In my case, the problem was due to two red wires becoming detached from a sensor located on one of the larger hose/ducts upper left corner looking in through the rear access panel.
The crimp connector had fallen apart and the two wires were lying on the bottom of the chassis. I re-crimped the connector, plugged if back in and off it went.
I suspect the cause was excessive vibration due to moving the machine to a new house, and not quite getting the levelling correct.
ItsThatIdiotAgain, November 2017