When the washer drains, are both pumps used to facilitate the drainage or just the smaller drain pump by itself?

I'm having a non-draining issue but cant see to pinpoint the issue. The drain line goes to the disposal at the sink. the line looks clear and the disposal is clear. I removed the small drain pump and don't see any debris. and the flapper moves freely as it should. When I run the drain cycle, I can see and hear the smaller pump running but the water doesn't drain out. I was wondering if the larger pump also was supposed to run during drain cycle.

please help!