•  The audio system has an on-board diagnostic function and diagnostic assist function to facilitate audio system diagnosis.

•  The on-board diagnostic function consists of the following functions: A malfunction detection function, which detects overall malfunctions in the audio system-related parts; a memory function, which stores detected DTCs; and a display function, which indicates system malfunctions via a DTC display.

•  There are two methods for reading and clearing DTCs. They include activation of the on-board diagnostic test mode of the on-board diagnostic function, which is operated using the audio unit, and the Mazda modular diagnostic system (M-MDS). The displayed DTCs differ depending on whether the on-board diagnostic test mode or the Mazda modular diagnostic system (M-MDS) method is used. Additionally, because some DTCs are not displayed in the on-board diagnostic test mode, use the Mazda modular diagnostic system (M-MDS) before performing the procedure.

•  The diagnostic assist function is a function for forcibly operating audio system related parts to verify their connection condition and operation status. In addition, the specifications for the audio system related parts are displayed in the information display to enable their verification.