95 4.3W 4L60E Trans was rebuilt with all new inc Converter about 5 years ago and has about 75k on it now. There are no codes either.

Here is what happened today on the Highway. Everything was going along fine as always cruzing at 70, than all of a sudden the trans dropped out of overdrive into 3rd,ok I thought,what's up with that?t So I thought I'll check it out when I get to work. Soon after, it was like someone threw it into neutral, at that point I coasted to the side of the highway. No forward or reverse at all!! Called a Tow to my house,once truck was dropped of I thought what the Hell,I'll give it a try. Trans works perfect again,fluid is pink not burnt. If anything broke or was bad this could not happen. Now, I am thinking this must have something to do with a sensor or something electrical. Because broke Transmissions do not just fix themselves!! I also must add that the drop out of OD happened to my son about 5k ago but it never repeated it until now wit the added loss of everything else.
Thanks in advance, Hope we have some sharp Tranny guys on here. HELP!!

 

Hmmm, No one knows anything here??

 

Nice 'bump'...

Sounds like an electrical problem.