Multiplex Control Unit Input Test

Before performing the multiplex control unit input test, do the multiplex troubleshooting (Mode 1 and Mode 2).

Passenger's Unit 

1. Remove the passenger's multiplex control unit from the passenger's under-dash fuse/relay box.
2. 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 3.
   Fig 1: Inspecting Connector & Socket Terminals (Passenger's Unit)

   Courtesy of AMERICAN HONDA MOTOR CO., INC.
3. Make the following input tests at the 22P connector B and the passenger's under-dash fuse/relay box socket connector A.

   Be careful not to spread the fuse box connectors.

   • 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 4.
   Fig 2: Passenger's Unit Input Test Table

   Courtesy of AMERICAN HONDA MOTOR CO., INC.

   Door Unit 

4. Carefully pry off the driver's door switch trim (see FRONT DOOR PANEL REMOVAL/INSTALLATION ).
5. Disconnect the connectors (A).
6. 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 7.
     Fig 3: Inspecting Connector & Socket Terminals (Door Unit)

     Courtesy of AMERICAN HONDA MOTOR CO., INC.
7. Make the following input tests at connector A (20P).
   • 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 8.
   Fig 4: Door Unit Input Test Table

   Courtesy of AMERICAN HONDA MOTOR CO., INC.

   Driver's Unit 

8. Remove the driver's multiplex control unit from the driver's under-dash fuse/relay box.
9. 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 10.
     Fig 5: Inspecting Connector & Socket Terminals (Driver's Unit)

     Courtesy of AMERICAN HONDA MOTOR CO., INC.
10. Make the following input tests at 22P connector B and the driver's under-dash fuse/relay box socket connector A.

    Be careful not to spread the fuse box connectors.

    • If any test indicates a problem, find and correct the cause, then recheck the system.
    • If all the input tests prove OK, one of the multiplex control units (door, driver's or passenger's) must be faulty.

      Substitute a known-good control unit for the one that's is most closely related to the failure, then recheck. If the symptom continues, replace the next most likely control unit until the symptom goes away.

      Fig 6: Driver's Unit Input Test Table

      Courtesy of AMERICAN HONDA MOTOR CO., INC.