Some 2021-2022 F-150 vehicles equipped with the branded B and O audio the rear speaker audio may appear to have reduced sound. Fading audio volume to the rear speakers/reduced audio volume from rear speakers is an operating characteristic of the B and O audio system. If the audio control module (ACM) and digital signal processing (DSP) module passes the Self-Test and Network Test without any diagnostic trouble codes (DTCs) setting as hard faults, no further diagnostics is recommended.
