Soo I have a manual cobalt coupe 2005. I was driving and after a red light going from 3rd to 4th it locked up on me and i cant get into any gear at all. I just did some electrical work on the car installing a new head unit and lights. I was wondering what the problem could be, does the car have a transmission lockout trigger that mightve been triggered? Or do i need tranmission fluid. Any input would be helpful.