The other day, my old Whirlpool Duet washer stalled near the end of a drain cycle. I couldn't get the door to unlock, couldn't get it to reset, etc. So I removed the access panel, manually opened the door, took out the clothes, vacuumed out the excess water and the drain hose, checked the water pump (the motor housing was filled with nasty, stinky black water), bought a new water pump, and replaced it. But that didn't fix the problem.

If I leave the machine unplugged for awhile, then plug it in and try to start any cycle, the door locks, and nothing else happens. However, if I unplug the machine and then plug it back in quickly, it seems like that forces it to go to the next step in the cycle. For instance, the basket will fill with water, but then it stops and won't advance to the next cycle. If I unplug/plug again, the machine lets out a click and does nothing. If I do it again a couple more times, the machine drains but then stalls out again.

So in short: the door locks, the basket will fill and drain if I plug/unplug repeatedly, but the basket won't spin, the cycles won't advance on their own, and the door won't unlock.

When I check the diagnostic codes, I get several in this order: F9E2 (Pump Drive System Error); F9E1 (Drain Longer Than 8 Minutes); F8E1 (No Water Detected Entering Washer or Pressure Switch Trip Not Detected); and F3E2 (Water Temperature Sensor Error).

Do you have any idea what is going on? Perhaps the drive motor has gone bad? Maybe the CCU?

I would appreciate any guidance.

It drains quickly.
The unit does not spin.
It fills to the proper level every time I've tested it lately except once when it wouldn't stop filling until I pulled the plug. Then it drained quickly when I plugged it back in.
I've tried to run a diagnostic cycle, but the washer only locks the door and then won't respond to key presses. At that point, I can only get things going by unplugging and plugging back in repeatedly. However, the door never unlocks unless I manually open it.