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Multiplex Control Unit Input Test

  1. Remove the driver's dashboard lower cover (see DRIVER'S DASHBOARD LOWER COVER REMOVAL/INSTALLATION ).
  2. Unbolt the under-dash fuse/relay box and pull it down.
    NOTE: All connectors are wire side of female terminals.
    Fig 1: Disconnecting Under-Dash Fuse/Relay Box
    G01415630Courtesy of AMERICAN HONDA MOTOR CO., INC.
  3. Inspect the connector and socket terminals to be sure they are all making good contact.
    • If the terminals are bent, loose or corroded, repair them as necessary, and recheck the system.
    • If the terminals look OK, go to step 4.
  4. With the connectors still disconnected, make these input tests at the connector.
    • If any test indicates a problem, find and correct the cause, then recheck the system.
    • If all the input tests prove OK, go to step 5.
    Fig 2: Control Unit Input Test Chart
    G01415632Courtesy of AMERICAN HONDA MOTOR CO., INC.
  5. Reconnect the connectors to the under-dash fuse/relay box, turn the ignition switch ON (II) to wake-up the system, and make sure these input tests at the appropriate connectors on the under-dash fuse/relay box.
    • If any test indicates a problem, find and correct the cause, then recheck the system.
    • If all the input tests prove OK, the multiplex control unit must be faulty, replace the under-dash fuse/relay box assembly.
    Fig 3: Multiplex Control Unit Input Test (1 Of 2)
    G01415633Courtesy of AMERICAN HONDA MOTOR CO., INC.
    Fig 4: Multiplex Control Unit Input Test (2 Of 2)
    G01415634Courtesy of AMERICAN HONDA MOTOR CO., INC.
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