There are solenoids yes, but these change gear ration for MG2 to output.

Motors do the torque paths. So varying motor speeds and directions change the torque contributions of each. There is no way to fully decouple the engine.

In the conversion to use both E motors the engine input shaft is ...

...

This is an autobox. Also a series hybrid so it will never be able to run in "just ICE" mode. It requires the Emotors to move torque through the gearbox.

https://openinverter.org/wiki/Lexus_GS450h_Drivetrain


Thank You for link, the question was more in line if the gearbox has some sort of ...

Yes this is possible.


Thanks Tom for the anwser. Are there any specifics required from the engine? Obviously the simplest route would be to use the 2GR it came in from the factory what about a different engine, I pressume it doesnt care beyond the point it gets some torque on the input shaft ...

Hello,

Im currently thinking if it would be possible to use the gs450h gearbox still with an ICE (engine) attached to it to use the hybrid powertrain?

What im trying to achieve?
Bundle the GS450h hybrid powertrain to an ICE engine to use the benefits of the electric motors for low end torque.