Well, I changed the sensor and it is fixed.
However, maybe one of you Chrysler technicians can clear something up for me. When I got the replacement sensor it came with an instruction paper. A note on the paper said "This service it will not repair REAR WHEEL SPEED sensor failures. Yet the kit has a replacement sensor. I called the chrysler parts department and they couldn't tell me anything definitive although one of the techs said that it depends on the code but said if the lights are on it would probably fix it. so I went ahead and did it anyway.
Kind of confusing direction. What does that mean?