How to Check the ANC/Active Sound Control System in this Check Mode

Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode. Make sure the audio system is turned off.
Push and hold the preset No. 1 and No. 6 buttons.
While holding the buttons, push the VOLUME/POWER knob to on.
Release the buttons, and the self-diagnosis begins.

Fig 1: Identifying Audio System Buttons (With Navigation And Without Navigation)
Courtesy of AMERICAN HONDA MOTOR CO., INC.
With the engine stopped, and while in DIAG mode, turn the ANC ON to OFF by pressing the No. 1 button. A low frequency hum (50 Hz) should sound for about a minute.
- If the hum does not sound, check for an open in the wire between the ANC/active sound control unit and the audio unit.
- If the hum sounds for a second, check for an open in the wire between ANC/active sound control unit and the microphone.
  NOTE: The ANC/active sound control system is cancelled when any door is opened.