Siemens WFXD5201UC Front Load Washer won't complete cycle.

Shortly after the warranty expired, our Siemens WFXD5201UC Front Load Washer began to stop mid-cycle. At first it was "occationally", now it is "usually". But, it is still random, and happens at odd times in the cycle.
It most often stops with about 21-35 min remaining on the 59 min Regular cycle but will go as low as 1 min remaining. Occationally it will complete the cycle and beep but the clothes will still be soaking wet. The times I have caught it in the act, it is after the pump runs to drain the water, the drum doesn't turn to spin out the load. All the cycle indicator LEDs go off except the "Door Locked" indicator, no error codes show.
Even the "Rinse and Spin" cycle will hang up. I've tried the "Quick Wash" cycle and others with the same results. Tried other spin selections... no difference
My 1st thought was that there was some high speed spin contact for the motor that it wasn't recieving. I found the schematics and tore everything apart and nothing like that. The motor controller appears to be a VFD-like device that linked to the main controller with only a couple wires (some Comms protocall???). I would think if it was an issue with the main controller it would be more consistant?
Thanks