Frigidaire dishwasher not pumping water

I started having a problem with my Frigidaire dishwasher not getting anything clean. I searched through numerous forums and checked out all of the most common remedies. Here’s what I have now. I removed the dishwasher lower spray arm, filter, soil director, and volute cover to expose the pump/impeller. There was nothing blocking the impeller and it spins freely by hand. When I put the dishwasher into a wash cycle, it fills the basin with water. Then the motor starts and it circulates the water for about 10 seconds before the flow stops completely. The motor keeps running and there is no audible change in the sound of it. I can see the impeller through the water and it is not spinning. How is the impeller attached to the motor? Is it keyed? I have been reading that it may be pressed on to the motor shaft. Is my solution to replace the impeller? I am assuming the motor can only be taken out from underneath the unit. (This presents a problem for me since our home’s previous owners added a tile floor and now I do not have enough space to slide the unit out from under the countertop, even after adjusting the legs down) If I cancel the wash cycle, all of the water drains from the unit just fine. Any help would be appreciated.