Purchased a car a week ago. It ran fine. It has a auto transmission. Yesterday, drove it for 15 min and while turning it will not go into any gear. Looks like it's stuck in neutral. Ran the codes and it came up with 55. Which means all is well. The engine starts fine but it does not move the car. How do I diagnose this? Is it the transmission? Shouldn't I get a code for that? Please help. 512-947-9932. Thanks!