Originally Posted by upallnight

Instead of changing the whole mechatronic unit, I would send it to Gary to have him rebuild the one you have now. He will send the solenoid out for testing and if they are bad he will have them replaced.

Here's a video of him overhauling a ZH6hp26 valve body.

https://www.youtube.com/watch?v=MlDVqH9VEgQ

Dealers in his area send their cars to him to overhaul the trans.