I am still involved in the process of moving from one house and city to another. Having received the most timely offer of a Quantum powerchair by a friend, I was able to leave the Permobil M300 at my old house for use there while I pack and the Quantum at my new house - thereby not having to move powerchairs from home to home as I work at each location. I save lots of room in the van in not having to move the chair each time; more room for packed items.
Over a year ago the Permobil's motors failed, one after the other - and one replacement motor also appeared to malfunction requiring its replacement.
More recently it was the power control unit (my term) which failed; the computer or controller board which distributes the power to the motors from the joystick commands.
My technician discovered that by unplugging the wiring harness' Molex connector to that motor and then reconnecting it - the system seemed to reset and become operational again.
This required someone to remove the rear plastic housing and unplugging/replugging the correct connector as described above.
This happened so often that I chose to leave the rear plastic housing off for ease of accessibility.