Key-In Reminder System
WARNING: This page is about a different car, the 1996 Honda Accord. However, it is still accessible from the selected car via links, so may be relevant.
When the ignition key is not removed, the key-in beeper in the integrated control unit senses ground through the closed ignition key switch. When you open the drivers door, the beeper circuit senses ground through the closed door switch. With ground at the "BLU/WHT" and "A1" terminals, the beeper sounds. See WIRING DIAGRAMS .