I have a 96 Mercury Sable with a flashing o/d light. I have read about how this can be an indicator that there are tranny codes.

I have an OBD II code reader and it has worked pretty slick in the past, but it doesn't pick anything up with this problem.

When looking at the tranny fluid it has a nice red color but is bubbly. The fluid level is fine. The car shifts good and I have not noticed any problems while driving.

Just looking for some ideas on why I'm getting a flashing o/d light.

 

you are right about the flashing meaning you have transaxle codes. I am not sure your scan tool is trans capable though. bubbling or aerated fluid usually means there is too much fluid in the transaxle. if you really want to pull the codes then maybe an autozone trip is in your future cause I think they will do it free. or if you are worried then you can always go to a profesional and see what is up. did you add fluid lately? maybe it's overfull which triggered the light.