Faulty Ford DEF Heater
Some 2011-2014 Ford F-Super Duty vehicles equipped with a 6.7L diesel engine may exhibit an illuminated MIL and DTC P2043 (fault in the DEF reductant heater assembly).
Using a integrated diagnostic system (IDS) or equivalent, check for DTCs. If P2043 is present, replace the reductant heater assembly. The P/N for pick-up applications is BC3Z-5J225-L. The P/N for chassis cab is BC3Z-5J225-M.