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To Enter Mode 1

  1. Check the No. 9 (10A) fuse in the driver's under-dash fuse/relay box and the No. 13 (7.5A) fuse in the Passenger's under-dash fuse/relay box.

    Are the fuses OK? 

    1. YES:  Go to step 2.
    2. NO:  Find and repair the cause of the blown fuse.
  2. Connect the special tool to the multiplex control system (MPCS) inspection connector (A).
    Fig 1: Connecting Special Tool To MPCS Inspection Connector
    G01520231Courtesy of AMERICAN HONDA MOTOR CO., INC.
  3. Turn the ignition switch ON (II). If the driver's seat belt is unbuckled, the seat belt reminder will beep five times.
  4. After about 5 seconds, the ignition key light should come on and the beeper should beep for 2 seconds, then go off for 0.2 second, then blink and deep for 0.2 second. This indicated that the system is in Mode 1.
    Fig 2: Identifying MODE 1: Ignition Key Light and Beeper
    G01520232Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Did the multiplex system enter Mode 1? 

    1. YES:  Go to step 5.
    2. NO:  Go to step  6.
  5. Check for a DTC.
    • If there is no DTCs present:

      The ignition key light and beeper will not blink/beep again after the Mode 1 indication.

    • If there are DTC(s) present:

      About 1 second after entering Mode 1, the ignition key light and beeper indicate the DTC(s), then repeat it every 3 seconds. If there is more than one DTC, the system will indicate them in ascending order.

    Is there a DTC present? 

    1. YES:  Follow the procedure in the chart below.
    2. NO:  Go to Mode 2 (see Mode 2  ).
    Fig 3: Identifying DTC Chart
    G01520233Courtesy of AMERICAN HONDA MOTOR CO., INC.
  6. Remove the special tool from the MPCS inspection connector.
  7. Remove driver's multiplex control unit from the driver's under-dash fuse/relay box.
  8. Check for voltage between the No. 12 terminal of the driver's fuse/relay box socket and body ground.
    Fig 4: Checking Voltage Between No. 12 Terminal Of Driver's Fuse/Relay Box Socket & Body Ground
    G01520234Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there battery voltage? 

    1. YES:  Go to step 9.
    2. NO:  Replace the driver's under-dash fuse/relay box.
  9. Turn ignition switch ON (II).
  10. Check for voltage between No. 24 terminal of the driver's fuse/relay box socket and body ground.
    Fig 5: Checking Voltage Between No. 24 Terminal Of Driver's Fuse/Relay Box Socket & Body Ground
    G01520235Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there battery voltage? 

    1. YES:  Go to step 11.
    2. NO:  Repair an open in the wire between No. 13 fuse in the passenger's under-dash fuse/relay box and the driver's under-dash fuse/relay box socket.
  11. Check for continuity between No. 14 terminal of the driver's under-dash fuse/relay box socket and body ground.
    Fig 6: Checking Continuity Between No. 14 Terminal Of Driver's Under-Dash Fuse/Relay Box Socket & Body Ground
    G01520236Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    1. YES:  Go to step 12.
    2. NO:  Repair an open in the wire between driver's multiplex control unit and body ground. If the wire is OK, check for poor ground at G401.
  12. Check for continuity between No. 11 terminal of the driver's multiplex control unit connector B (22P) and body ground.
    Fig 7: Checking Continuity Between No. 11 Terminal Of Driver's Multiplex Control Unit Connector B (22P) & Body Ground
    G01520237Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    1. YES:  Go to step 13.
    2. NO:  Repair an open in the wire between driver's multiplex control unit connector B and ground. If the wire is OK, check for door ground at G501.
  13. Check for continuity between No. 1 terminal of the MPCS inspection connector and the No. 15 terminal of the driver's under-dash fuse/relay box socket.
    Fig 8: Checking Continuity Between No. 1 Terminal Of MPCS Inspection Connector & No. 15 Terminal Of Driver's Under-Dash Fuse/Relay Box Socket
    G01520238Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    1. YES:  Go to step 14.
    2. NO:  Repair an open in the wire between the MPCS inspection connector and the driver's under-dash fuse/relay box. If the wire is OK, replace the driver's under-dash fuse/relay box.
  14. Check for continuity between No. 3 terminal of the MPCS inspection connector and body ground.
    Fig 9: Checking Continuity Between No. 3 Terminal Of MPCS Inspection Connector & Body Ground
    G01520239Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    1. YES:  If there is still no Mode 1 indication, replace the driver's multiplex control unit and recheck the symptom.
    2. NO:  Repair an open in the wire between the inspection connector and body ground. If the wire is OK, check for a poor ground at G401.
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