Just to note that PADM uses the magnetorheological fluid approach rather than the electronically activated valving used in PASM:
Porsche Active Drivetrain Mounts are filled with magnetorheological fluid containing microscopic iron particles. Each mount contains two chambers, with a circular slot that allows the fluid to pass between the top and bottom chambers. At the centre is a doughnut-shaped electromagnet, which is used to control the fluid’s viscosity.
At low engine speeds, the fluid flows freely to provide a more comfortable driving experience. However, the voltage that reaches the electromagnetic is controlled by the ECU, with the map based predominantly on engine speed.
As the engine rpm increases, so does the electromagnet’s voltage, creating a stronger magnetic field. This increases the chains of aligned iron particles, decreasing the fluid’s viscosity. Eventually, these chains render the mount solid.
This technology has been used for many years in suspension dampers which you’d have thought experience a much more punishing environment than engine mounts, although the latter probably will be subjected to a wider frequency range of inputs. If the electronics are external to the mounts (via the ECU and a PADM electronic module) there’s not much to go wrong within the mount other than a coil or associated wiring failure … but maybe I’m missing something?
Jeff
