Trying to determine the next "phase" in the trouble shooting process...

So Far...
The DW starts just fine. Water enters and then the cycle begins. At various times for various setttings there is an electrical fault and the ominous **PF** flashes shutting the operation down.

What I know...
Water is entering and being circulated. It also drains properly when a cycle is cancelled.

The heating element was inspected and tested for continuity. It checked good, and when I run the cycle the water is hot to the point that if I open the unit it fogs my glasses...

The Hi-Temp sensor was also removed, inspected and checked for continuity. No problems there either.

There are no leaks and there is no outward indication that any of the wiring is bad.

The circulation pump and surrounding area is clean/clear of any obstructions and since it appears both bottom and upper spray arms are functioning I hesitate to suggest there is a problem there.

The unit was repaired under warranty when it was new...they replaced the control unit and touch panel. I didn't own the residence, and by default the DW, when the warranty repairs were performed so I can't say what caused the problem and the indications...

Is there an electrical or default test? How would I check the control panel and touch pad to determine if they are the problem?

THANKS in advance for any advice
A