Check Microphone With Line Diag Mode

WARNING: This page is about a different car, the 2021 Subaru Ascent. However, it is still accessible from the selected car via links, so may be relevant.

Turn the ignition switch to ACC.
Press the button (b) twice with the button (a) pressed.

Courtesy of SUBARU OF AMERICA, INC.

NOTE: Pressing the button (a) for 3 seconds or more, or turning the ignition switch from the OFF to ACC position can exit the diagnostic mode.
{Line Diag} screen is displayed.
Check the microphone level with the {Microphone} in the {Line Diag} screen.

Courtesy of SUBARU OF AMERICA, INC.

Check that the microphone input level varies depending on the sound and voice.