See also:

SCAN (only when connecting USB storage device)
Scan is operated in the same way a CD is played. For details, refer to “Scan (type A, B and C audio)”. NOTE When an iPod® is connected, you cannot select the SCAN mode. ...

Electrical system
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How to insert a CD (type A)
While the ignition switch is in the “Acc” or “ON” position, hold a disc with a finger in the center hole while gripping the edge of the disc, then insert it in to the slot (with the label side up) ...