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Seat Belt Warning System: Inspection

CAUTION:
  • Before handling the airbag system components, refer to "CAUTION" of "General Description" in "AIRBAG SYSTEM". Ref. to AIRBAG SYSTEM>General Description>CAUTION .
  • When inspecting the airbag main harness, disconnect the connectors of the driver's airbag module, passenger's airbag module and knee airbag module for safety reasons.
  • When inspecting the airbag rear harness, disconnect the side airbag module connector, curtain airbag module connector and seat belt pretensioner connector for safety reasons.
  1. CHECK FUNCTION  .
    1. Sit on the driver's seat and passenger's seat and disconnect the seat belts of the both.
    2. Turn the ignition switch to ON (engine OFF).
    3. Check if the driver's seat belt warning light in the combination meter and the passenger's seat belt warning light in the MFD blink, and if the buzzer sounds.

    Do the driver's and passenger's warning lights blink?

    Does the buzzer sound?

    Yes:  2

    No: 

    • For malfunction of the driver's seat belt warning light, go to the next step.  4
    • For malfunction of the passenger's seat belt warning light, go to the next step.  10
    • If no buzzer sounds, go to the next step.  7
  2. CHECK FUNCTION  .
    1. Wait until the buzzer sound in step  1 stops.
    2. Start the engine, and set the vehicle speed at 20 km/h (12 MPH) or more.
    3. Check if the driver's seat belt warning light in the combination meter and the passenger's seat belt warning light in the MFD blink, and if the buzzer sounds.

    Do the driver's and passenger's warning lights blink?

    Does the buzzer sound?

    Yes:  Seat belt warning system is normal.

    No:  3

  3. CHECK COMBINATION METER VEHICLE SPEED INPUT  .
    1. Using Subaru Select Monitor, select [Data Monitor] and display the data of [Vehicle speed data].
      NOTE: For detailed operation procedures, refer to "Application help".
    2. Start the engine and set the vehicle speed at 20 km/h (12 MPH) as in driving condition referring to the speedometer display.
    3. Read the reading of the recognized vehicle speed in meter. Ref. to COMBINATION METER (DIAGNOSTICS)>Data Monitor>OPERATION .

    Is the recognized vehicle speed less than 15 km/h (9 MPH)?

    Yes:  Replace the combination meter. Ref. to INSTRUMENTATION/DRIVER INFO>Combination Meter>REMOVAL .

    No:  Perform the diagnosis for LAN system.

  4. CHECK DRIVER's SIDE HARNESS  .
    1. Disconnect the negative terminal from the battery, and wait for 60 seconds or more. Ref. to NOTE>NOTE>BATTERY .
      NOTE: For model with battery sensor, disconnect the ground terminal from battery sensor.
    2. Disconnect the connectors of the combination meter and the seat belt buckle switch LH.
    3. Check for short circuit to battery, open circuit and short circuit to ground between the combination meter and the seat belt buckle switch LH.

    Connector & terminal 

    (i10) No. 15 - (R108) No. 1:

    Is the harness normal?

    Yes:  5

    No:  Repair or replace the harness.

  5. CHECK DRIVER's SIDE HARNESS  .

    Measure the resistance between the seat belt buckle switch LH and chassis ground.

    Connector & terminal 

    (R108) No. 2 - Chassis ground:

    Is the resistance less than 10 Ω?

    Yes:  6

    No:  Repair or replace the harness.

  6. CHECK SEAT BELT BUCKLE SWITCH LH  .

    Measure the resistance between the connector terminals of the driver's seat belt switch when the driver's seat belt is fastened and detached.

    Connector & terminal 

    (R108) No. 1 - (R108) No. 2:

    Is the resistance when the belt is fastened 1 MΩ or more, and less than 10 Ω when the belt is detached?

    Yes:  7

    No:  Replace the seat belt inner - front LH. Ref. to SEAT BELT SYSTEM>Front Seat Belt>REMOVAL>SEAT BELT OUTER - FRONT .

  7. CHECK POWER SUPPLY OF COMBINATION METER  .
    1. Connect the battery ground terminal. Ref. to NOTE>NOTE>BATTERY .
    2. Disconnect the connector of combination meter.
    3. Turn the ignition switch to ON.
    4. Measure the voltage between the ignition power supply and the combination meter.

    Connector & terminal 

    (i10) No. 20 - Chassis ground:

    Is the voltage 10 V or more?

    Yes:  8

    No:  Check the harness for open or short between the power supply and the meter.

  8. CHECK GROUND CIRCUIT OF COMBINATION METER  .
    1. Turn the ignition switch to OFF.
    2. Measure the resistance between the combination meter and the chassis ground.

      Connector & terminal 

      (i10) No. 38 - Chassis ground:

    Is the resistance less than 10 Ω?

    Yes:  9

    No:  Repair or replace the harness.

  9. CHECK COMBINATION METER  .

    Check if the seat belt warning light illuminates and if the buzzer sounds using the system operation check mode or the self-diagnosis display mode for the combination meter.

    Does the driver's seat belt warning light illuminate and the buzzer sound?

    Yes:  Function is normal.

    Temporary poor contact.

    No:  Replace the combination meter. Ref. to INSTRUMENTATION/DRIVER INFO>Combination Meter>REMOVAL .

  10. CHECK DATA MONITOR  .
    1. Sit in the passenger's seat.
    2. Using Subaru Select Monitor, select [Data Monitor] and display the data of [Passenger side seat belt state].
    3. Fasten and detach the passenger's side seat belt buckle, and read the data of the seat belt switch. Ref. to COMBINATION METER (DIAGNOSTICS)>DATA MONITOR .

    Does the seat belt switch display turn ON ←→ OFF according to the operation of the seat belt buckle?

    Yes:  11

    No:  Read the diagnostic trouble code (DTC) and perform the diagnosis according to DTC B1650, B1655 or B16F1.

  11. CHECK MFD POWER SUPPLY VOLTAGE  .
    1. Disconnect the MFD connector.
    2. Turn the ignition switch to ON.
    3. Measure the voltage between the ignition power supply and the MFD.

      Connector & terminal 

      (i122) No. 3 (+) - Chassis ground (-):

    Is the voltage 10 V or more?

    Yes:  12

    No:  Check the harness for open or short between the fuse and MFD.

  12. CHECK MFD GROUND CIRCUIT  .
    1. Turn the ignition switch to OFF.
    2. Measure the resistance between MFD and chassis ground.

      Connector & terminal 

      (i122) No. 2 - Chassis ground:

    Is the resistance less than 10 Ω?

    Yes:  13

    No:  Repair or replace the harness.

  13. CHECK HARNESS BETWEEN MFD AND COMBINATION METER  .
    1. Disconnect the harness of the MFD and the combination meter.
    2. Measure the resistance between MFD and combination meter.

      Connector & terminal 

      (i122) No. 9 - (i10) No. 28:

    Is the resistance less than 10 Ω?

    Yes:  14

    No:  Repair or replace the harness.

  14. CHECK COMMUNICATION STATUS BETWEEN MFD AND COMBINATION METER  .
    1. Remove the MFD, and install a properly operating MFD (new MFD).
    2. Connect the connector and then turn the ignition switch to ON.

    Is the MFD properly displayed?

    Yes:  Replace the MFD.

    No:  Replace the combination meter. Ref. to INSTRUMENTATION/DRIVER INFO>Combination Meter>REMOVAL .

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