Horn (High)/Security Horn

Remove the front bumper center upper beam (see FRONT BUMPER CENTER UPPER BEAM REPLACEMENT ).
Remove the front bumper (see FRONT BUMPER REMOVAL/INSTALLATION ).
Disconnect the 1P connector (A) from the horn (B).

Fig 1: Identifying 1P Connector, Bolt And Horn
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Remove the bolt(C).
Test the horn by connecting battery power to the terminal (A) and body ground to the bracket (B). The horn should sound.

Fig 2: Identifying Horn Terminal And Bracket
Courtesy of AMERICAN HONDA MOTOR CO., INC.
If the horn fails to sound, replace it.