Some 2021 F-150 vehicles built on or before 01-Feb-2021, 2017-2020 F-150 vehicles equipped with a 3.5L EcoBoost engine, 2018-2020 F-150 vehicles equipped with a 2.7L EcoBoost or 5.0L engine, 2019-2020 F-150 vehicles equipped with a 3.0L diesel engine may exhibit a high pitched squeal or whistle type noise from the engine compartment after the engine is shut off. This condition may be due to the air conditioning (A/C) low side system pressure exceeding the high side pressure resulting in equalization of A/C system pressures through the A/C compressor. An updated A/C compressor has been released to resolve this concern. For claiming, use causal part 19703 and applicable labor operations in Section 11 of the Service Labor Time Standards (SLTS) Manual.