Power Mirror Switch Test/ Replacement

Carefully pry the switch panel out from the dashboard.
Disconnect the 10P connector (A) from the power mirror switch (B).

Fig 1: Identifying 10P Connector And Power Mirror Switch
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Check for continuity between the terminals in each switch position according to the table.
Mirror Switch:

Fig 2: Mirror Switch Terminals Continuity Reference Chart
Courtesy of AMERICAN HONDA MOTOR CO., INC.
If the continuity is not as specified, replace the power mirror switch.