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Home >> Toyota >> 2021 >> Highlander LE, 4WD >> Repair and Diagnosis >> Restraints >> Air Bag, SRS >> Airbag System - Diagnostic Codes (3 Of 7) >> Airbag System >> DTC B0050-00: Driver Seat Belt Sensor Circuit Undetermined Failure [11/2023 - ] >> Procedure

DTC B0050-00: Driver Seat Belt Sensor Circuit Undetermined Failure [11/2023 - ]: Procedure

  1. CHECK CONNECTION OF CONNECTORS 

    Pre-procedure1

    1. Turn the ignition switch off.
    2. Disconnect the cable from the negative (-) auxiliary battery terminal, and wait for at least 60 seconds.

      Procedure1

    3. Check that the connectors are properly connected to the airbag sensor assembly and front seat inner belt assembly LH.

      OK

      The connectors are properly connected.

      Result

      Proceed to
      OK
      NG

      Post-procedure1

    4. None

    Result: 

    NG 

    CONNECT CONNECTORS PROPERLY 

    Result: 

    OK 

    See step  2

  2. CHECK CONNECTORS 

    Pre-procedure1

    1. Disconnect the airbag sensor assembly connector.
      GTY972961Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *1 Front Seat Inner Belt Assembly LH
      *2 Airbag Sensor Assembly
      *3 Wire Harness
    2. Disconnect the front seat inner belt assembly LH connector.

      Procedure1

    3. Check that the terminals of the connectors are not deformed or damaged.

      OK

      The terminals are not deformed or damaged.

      Result

      Proceed to
      OK
      NG

      Post-procedure1

    4. None

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  3

  3. INSPECT FRONT SEAT INNER BELT ASSEMBLY LH 

    Pre-procedure1

    1. Remove the front seat inner belt assembly LH.

      Refer to REMOVAL [11/2023 - ]

      Procedure1

    2. Inspect the front seat inner belt assembly LH.
      GTY1055206Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *1 Front Seat Inner Belt Assembly LH *2 Auxiliary Battery
      *a Component without harness connected
      (Front Seat Inner Belt Assembly LH)      		 *b Tester

      Standard Current

      Tester Connection Condition Specified Condition
      Tester positive (+) - 1
      Tester negative (-) - Auxiliary battery negative (-)      		 Seat belt fastened 12.0 to 18.0 mA
      Seat belt not fastened 4.0 to 7.0 mA

      Result

      Proceed to
      OK
      NG

      Post-procedure1

    3. None

    Result: 

    NG 

    REPLACE FRONT SEAT INNER BELT ASSEMBLY LH. Refer to  REMOVAL [11/2023 - ] 

    Result: 

    OK 

    See step  4

  4. CHECK HARNESS AND CONNECTOR (CHECK FOR OPEN IN THE CIRCUIT) 

    Pre-procedure1

    1. Using a service wire, connect terminals 30 (LBE+) and 24 (GNDL) of connector B.
      GTY1178113Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *1 Front Seat Inner Belt Assembly LH
      *2 Airbag Sensor Assembly
      *3 Wire Harness
      *4 Service Wire
      *a Front view of wire harness connector
      (to Front Seat Inner Belt Assembly LH)
      *b Front view of wire harness connector
      (to Airbag Sensor Assembly)
      NOTE:

      Do not forcibly insert the service wire into the terminals of the connector when connecting a service wire.

      Procedure1

    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      M70-2 (LBE+) - M70-1 (LBE-) Always Below 1 Ω

      Result

      Proceed to
      OK
      NG

      Post-procedure1

    3. Disconnect the service wire from connector B.

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  5

  5. CHECK HARNESS AND CONNECTOR (CHECK FOR SHORT TO GROUND IN THE CIRCUIT) 
    1. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      M70-2 (LBE+) - Body ground Always 1 MΩ or higher
      M70-1 (LBE-) - Body ground Always 1 MΩ or higher
      GTY1177979Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *1 Front Seat Inner Belt Assembly LH
      *2 Airbag Sensor Assembly
      *3 Wire Harness
      *a Front view of wire harness connector
      (to Front Seat Inner Belt Assembly LH)

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  6

  6. CHECK HARNESS AND CONNECTOR (CHECK FOR SHORT TO +B IN THE CIRCUIT) 

    Pre-procedure1

    1. Connect the cable to the negative (-) auxiliary battery terminal, and wait for at least 2 seconds.
    2. Turn the ignition switch to ON.

      Procedure1

    3. Measure the voltage according to the value(s) in the table below.
      GTY1177979Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *1 Front Seat Inner Belt Assembly LH
      *2 Airbag Sensor Assembly
      *3 Wire Harness
      *a Front view of wire harness connector
      (to Front Seat Inner Belt Assembly LH)

      Standard Voltage

      Tester Connection Condition Specified Condition
      M70-2 (LBE+) - Body ground Ignition switch ON Below 1 V
      M70-1 (LBE-) - Body ground Ignition switch ON Below 1 V

      Result

      Proceed to
      OK
      NG

      Post-procedure1

    4. Turn the ignition switch off.
    5. Disconnect the cable from the negative (-) auxiliary battery terminal, and wait for at least 60 seconds.

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  7

  7. CLEAR DTC 

    Pre-procedure1

    1. Connect the airbag sensor assembly connector.
      GTY972931Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *1 Front Seat Inner Belt Assembly LH
      *2 Airbag Sensor Assembly
      *3 Wire Harness
    2. Connect the front seat inner belt assembly LH connector.
    3. Connect the cable to the negative (-) auxiliary battery terminal, and wait for at least 2 seconds.
    4. Turn the ignition switch to ON, and wait for at least 60 seconds.

      Procedure1

    5. Clear the DTCs stored in memory.

      Body Electrical > SRS Airbag > Clear DTCs 

      Result

      Proceed to
      NEXT

      Post-procedure1

    6. Turn the ignition switch off.

    Result: 

    NEXT 

    See step  8

  8. CHECK DTC 

    Pre-procedure1

    1. Turn the ignition switch to ON, and wait for at least 60 seconds.

      Procedure1

    2. Check for DTCs.

      Body Electrical > SRS Airbag > Trouble Codes 

      Result

      Result Proceed to
      B0050-00 is output A
      B0050-00 is not output B

      HINT: 

      Codes other than DTC B0050-00 may be output at this time, but they are not related to this check.

      Post-procedure1

    3. None

    Result: 

    A 

    REPLACE AIRBAG SENSOR ASSEMBLY. Refer to  REMOVAL [11/2023 - ] 

    Result: 

    B 

    USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [12/2019 - ] 

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