Bosch dishwasher won't drain. The pump works but it just swirls the water around in the sump.

I pulled the machine out and ran a snake through the entire drain hose and it seems clear. There is no air gap in the system.

There's no debris in the sump or around the impeller, and I didn't feel any foreign object by poking my finger into the drain outlet in the sump.

The dishwasher ejects no water even with the hose disconnected from the sink drain. Is there a relay used to open and close the dishwasher drain that could be stuck closed? Any other suggestions?