Originally Posted by FastMover

The whole concept of "Neutral" in the Toyota technology requires a pretty large shift from conventional thinking. There never occurs a mechanical detatchment of the axle and power components in this system. To faithfully replicate a conventional transmission in "neutral" therefore requires some pretty smart decisions on the part of the ppowertrain computer. It has to: 1) supply no driving force to the axle, either positive or negative (sounds easy until you consider number 3 below); 2) protect MG1 from overspeed; 3) simulate a coasting condition if the vehicle is in motion from kenetic energy; and 4) respond correctly to braking inputs, either by the "normal" braking conbination, or by the friction brake alone.