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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". Refer 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.

Trouble symptom 

  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 the Illumination of the driver's seat belt warning light in the combination meter, and the passenger's seat belt warning light in the MFD, and the sounding of the buzzer.

    Do the driver's warning light and passenger's warning light blink and the buzzer sound while blinking?

    Yes:  Go to  2.

    No:  Go to  12.

  2. CHECK FUNCTION. 
    1. Wait until the buzzer sound stops in step 1. (For approximately six seconds after starting sounding)
    2. Connect and disconnect the seat belts of the driver's and passenger's.
    3. Check the Illumination of the driver's seat belt warning light in the combination meter and the passenger's seat belt warning light in the MFD.

    Do the seat belts warning light illuminate ↔ go off according to the operation?

    Yes:  Go to  3.

    No:  Go to  8.

  3. CHECK FUNCTION. 
    1. Wait until the buzzer sound stops in step 2. (For approximately six seconds after starting sounding)
    2. Start the engine, and set the vehicle speed at 20 km/h (12 MPH) or more.
    3. Check the seat belt warning lights of the driver's and the passenger's, and if the warning buzzer sounds.

    Do the driver's warning light and passenger's warning light blink and the buzzer sound while blinking?

    Yes:  Go to  4.

    No:  Go to  14.

  4. CHECK HARNESS. 
    1. Disconnect the negative terminal from the battery, and wait for 60 seconds or more.
      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:  Go to  5.

    No:  Repair or replace the harness.

  5. CHECK 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:  Go to  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:  Go to  7.

    No:  Replace the seat belt inner - front LH. Refer to SEAT BELT SYSTEM>FRONT SEAT BELT>REMOVAL>SEAT BELT OUTER - FRONT .

  7. CHECK COMBINATION METER. 

    Perform the self-diagnosis of combination meter. Refer to INSTRUMENTATION/DRIVER INFO>COMBINATION METER SYSTEM>OPERATION>SELF-DIAGNOSIS DISPLAY MODE .

    At the start of combination meter self diagnosis, did the buzzer sound and the seat belt warning light illuminate?

    Yes:  Replace the combination meter. There may be a reception failure of the combination meter.

    No:  Replace the combination meter. Refer to INSTRUMENTATION/DRIVER INFO>COMBINATION METER>REMOVAL .

  8. CHECK DATA MONITOR. 
    1. Sit in the passenger's seat.
    2. Using the Subaru Select Monitor, select «Data monitor» to display data of «Passenger seat seat-belt wearing state».
      NOTE: For detailed operation procedures, refer to "Application help".
    3. Fasten and detach the passenger's side seat belt buckle, and read the data of the seat belt switch. Refer to COMBINATION METER (DIAGNOSTICS)>READ CURRENT DATA>LIST .

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

    Yes:  Go to  12.

    No:  Go to  9.

  9. CHECK AIRBAG SYSTEM AND OCCUPANT DETECTION SYSTEM. 

    Perform the check in accordance with the diagnostic procedure DTC B1650 of the airbag system. Refer to OCCUPANT DETECTION SYSTEM (DIAGNOSTICS)>DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)>DTC B1650 OCCUPANT DETECTION SYSTEM MALFUNCTION .

    Is the inspection result normal?

    Yes:  Go to  10.

    No:  Repair or replace with new parts according to DTC B1650.

  10. CHECK BUCKLE SWITCH RH. 

    Perform the check in accordance with the diagnostic procedure DTC B1655 of the occupant detection system. Refer to OCCUPANT DETECTION SYSTEM (DIAGNOSTICS)>DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)>DTC B1655 FRONT BUCKLE SWITCH RH FAILURE .

    Is the inspection result normal?

    Yes:  Go to  11.

    No:  Repair or replace with new parts according to DTC B1655.

  11. CHECK AIRBAG CONTROL MODULE AND COMBINATION METER. 

    Check the airbag control module, occupant detection sensor and seat belt buckle switch RH. Perform the check in accordance with the diagnostic procedure DTC B16F1 of the airbag system. Refer to AIRBAG SYSTEM (DIAGNOSTICS)>DIAGNOSTIC CHART WITH TROUBLE CODE>DTC B16F1 PASSENGER'S SEAT BELT WARNING FAILURE .

    Is the inspection result normal?

    Yes:  Replace the combination meter. Refer to INSTRUMENTATION/DRIVER INFO>COMBINATION METER>REMOVAL .

    No:  Repair or replace with new parts according to DTC B16F1.

  12. 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. 23 (+) - Chassis ground (-):

    Is the voltage 10 V or more?

    Yes:  Go to  13.

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

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

      Connector & terminal 

      (i122) No. 21 - Chassis ground:

    Is the resistance less than 10 Ω?

    Yes:  Go to  14.

    No:  Repair or replace the harness.

  14. 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. 12 - (i10) No. 28:

    Is the resistance less than 10 Ω?

    Yes:  Go to  15.

    No:  Repair or replace the harness.

  15. 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 case assembly.

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