I noticed something interesting yesterday.... Useless but interesting. Coolant Temp above 157F, "READY" and at a complete stop. In Neutral: - No matter how much throttle input you give the car, nothing happens at all. In Park: - If you give the car any throttle input at all, the ICE starts. But it stops as soon as you let go of the throttle. - The RPM does not vary with amount of throttle input. The engine (if I recall) was at around 1000rpm. - While ICE is running, the MFD does not indicate any charging is happening, so it seems like the engine is just is idling the the MG1/MG2 is free wheeling. I wonder why Toyota did this? Perhaps it's to help diagnostics in the future -- a way to get the ICE to run during testing?
The most probable and simple answer is to allow mechanics to make the engine run on demand during/after their work on the ICE.
Can't tell you why TMC did that, but it's not how techs set the engine to run constantly. Have a look here for the actual procedure.
