MDX V6-3.7L (2007)
Information Bus: Description and Operation
How the Circuit Works
The multiplex integrated control system sends digital signals between control units through shared wires to reduce the number of wires to make harnesses
lighter. A control unit converts input signals from switches and sensors to digital signals. The control unit sends the digital signals to the other control
units as serial data over dedicated communication lines. When the appropriate control unit receives the digital signal, it converts the signal back to an
operational command, such as operating a relay.
The multiplex integrated control system schematic shows power, grounds, and communication lines.
There are two different networks within the multiplex integrated control system. They are:
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Body Controller Area Network (B-CAN)
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Fast Controller Area Network (F-CAN)
The body controller area network (B-CAN) transmits information at 33.33 kbps, and the fast controller area network (F-CAN) transmits information at
500 kbps. Both networks share information between multiple electronic control units and work together to form the multiplex integrated control system.
The gauge control module translates information from B-CAN to F-CAN and from F-CAN to B-CAN to allow the networks to share information.
B-CAN Network
B-CAN information travels across the communication lines at a slower speed for convenience-related operations that do not require a high process speed.
The following control units and components operate on the B-CAN network:
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Gauge Control Module
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Combination Switch Control Unit
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Climate Control Unit
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Control Block in the under-hood fuse/relay box
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Multiplex Integrated Control Unit (MICU) (in the under-dash fuse/relay box and the rear fuse/relay box)
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Audio Unit
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Immobilizer-Keyless Control Unit
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HandsFreeLink Control Unit
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Driver's MPCS Unit
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Driver's Power Seat Control Unit
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AcuraLink Control Unit
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Power Tailgate Control Unit
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Gauges and Indicators
For safety reasons, the headlight and wiper/washer circuits of the B-CAN network have a backup circuit in the event of a network wire or control unit
failure that would affect system operation.
F-CAN Network
F-CAN information travels across the communication lines at a faster speed for "real time" functions such as fuel, emissions, and traction control data.
The following control units and components operate on the F-CAN network:
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Gauge Control Module
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PCM
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VSA Modulator-Control Unit
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Yaw Rate-Lateral Acceleration Sensor
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Steering Angle Sensor
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TPMS Control Unit
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SH-AWD Control Unit
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SRS Unit
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AcuraLink Control Unit
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Active Damper Control Unit
Since messages on the F-CAN network are typically of higher importance, a second wire monitors communication circuit integrity.
