Home › Jaguar › 2012 › XK 2D Convertible › Repair and Diagnosis › General Information › DTC Index › Diagnostic Trouble Code Index DTC: Audio Control Module (ACM) -- XK/X150 › Diagnostic Trouble Code Index DTC: Audio Control Module (ACM) › Description And Operation › Audio Control Module [ACM] › DTC B1D78-13: Auxiliary input - Circuit open › Possible Causes