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SSM 49050 - 2018-2020 F-150 - 5.0L Flex Fuel - Illuminated MIL With DTCs P0171/P0172/P0174/P0175
Some 2018-2020 F-150 vehicles equipped with a 5.0L engine may exhibit an illuminated malfunction indicator lamp (MIL) with diagnostic trouble codes (DTCs) P0171, P0172, P0174 and/or P0175. This may be due to incorrect flex-fuel learning, which is often caused by customer refueling habits when adding only small amounts of fuel, the vehicle mislearning of inferred ethanol fuel mixture (FF_INF value) or a component concern. Refer to pinpoint test H in the Powertrain Control/Emissions Diagnosis (PC/ED) Manual for diagnostics and Flex Fuel GSB for additional flex fuel system information and diagnostic tips.