Home >> Land Rover >> 2017 >> Discovery Sport SE >> Repair and Diagnosis >> Accessories & Equipment >> Infotainment >> Diagnostic Trouble Code Index DTC: Audio Head Unit (AHU) -- Discovery Sport/L550 >> Diagnostic Trouble Code Index DTC: Audio Head Unit (AHU) >> Description And Operation >> DTC B1D79-13: Microphone Input - Circuit open >> Possible Causes