I had the same problem, went to go for a ride on Meteor and found Engine MIL light continually on after start up, light stayed on during ride but bike was going fine. Trip to R/E dealer the following day, put it on tester showed the fault as Undefined, they switched off light and so far all ok. Said if it happens again to bring it back for further investigations. I didn't know about the Engine Temp Sensor issue. Happened at 550 miles.