Control Unit Input Test

Before testing the keyless entry/security control functions, troubleshoot the multiplex control system with mode 1 and mode 2 tests (see TROUBLESHOOTING ).
Multiplex Control Unit, Driver's:
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 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.
With the driver's multiplex control unit still disconnected, make these input tests at the connector and driver's under-dash fuse/relay box sockets.
- 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 5: Driver's Multiplex Control Unit Input Test Table (1 Of 2)
  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.
- 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 6: Driver's Multiplex Control Unit Input Test Table (2 Of 2)
  Courtesy of AMERICAN HONDA MOTOR CO., INC.
Multiplex Control Unit, Passenger's:
Remove the passenger's multiplex control unit from the passenger's under-dash fuse/relay box, and disconnect its connector.
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 7: Identifying Passenger's Fuse/Relay Box Socket Terminals
  Courtesy of AMERICAN HONDA MOTOR CO., INC.
  
  Fig 8: Identifying Passenger's Multiplex Control Unit Connector B Terminals
  Courtesy of AMERICAN HONDA MOTOR CO., INC.
  
  Fig 9: Identifying Passenger's Under-Dash Fuse/Relay Box Connector A Terminals
  Courtesy of AMERICAN HONDA MOTOR CO., INC.
  
  Fig 10: Identifying Driver's Under-Dash Fuse/Relay Box Connector F Terminals
  Courtesy of AMERICAN HONDA MOTOR CO., INC.
With the passenger's multiplex control unit still disconnected, make these input tests at the connectors and the passenger's under-dash fuse/relay box sockets.
- 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 9.
  
  Fig 11: Passenger's Multiplex Control Unit Input Test Table (1 Of 2)
  Courtesy of AMERICAN HONDA MOTOR CO., INC.
Reconnect the passenger's multiplex control unit to the passenger's under-dash fuse/relay box, and perform the following input tests at the appropriate connectors on the passenger's under-dash fuse/relay box (see Fig 7 , Fig 8 , Fig 9 and Fig 10 ). For passenger's under-dash fuse/relay box connector socket location (see Component Locations ).
NOTE: All passenger lock knobs must be in the locked position, then unlocked and locked one at a time, or the test results will not be correct.
- 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 10.
  
  Fig 12: Passenger's Multiplex Control Unit Input Test Table (2 Of 2)
  Courtesy of AMERICAN HONDA MOTOR CO., INC.
Multiplex Control Unit, Door:
Remove the driver's multiplex control door unit, and disconnect its connector.
Inspect all the connector and socket terminals to be sure they are 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 12.
  
  Fig 13: Identifying Door Multiplex Control Unit Connector Terminals
  Courtesy of AMERICAN HONDA MOTOR CO., INC.
With the door unit 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 13.
  
  Fig 14: Door Multiplex Control Unit Input Test Table (1 Of 2)
  Courtesy of AMERICAN HONDA MOTOR CO., INC.
Reconnect the connectors to the door multiplex control unit, 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 14.
  
  Fig 15: Door Multiplex Control Unit Input Test Table (2 Of 2)
  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.