Hi Rogerreno, Please take what I say with a pinch of salt as I am NO expert.
I have recently had a similar fault in my Omega 3ltr Elite. As I would accelerate the car would stuter and go into limp home mode i,e it would stay in third with no power at all. If I stopped turned of and restarted the engine the auto gearbox warning would reset until I pulled of again.
The error code was the same as yours & pointed to the solonoid, However this was changed & the problem stayed. eventually it was traced to a pump! Unfortunatly I don't remember the name exactly but if you face the engine it is on the right hand side, low done on the front of the engine with a belt going around it.
Again I'm sorry if thats a little vague but as I said I am no expert but it may ring some bells with your garage/mechanic.
Good luck, Darren