After searching as you suggested the tales of doom & gloom regarding the "Flashing light" are numerous. I haven't had this issue (3 years of ownership) until now. For the record, I installed two pre catalitic HO2 sensors today. The neg battery connection was removed prior to doing work and was disconnected for 2/3 hrs. This cleared all computer memory-codes including Keep Alive Memory. Either the clearing of the ODBII caused this to occur (start up diognostic?, Glitch?) or the problem has existed since I purchased the truck. I soppose it is possible (upon reboot) the OBD found the error. It's also possible this happened to the previous owner and I was not aware of it (since the flashing stops the first time vehicle is turned off). If the problem was pre existing over the 3 years I've owned the truck shoulden't the tranny have died! The trans shifts normally and overall trans performance has not changed in the time I've owned the vehicle. I hesitste to grant the Ford service dept. access to my wallet unless it is absolutely necessary! Raoul, let me know what you think. All comments are welcome so lets hear it!