I have a Bosch SH43R dishwasher. It has started not always filling enough on a cycle, leading to poor wash performance (often it can't even get the soap out of the dispenser).
Frustratingly, it's not every cycle. Awkwardly, adding 2-3 cups of water sets things right (the water level then comes up a few cm above the drain mesh). So I've been running it each night by listening for a lack of enough sloshing, then adding water by hand. Ugh.
I've removed the integral filter and fill solenoid (Bosch part #00622058). The filter was a little dirty, but not bad. I measured 4.1 gallons per minute out of the inlet hose: seems like plenty. But the problem persists.
I know this model is a "timed fill" meaning the dishwasher computer has no idea how full the tub is.
How can I run a diagnostic cycle, as this particular model has no display (other than a useless red LED that shines on the floor)?
What could be the low fill cause? Can a weak solenoid do this?