There is a diagnostic procedure in the factory service repair manual for engine light lit ,no codes . Did you take it to ford dealer ? MIL - is referring to check engine , service engine soon etc...
- MIL always on when engine is running (no DTCs):
- MIL circuits
- For Focus, Mustang, Town Car, Continental, LS6/LS8, Escape, Windstar, F-150, Expedition and Navigator/Blackwood:
- Instrument Cluster, Section 413-01 of the Workshop Manual.
- All Others:
- GO to NB1
SERVICE ENGINE SOON indicator
After the engine is started, the SERVICE ENGINE SOON indicator will prove out for a duration of three seconds. If the instrument cluster does not receive a message from the PCM within five seconds, the instrument cluster will illuminate the SERVICE ENGINE SOON indicator and log a diagnostic trouble code (DTC).
- An indicator is inoperative/always on - SERVICE ENGINE SOON
- Instrument cluster.
PINPOINT TEST P: AN INDICATOR IS INOPERATIVE/ALWAYS ON - SERVICE ENGINE SOON
CARRY OUT THE INSTRUMENT CLUSTER SERVICE ENGINE SOON INDICATOR ACTIVE COMMAND
Trigger the HEC active command MIL.
- Did the SERVICE ENGINE SOON indicator illuminate?
REFER to Powertrain Control/Emissions Diagnosis (PC/ED) manual.
INSTALL a new instrument cluster; REFER to Instrument Cluster . CLEAR the DTCs. REPEAT the self-test.