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Home >> Lexus >> 2021 >> GX 460 Luxury >> Repair and Diagnosis >> Restraints >> Air Bag, SRS >> Supplemental Restraint System (Diagnostic Codes) (3 Of 3) & Symptom Tests >> Airbag System >> DTC B1900: Short in P/T Squib (RH) Circuit; DTC B1901: Open in P/T Squib (RH) Circuit; DTC B1902: Short in P/T Squib (RH) Circuit (to Ground); DTC B1903: Short in P/T Squib (RH) Circuit (to +B) [08/2019 - ] >> Procedure

DTC B1900: Short in P/T Squib (RH) Circuit; DTC B1901: Open in P/T Squib (RH) Circuit; DTC B1902: Short in P/T Squib (RH) Circuit (to Ground); DTC B1903: Short in P/T Squib (RH) Circuit (to +B) [08/2019 - ]: Procedure

  1. CHECK FRONT SEAT OUTER BELT RH (FRONT PRETENSIONER SQUIB RH) 
    1. Turn the engine switch off.
      GTY625330Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.
    3. Disconnect the connectors from the front seat outer belt RH.
    4. Connect the white wire side of SST (resistance: 2.1 Ω) to connector C.
      WARNING:

      Never connect the tester to the front seat outer belt RH (front pretensioner squib RH) for measurement, as this may lead to a serious injury due to airbag deployment.

      NOTE:
      • Do not forcibly insert SST into the terminals of the connector when connecting SST.
      • Insert SST straight into the terminals of the connector.
      • SST: 09843-18061 
    5. Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds.
    6. Turn the engine switch on (IG), and wait for at least 60 seconds.
    7. Clear the DTCs (Refer to DTC CHECK / CLEAR [08/2019 - ] ).
    8. Turn the engine switch off.
    9. Turn the engine switch on (IG), and wait for at least 60 seconds.
    10. Check for DTCs (Refer to DTC CHECK / CLEAR [08/2019 - ] ).

      OK

      DTC B1900, B1901, B1902 or B1903 is not output.

      HINT: 

      Codes other than DTC B1900, B1901, B1902 and B1903 may be output at this time, but they are not related to this check.

      TEXT IN ILLUSTRATION

      *1 Front Pretensioner Squib RH
      *2 Center Airbag Sensor
      *3 Connector C
      *4 SST
      *a Front view of wire harness connector
      (to Front Pretensioner Squib RH)

    Result: 

    OK 

    REPLACE FRONT SEAT OUTER BELT ASSEMBLY RH 

    (Refer to REMOVAL [08/2019 - ] )

    Result: 

    NG 

    See step  2

  2. CHECK CONNECTOR 
    1. Turn the engine switch off.
    2. Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.
    3. Disconnect SST from connector C.
    4. Check that the floor wire connector (on the front seat outer belt RH side) is not damaged.

      OK

      The lock button is not disengaged, and the claw of the lock is not deformed or damaged.

      GTY646273Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      TEXT IN ILLUSTRATION

      *1 Front Pretensioner Squib RH
      *2 Center Airbag Sensor

    Result: 

    NG 

    REPLACE FLOOR WIRE 

    Result: 

    OK 

    See step  3

  3. CHECK FLOOR WIRE (FRONT PRETENSIONER SQUIB RH CIRCUIT) 
    1. Disconnect the connectors from the center airbag sensor.
      GTY641233Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds.
    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Switch Condition Specified Condition
      Q2-1 (R+) - Body ground Engine switch on (IG) Below 1 V
      Q2-2 (R-) - Body ground Engine switch on (IG) Below 1 V
    4. Turn the engine switch off.
    5. Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.
    6. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      Q2-1 (R+) - Q2-2 (R-) Always Below 1 Ω
    7. Release the activation prevention mechanism built into connector B (Refer to DIAGNOSIS SYSTEM [08/2019 - ] ).
    8. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      Q2-1 (R+) - Q2-2 (R-) Always 1 MΩ or higher
      Q2-1 (R+) - Body ground Always 1 MΩ or higher
      Q2-2 (R-) - Body ground Always 1 MΩ or higher
      TEXT IN ILLUSTRATION

      *1 Front Pretensioner Squib RH
      *2 Floor Wire
      *3 Center Airbag Sensor
      *4 Connector C
      *a Front view of wire harness connector
      (to Front Pretensioner Squib RH)

    Result: 

    NG 

    REPLACE FLOOR WIRE 

    Result: 

    OK 

    See step  4

  4. CHECK CENTER AIRBAG SENSOR 
    1. Connect the connectors to the front seat outer belt RH and center airbag sensor.
      GTY409911Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds.
    3. Turn the engine switch on (IG), and wait for at least 60 seconds.
    4. Clear the DTCs stored in memory (Refer to DTC CHECK / CLEAR [08/2019 - ] ).
    5. Turn the engine switch off.
    6. Turn the engine switch on (IG), and wait for at least 60 seconds.
    7. Check for DTCs (Refer to DTC CHECK / CLEAR [08/2019 - ] ).

      OK

      DTC B1900, B1901, B1902 or B1903 is not output.

      HINT: 

      Codes other than DTC B1900, B1901, B1902 and B1903 may be output at this time, but they are not related to this check.

      TEXT IN ILLUSTRATION

      *1 Front Pretensioner Squib RH
      *2 Center Airbag Sensor

    Result: 

    OK 

    USE SIMULATION METHOD TO CHECK 

    (Refer to DIAGNOSIS SYSTEM [08/2019 - ] )

    Result: 

    NG 

    REPLACE CENTER AIRBAG SENSOR ASSEMBLY 

    (Refer to REMOVAL [08/2015 - ] )

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