No Power Transmission

Because there is no central clutch between the combustion engine and active gearbox, the active gearbox must offer a state in which there is no power transmission between the transmission input shaft and transmission output shaft. This makes it possible, for example, for the combustion engine to rotate freely without moving the vehicle. Conversely, the vehicle can roll freely without torque being output or absorbed by the combustion engine.

The "no power transmission" state is attained by opening all four multidisc clutches. When the combustion engine is running the electric machines also rotate at the same time, in this case without load, thus operating as neither a generator nor as a motor. At a combustion engine speed of 4000 RPM or higher, the electric machines would reach speeds higher than those for which they are designed. Therefore, in this transmission state, the speed of the combustion engine is regulated electronically to a value below 4000 RPM.