Multiplex Control Unit Input Test

Remove the driver's dashboard lower cover (see DRIVER'S DASHBOARD LOWER COVER REMOVAL/INSTALLATION ).
Disconnect the under-dash fuse/relay box connectors C, E, F, J, K, O, P, Q, X and Y.
NOTE: All connectors are wire side of female terminals.

Fig 1: Identifying Multiplex Control Unit Connector Terminals
Courtesy of AMERICAN HONDA MOTOR CO., INC.
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.
Fig 2: Multiplex Control Unit Input Test (Connectors Disconnected)
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Reconnect the connectors to the under-dash fuse/relay box, turn the ignition switch ON (II) to keep the system awake 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 (Connectors Connected - 1 Of 2)
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Fig 4: Multiplex Control Unit Input Test (Connectors Connected - 2 Of 2)

Courtesy of AMERICAN HONDA MOTOR CO., INC.