelledating heavy from a start it will sometimes lock into second gear and I have to either restart the car or sometimes I can shift into manual and slow down to left it shift into first and then manually shift past second then move back to auto mode. Could the kick down issue be the throttle position sensor? It just got a cel but it is for o2 preheat. No codes for anything else. I have 75k mile currently and I drive lots of hwy miles. ?????