See also:

Lubrication oil circulation in the refrigerant circuit
Operate the air conditioner compressor at a low engine speed (at idle or low driving speeds) a few minutes each month during the off-season to circulate its oil. ...

When the following messages are displayed
If one of the following messages is displayed while operating the CD player, determine the cause based on the following information. If you cannot clear those messages, please contact your SUBARU ...

MUTE button (if equipped)
Press this button if you wish to immediately cut the volume to zero. The audio display will show “MUTE”. If you press the button again, the original sound volume will return and “MUTE” turns off. ...