Kenmore F20 Error Code

Hi,

I have a Kenmore Elite HE3T that is throwing a F02 error code. I have read many of the posts about the code. I have cleaned out the trap, small amount of debris. Tried again and still got the F02. I removed the drain pump and I was checking the drain hoses and noticed something about the black hose coming from the bottom of the tub to the drain pump. It feels like there is some type of plastic ball in that hose connects to the tub. Is that suppose to be there? I wanted to make sure before I try to remove it.

Thanks,
Gary