I looked it up in the manual, and this code said something about the motor, and the solution was to turn off the water and unplug the machine - and call customer service. Yup, I'm thinking something is really really wrong with my washing machine. So I told Jeffrey I needed him to look at it - and he did and called customer service - and couldn't get it working. At which point they told him to leave it unplugged for half an hour and then plug it in and try again.
So he did. And when he plugged it back in, it worked!
I threw a couple towels in with the rug after that so the load was more balanced, and it worked fine. Then today I washed towels. I was going to blame Beth for moving in and bringing tons of laundry, but apparently the motor just overheated and needed to rest. I don't know why it didn't stop like normal when there's an unbalanced load, but it just tried too hard - and I wasn't home to notice.
Scary for a little bit, though. I kept thinking, "What am I going to do without my washing machine?" Thankfully I had my wonderful husband to get it going again.