WARNING: This page is about a different car, the 2011 Honda Insight and 2010 Honda Insight. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Audio System Diagram - Without Navigation (Except DX Model) (1 Of 2)
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Fig 2: Audio System Diagram - Without Navigation (Except DX Model) (2 Of 2)