Edgestar BIDW1802 Dishwasher - Started with E4 temp. error, now wash pump not running.

[bpoole23]

From the start, I was getting an E4 code after wash cycles. Dishes were still clean, and I could run the dishwasher for another cycle after I reset it. Eventually it just stopped cleaning dishes.

Ran factory diagnostics, I'll refer to the following as baseline condition... it fills with water fine, it heats the water but the temperature readings are incorrect, like 20-30*C below what I measure inside the dishwasher, it is completely silent when it is supposed to be running the wash pump, then the drain pumps works fine to drain the sump.

First I replace the thermistor, this didn't change any of the baseline behavior. Next I replaced the user interface board still no change in baseline conditions. Next I replaced the PCB, somehow still no change to baseline conditions.
At this point thought maybe the wash pump/motor had issues. Last night I removed the wash pump assembly and took it to a electrical motor repair shop. They tested it and said it works fine.

So at this point, the temperature reading is incorrect and the wash pump doesn't work at all.

What can I try next to avoid buying a new dishwasher?

1. Replace any additional parts?
2. Can I try to test the PCB with a multimeter to figure out what's malfunctioning?
3. ANYTHING else I can do? 

Service Manual: https://www.manualslib.com/manual/1533169/Edgestar-Bidw1802.html

Also, this dishwasher appears to be the same as the Frigidaire FFBD1831 if that helps in any way.

[bpoole23]

Revision... it gave me the E3 code, NOT E4. Also, after diagnostic mode finishes the screen displays "F2"

[bpoole23]

Can't figure out how to delete this post but...

Reinstalled the wash pump, hooked everything back up, and everything appears to be working fine now!