Welcome.

I'd first check to see what codes it is giving you. That OD light has a meaning -- it's got a code(s) stored.

Also, how is the fluid? Is it at the correct levels? Is it burnt smelling or brown looking?

 

 

Yup, it always happens at the worst time.

The transmission will not illuminate a check engine light because it's got nothing to do with the engine. The OD light is like the transmission's check engine light.

 

 

It sounds like it may be in limp mode if it won't go past 2nd gear and 40mph. I haven't had that experience with my truck but I have with my 05 Dodge Magnum RT. Shutting the engine off and putting it in park would get it working correctly again temporarily.

 

The simplest solution is if the 2-3 accumulator piston failed. If it were me, and I could, I would drop the pan and the valve body to see what I could find.

D

 

Try taking the negative cable off the battery and be sure to isolate it by wrapping a shop towel or something around it so it cannot hit or touch the neg post then take a jumper wire with alligator clips from the pos post to the engine block that will drain out lots of things but when you reconnect everything after a half hour it will learn a shift pattern again. Worth a try and it worked for me.