E20 is a motor resistance error. This was my first ever dishwasher repair. I went pretty slowly. Assuming the problem was motor failure, I bought a motor and accessories. While taking apart the machine and removing the current motor, I flushed all the residual water from the motor and shook it quite a bit. While I never saw any particular “thing” that may have been jamming the impeller, I temporarily reconnected the power to the unit and start a rinse cycle. To my surprise, the motor started right up and no E20. I opted not to even install the new motor. Note, reinstalling the motor was easy, but the original hose clamp was very cheap and was virtually impossible to reuse. So I opted to use the $14 replacement hose clamp that was very high quality. We have now run 5-6 loads and no issues whatsoever.