Auto-off Headlight Control Unit Input Test

WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2004 Honda Odyssey, 2003 Honda Odyssey, 2002 Honda Odyssey, 2001 Honda Odyssey, and 2000 Honda Odyssey. However, it is still accessible from the selected car via links, so may be relevant.

Before testing the exterior lights control functions, troubleshoot the multiplex control system (see TROUBLESHOOTING ).
1. Driver's Multiplex Control Unit
Remove the driver's multiplex control unit from the driver's under-dash fuse/relay box.
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 1: Identifying Driver's Under-Dash Fuse/Relay Box Socket Terminals
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Fig 2: Identifying Driver's Multiplex Control Unit Connector B Terminals
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Fig 3: Identifying Driver's Under-Dash Fuse/Relay Box Connector A Terminals
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Fig 4: Identifying Driver's Under-Dash Fuse/Relay Box Connector O Terminals
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Fig 5: Identifying Driver's Under-Dash Fuse/Relay Box Connector Q Terminals
Courtesy of AMERICAN HONDA MOTOR CO., INC.
With the driver's multiplex control unit still disconnected, make these input tests at the fuse/relay box socket.
- 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 6: Fuse/Relay Box Socket Input Tests (Driver's Multiplex Control Unit Disconnected)
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Reconnect the driver's multiplex control unit to the fuse/relay box, and perform the following input tests at the appropriate connectors on the back of the fuse/relay box (see DRIVER'S 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, go to step 6.
Fig 7: Fuse/Relay Box Socket Input Tests (Driver's Multiplex Control Unit Connected)
Courtesy of AMERICAN HONDA MOTOR CO., INC.
1. Door Multiplex Control Unit
Remove the driver's door panel, and disconnect the 20P connector A from the door multiplex control unit.
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 8.
Fig 8: Identifying Door Multiplex Control Unit Connector A Terminals
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Reconnect the connector to the unit, and make these input tests.
- If a test indicates a problem, find and correct the cause, then recheck the system.
- If all the input tests prove OK, go to step 9.
Fig 9: Door Multiplex Control Unit Input Tests
Courtesy of AMERICAN HONDA MOTOR CO., INC.
If all the input tests prove OK, one of the control units must be faulty. Substitute a known-good control unit for the one that is most likely at fault, then recheck the system. If the system works properly, the original control unit is faulty; replace it. If there is still a malfunction, substitute a known-good control unit for the next most likely unit to be at fault, and recheck. If the system works properly, the original unit is faulty; replace it.