Multiplex Communication
WARNING: This page is about a different car, the 2005 Honda Civic, 2004 Honda Civic, 2003 Honda Civic, and 2002 Honda Civic. However, it is still accessible from the selected car via links, so may be relevant.
To reduce the number of wire harnesses, digital signals are sent via shared multiplex communication lines rather than sending normal electrical signals through individual wires.
- The input signals from each switch are converted to digital signals at the central processing unit (CPU).
- The digital signals are sent from the transmitting unit to the receiving unit as serial signals.
- The transmitted signal is converted to a switch signal at the receiving unit, and it operates the related component or monitors a switch.
- There are exclusive communication lines between the ECM, the gauge assembly, keyless receiver unit, and the under-dash fuse/relay box.