More data. I have had my 03 EB since June, and early adopter. When I had a few hundred miles on it, my "check advance trac" came on. I happened to be (really) right in front of a Ford dealership and it was about 8am, so I just pulled in an got an line. A service manager chatted with me, and then with some other employees, and came back and said that the truck was so new that they were not sure they would know how to service this. But, he suggested I might want to cycle the ignition and see if the warning cleared. It did. Then I drove around his lot for a while, and it did not come back, so I left. Now, I have 12,000 miles on the truck and have never seen this happen again. I have been assuming that my Advance Trac is, therefore, working.