What were you doing when the car went it to limp mode? Which is 2nd gear in our cars, however the thing that is standing out to me is you say your speedo doesnt work in limp mode. That doesnt seem right, it should work fine in limp mode, at least mine always has. The Cel for a trans code never comes on in my car either, But if its in limp mode it will have a code stored in the tcm. You can try doing the key dance but I seriously doubt it will show any tcm code either. A shop should scan it for you for free anyways. Dont believe them if you think there to quick to judge or tell you right away you need a rebuild. Write the codes down and bring them to us. Descriptions help too.