My F I light came on under speed, and stayed on yesterday on way to see son on I-40. Pulled in to get gas, then it was gone. Got back up to about 80 mph and it came back on. Stopped at sons, now it is off. It is not blinking any codes using the process as described by Jeff B. above. I am guessing a plugged hose, vacuum leak, or a bad fuel tank filled gasket? My 2003 ST 1300A with 102k miles on it runs great.