I started getting this error code a couple of weeks ago. First it would appear during the spin cycle. Then it became more frequent and occurred intermittently at various times. I read all the forums but nothing seemed to fit. I found the service manual and ran the diagnostic tests. It passed them all. Then I found the problem. One of the wires in the motor harness (the short harness from the motor and position sensor to the set of connectors in the lower back of the machine) was broken. Because it is tightly wrapped in the harness it would show continuity until it started shaking as the drum turned. There was no outward sign of the problem. The clue was the intermittent nature of the problem. So if you have a similar problem test this cable while moving it around.
