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Home >> Lexus >> 2021 >> NX 300h Luxury >> Repair and Diagnosis >> Restraints >> Air Bag, SRS >> Airbag System - Diagnostic Codes (3 Of 3) & Symptom Tests >> Airbag System >> DTC B1825-56: Short in Side Squib LH Circuit; DTC B1826-56: Open in Side Squib LH Circuit; DTC B1827-56: Short to GND in Side Squib LH Circuit; DTC B1828-56: Short to B+ in Side Squib LH Circuit [10/2014 - 05/2019] >> Procedure

DTC B1825-56: Short in Side Squib LH Circuit; DTC B1826-56: Open in Side Squib LH Circuit; DTC B1827-56: Short to GND in Side Squib LH Circuit; DTC B1828-56: Short to B+ in Side Squib LH Circuit [10/2014 - 05/2019]: Procedure

  1. CHECK FRONT SEAT AIRBAG ASSEMBLY LH 
    1. Turn the power switch off.
      GTY510504Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *1 Front Seat Airbag Assembly LH
      *2 Airbag ECU Assembly
      *3 Connector C
      *4 SST
      *a Front view of wire harness connector
      (to Front Seat Airbag Assembly LH)
    2. Disconnect the cable from the negative (-) auxiliary battery terminal, and wait for at least 90 seconds.
    3. Disconnect the connector from the front seat airbag assembly LH.
    4. Connect the red wire side of SST (resistance: 2.1 Ω) to connector C.
      WARNING:

      Never connect the tester to the front seat airbag assembly LH 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 (-) auxiliary battery terminal, and wait for at least 2 seconds.
    6. Turn the power switch on (IG), and wait for at least 60 seconds.
    7. Clear the DTCs.

      Refer to DTC CHECK / CLEAR [10/2014 - 05/2019]

      Body Electrical > SRS Airbag > Clear DTCs 

    8. Turn the power switch off.
    9. Turn the power switch on (IG), and wait for at least 60 seconds.
    10. Check for DTCs.

      Refer to DTC CHECK / CLEAR [10/2014 - 05/2019]

      Body Electrical > SRS Airbag > Trouble Codes 

      Result

      Proceed to
      DTC B1825/56, B1826/56, B1827/56 or B1828/56 is not output.
      DTC B1825/56, B1826/56, B1827/56 or B1828/56 is output.

      HINT: 

      Codes other than DTC B1800/51, B1801/51, B1802/51 and B1803/51 may be output at this time, but they are not related to this check.

    11. Turn the power switch off.
    12. Disconnect the cable from the negative (-) auxiliary battery terminal, and wait for at least 90 seconds.
    13. Disconnect SST from connector C.

    Result: 

    DTC B1825/56, B1826/56, B1827/56 or B1828/56 is not output. 

    REPLACE FRONT SEAT AIRBAG ASSEMBLY LH. Refer to  REMOVAL [10/2014 - 05/2019] 

    Result: 

    DTC B1825/56, B1826/56, B1827/56 or B1828/56 is output. 

    See step  2

  2. CHECK CONNECTORS 
    1. Disconnect the connectors from the airbag ECU assembly.
    2. Check that the connectors (on the airbag ECU assembly side and front seat airbag assembly LH side) are not damaged.

      OK

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

      GTY371088Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *1 Front Seat Airbag Assembly LH
      *2 No. 2 Floor Wire
      *3 Airbag ECU Assembly

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPLACE NO. 2 FLOOR WIRE 

    Result: 

    OK 

    See step  3

  3. CHECK NO. 2 FLOOR WIRE 
    1. Connect the cable to the negative (-) auxiliary battery terminal, and wait for at least 2 seconds.
      GTY505671Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *1 Front Seat Airbag Assembly LH
      *2 No. 2 Floor Wire
      *3 Airbag ECU Assembly
      *4 Connector C
      *a Front view of wire harness connector
      (to Front Seat Airbag Assembly LH)
    2. Turn the power switch on (IG).
    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Switch Condition Specified Condition
      Qd1-1 (SFL+) - Body ground Power switch on (IG) Below 1 V
      Qd1-2 (SFL-) - Body ground Power switch on (IG) Below 1 V
    4. Turn the power switch off.
    5. Disconnect the cable from the negative (-) auxiliary 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
      Qd1-1 (SFL+) - Qd1-2 (SFL-) Always Below 1 Ω
    7. Release the activation prevention mechanism built into connector B.

      Refer to DIAGNOSIS SYSTEM [10/2014 - ]

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

      Standard Resistance

      Tester Connection Condition Specified Condition
      Qd1-1 (SFL+) - Qd1-2 (SFL-) Always 1 MΩ or higher
    9. Restore the released activation prevention mechanism of connector B to its original condition.
    10. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      Qd1-1 (SFL+) - Body ground Always 1 MΩ or higher
      Qd1-2 (SFL-) - Body ground Always 1 MΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPLACE NO. 2 FLOOR WIRE 

    Result: 

    OK 

    See step  4

  4. CHECK DTC 
    1. Connect the connectors to the front seat airbag assembly LH and airbag ECU assembly.
      GTY369758Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *1 Front Seat Airbag Assembly LH
      *2 Airbag ECU Assembly
    2. Connect the cable to the negative (-) auxiliary battery terminal, and wait for at least 2 seconds.
    3. Turn the power switch on (IG), and wait for at least 60 seconds.
    4. Clear the DTCs.

      Refer to DTC CHECK / CLEAR [10/2014 - 05/2019]

      Body Electrical > SRS Airbag > Clear DTCs 

    5. Turn the power switch off.
    6. Turn the power switch on (IG), and wait for at least 60 seconds.
    7. Check for DTCs.

      Refer to DTC CHECK / CLEAR [10/2014 - 05/2019]

      Body Electrical > SRS Airbag > Trouble Codes 

      Result

      Proceed to
      DTC B1825/56, B1826/56, B1827/56 or B1828/56 is not output
      DTC B1825/56, B1826/56, B1827/56 or B1828/56 is output

      HINT: 

      Codes other than DTC B1825/56, B1826/56, B1827/56 and B1828/56 may be output at this time, but they are not related to this check.

    Result: 

    DTC B1825/56, B1826/56, B1827/56 or B1828/56 is not output 

    USE SIMULATION METHOD TO CHECK. Refer to  DIAGNOSIS SYSTEM [10/2014 - ] 

    Result: 

    DTC B1825/56, B1826/56, B1827/56 or B1828/56 is output 

    REPLACE AIRBAG ECU ASSEMBLY. Refer to  REMOVAL [10/2014 - 05/2019]