When run in diagnostic or regular cycle, the circulation pump only runs every so often. I can hear the relays clicking, but the pump doesn't always run.

I have put 110v directly to the pump motor and it runs fine.

The control board was quite dirty when I pulled it out - cockroach poop and carcasses. Cleaned it up and put it back in.

Diagnostic mode came back with error 6-4 which is a water level issue. I re-leveled the dishwasher and that error doesn't come up anymore. No errors after a diagnostic run at the moment.

So is this a bad pump (how?) or a bad control board, or something else? Thanks.