Some 2011 Mercury Milan and Mariner and 2011-12 Ford Fusion, Escape and Lincoln MKZ hybrid vehicles may turn on the Check Engine light and store trouble code P0016 (crank/cam position correlation) in the PCM.
Ford says if there are no driveability symptoms associated with the code it's most likely bogus and caused by software anomalies in the PCM. Reprogramming the module with updated calibration files is the only surefire fix.
Check with a dealer for the application specifics of the flash.