On my washer, the fabric softener would not drain. I removed the top cover (3 screws in back) and found that there is a motor with a plastic cam and arm that re-directs the incoming water in one of 3 ways: To the detergent, to the fabric softener and none of the above.
The plastic arm popped off the motor shaft, probably due to vibration leaving the redirector aimed at the detergent and never the fabric softener. With a minutes careful work I was able to push the plastic piece back onto the shaft. It works fine now.
The redirector could have been left in the fabric softener position which would have starved the washer for detergent.