Civic EX Sedan L4-1668cc 1.7L SOHC (VTEC) MFI (2001)
Information Bus: Description and Operation
Circuit Description
How the Circuit Works
The conventional portion of the electrical system carries DC (or A/C) power through separate wires to each component. The multiplex portion of the
system, however, sends digital signals between control units through shared wires to reduce the number and weight of wire harnesses. The signals from
each switch are converted to digital signals within the receiving multiplex control unit. The digital signals are sent from one multiplex control unit to
another as serial data over dedicated communication lines. When the appropriate control unit receives the digital signal, it converts it back to a switch
signal and operates the related components.
The multiplex control system schematic shows its power, grounds, and communication lines. The ignition key light is also shown because it is used to
blink DTCs in the system's self-diagnosis function. The rest of the multiplex control system wiring is shown in the following circuit schematics:
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Charging System
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Horns
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HVAC
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Fans
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Low Oil Pressure Indicator
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Seat Belt Reminder
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Lights-on Reminder
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Key-in Reminder
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Key Light Timer
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Gauges and Indicators
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A/T Gear Position Indicator
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Wiper/Washers
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Headlights
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Trunk Light, Ceiling Light and Spotlights
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Entry Light Control System
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Power Door Locks
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Keyless Security Alarm System
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Interlock System