WARNING: This page is about a different car, the 1994 Acura NSX and 1993 Acura NSX. However, it is still accessible from the selected car via links, so may be relevant.
This signals the ECM when the clutch is engaged. See Fig 1
and Fig 2
.
Fig 1: Clutch Switch Signal (M/T) Diagnostic Flowchart (1 Of 2)
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Fig 2: Clutch Switch Signal (M/T) Diagnostic Flowchart (2 Of 2)