I have a 2010 colbalt and some times it doesn't want to shift into overdrive. Also sometimes in first gear from a stop it is is a little slow to catch in gear. It is and auto and has190000 miles on it. I took it to a place to see what was wrong there are no codes that can be read besides the tank pressure switch witch has a bad wire. They told me the trans is bad and not worth replacing. Any help would be greatly appreciated.