my automatic tranmission want shift from 2 to 3 why?

Looks like you are having an issue with a shift solenoid or the wiring. Could be a control module but not likely. This will require further testing to be sure but if the trans fluid looks good and there is no metal it could just be a solenoid. I prefer to do them all once I'm in there especially if you want to keep the car a while longer. Alex