Special Tools Required

SCS Service Connector 07WAZ-001010A

1. Check the No. 9 (7.5A) fuse in the driver's underdash 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 inspection connector (A).
   Fig 1: Connecting The Special Tool To The Multiplex Control Inspection Connector

   Courtesy 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. Check self-diagnosis function Mode 1 for a diagnostic trouble code (DTC). 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 beep for 0.2 second.

   This means that you are in Mode 1 of the self-diagnosis function.

   • If the system enters Mode 1, go to step 5.
   • If the system does not enter Mode 1, see if the SCS circuit is working properly, go to step 6.
     Fig 2: MODE 1: IGNITION KEY LIGHT and BEEPER

     Courtesy of AMERICAN HONDA MOTOR CO., INC.
5. About 1 second after you go into self-diagnosis Mode 1, the ignition key light and beeper indicate the DTC, and repeat it every 3 seconds. If there is a code, it will blink/beep, pause, then repeat the code as long as the ignition switch is ON. If there is more than one DTC, the system will indicate them in ascending order, beginning from the DTC with the lowest numerical value.

   Does the ignition key light blink and the beeper beep? 

   1. YES  : There is a DTC, Count the blinks/beeps to find your DTC in the table, then go to step 9 and check the communication lines.
      Fig 3: DTC Index

      Courtesy of AMERICAN HONDA MOTOR CO., INC.
   2. NO  : If the system goes into Mode 1 as described in step 4, and there is no repeating DTC. Go to step  11.
6. Remove the special tool from the SCS connector.
7. Check for continuity between the No. 1 terminal of the inspection connector and the A 15 terminal in the driver's multiplex control unit fuse box connector.

   Is there continuity? 

   1. YES  : Go to step 8.
   2. NO  : Replace the driver's under-dash fuse/relay box, and recheck for DTC's.
8. Check for continuity between the No. 3 terminal of the inspection connector and body ground G401.

   Is there continuity? 

   1. YES  : If there is still no Mode 1 confirmation, replace the driver's multiplex control unit and try again.

      After replacing the driver's multiplex control unit the system confirms Mode 1 and there are no codes, go to step  12.

   2. NO  : Repair open in the wire, and recheck for DTC's.
9. With the ignition switch OFF, check for continuity according to the table.
   Fig 4: Communication Line Continuity Checking Table

   Courtesy of AMERICAN HONDA MOTOR CO., INC.

   Is there continuity? 

   1. YES  : Go to step 10.
   2. NO  : Check for an open in the wire.
10. Turn the ignition switch ON (II), and check for voltage between the communication line and ground.
    Fig 5: Checking Communication Line Voltage Table

    Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Does the voltage match the table? 

    1. YES  : Communication lines are OK. Go to step 11.
    2. NO  : Repair the line according to the following.
    • If the voltage is too high:
      • Check for a short to another wire with voltage.
      • Check for poor contact in the connector at each control unit connector to the wire.
    • If the voltage is too low:
      • Check for a short to ground or to another wire.
      • Check for poor connections at each control unit connector to the wire.
      • Faulty circuit in one of the multiplex control units connected to the wire.
    • If any one or all the control units are completely inoperative, perform the multiplex control unit input test (see CONTROL UNIT INPUT TEST ).
11. Shift to the sleep mode:
    • Turn the ignition switch OFF and remove the key.
    • Remove the special tool from the SCS connector.
    • Cancel the key-off operation timer in the power window system by opening and closing one of the doors.
    • Make sure the exterior lights are off. If you do not operate any switches related to the multiplex control units within 1 minute after meeting the above conditions, the system function shifts to the sleep mode. (All of the switches must be turned OFF except door lock knob switches). Go to step 12.
12. Confirm the sleep mode:
    • Check for voltage to ground on the BRN wire and PNK wire. There should battery voltage in the sleep mode.
    • Check the parasitic draw at the battery while shifting to sleep mode. Amperage should change from about 70 to 80 mA to less than 20 mA.
    • If the vehicle does not go into the sleep mode, carefully perform Mode 2 test (see step 14), and check for faulty input for example a key cylinder switch keeping the system awake.
13. Confirm the wake up mode.
    • When any switch in the multiplex system is turned on, it wakes up its related control unit which, in turn, wakes up the other units. After one minute it will return to sleep mode again if the switch is returned to the original position.
    • When the ignition switch is turned to ON (II), all of the multiplex control units wake up at the same time without "talking" to each other through the communication lines.

    If the wake up mode is confirmed on the first switch tested, and there is no problem with any other switch operation, the system is working correctly, Go to step 14.

    After confirming a problem in sleep mode, look in the following tables for the switch most closely related to the problem you may be having. Operate that switch and see if its control unit wakes up. Also use Mode 2 step 14 to confirm switch inputs.

    NOTE: If any control unit is faulty and will not wake up, several function (locks, windows, etc.) of the system will malfunction at the same time.

    In each table below, the control unit is followed by a list of the switches and input signals that can wake it up.

    Fig 6: Identifying Passenger's Multiplex Control Unit Switches & Inputs

    Courtesy of AMERICAN HONDA MOTOR CO., INC.