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Home >> Lexus >> 2012 >> CT 200h F Sport >> Repair and Diagnosis >> Restraints >> Air Bag, SRS >> Airbag System (Diagnostic Codes (B1650/32 - B1905/74) & Symptom Tests) >> Airbag System >> DTC B1905/74: Short in Front Pretensioner Squib LH Circuit; DTC B1906/74: Open in Front Pretensioner Squib LH Circuit; DTC B1907/74: Short to GND in Front Pretensioner Squib LH Circuit; DTC B1908/74: Short to B+ in Front Pretensioner Squib LH Circuit >> Procedure

DTC B1905/74: Short in Front Pretensioner Squib LH Circuit; DTC B1906/74: Open in Front Pretensioner Squib LH Circuit; DTC B1907/74: Short to GND in Front Pretensioner Squib LH Circuit; DTC B1908/74: Short to B+ in Front Pretensioner Squib LH Circuit: Procedure

  1. CHECK CONNECTORS 
    1. Turn the power switch off.
      Fig 1: Identifying curtain shield airbag assembly LH and center airbag sensor assembly
      GTY230762Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Disconnect the cable from the negative (-) auxiliary battery terminal.
      WARNING:

      Wait at least 90 seconds after disconnecting the cable from the negative (-) auxiliary battery terminal to disable the SRS system.

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

      OK

      The connectors are properly connected.

      HINT: 

      If the connectors are not connected securely, reconnect the connectors and proceed to the next inspection.

    4. Disconnect the connectors from the front seat outer belt assembly LH and airbag sensor assembly.
    5. Check that the terminals of the connectors are not damaged.

      OK

      The terminals are not deformed or damaged.

    6. Check that the floor wire connector (on the front seat outer belt assembly LH side) is not damaged.

      OK

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

    7. Check that the short spring for the floor wire with the activation prevention mechanism is not deformed or damaged.

      OK

      The short spring is not deformed or damaged.

      TEXT IN ILLUSTRATION

      *1 Front Seat Outer Belt Assembly LH
      *2 Airbag Sensor Assembly
      *3 Floor Wire

    NG → REPLACE FLOOR WIRE 

    OK: Go to next step 

  2. CHECK FRONT SEAT OUTER BELT ASSEMBLY LH (FRONT PRETENSIONER SQUIB LH) 
    1. Connect the connector to the airbag sensor assembly.
      Fig 2: Identifying P6 Connector Terminals
      GTY358511Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Connect SST (resistance 2.1 Ω) to connector C.
      WARNING:

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

      NOTE:
      • Do not forcibly insert SST into the terminals of the connector when connecting.
      • Insert SST straight into the terminals of the connector.
      • SST: 09843-18061 
    3. Connect the cable to the negative (-) auxiliary battery terminal.
    4. Turn the power switch on (IG), and wait for at least 60 seconds.
    5. Clear the DTCs stored in memory. Refer to DTC CHECK / CLEAR .
    6. Turn the power switch off.
    7. Turn the power switch on (IG), and wait for at least 60 seconds.
    8. Check for DTCs. Refer to DTC CHECK / CLEAR .

      OK

      DTC B1905/74, B1906/74, B1907/74 or B1908/74 is not output.

      TEXT IN ILLUSTRATION

      *1 Front Seat Outer Belt Assembly LH
      *2 Airbag Sensor Assembly
      *3 Connector C
      *a Front view of wire harness connector
      (to Front Seat Outer Belt Assembly LH)

      HINT: 

      Codes other than DTCs B1905/74, B1906/74, B1907/74 and B1908/74 may be output at this time, but they are not related to this check.

    NG → See step   3 

    OK → See step   7 

  3. CHECK FLOOR WIRE (FRONT PRETENSIONER SQUIB LH CIRCUIT) 
    1. Turn the power switch off.
      Fig 3: Identifying P6 Connector Terminals
      GTY349768Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Disconnect the cable from the negative (-) auxiliary battery terminal.
      WARNING:

      Wait at least 90 seconds after disconnecting the cable from the negative (-) auxiliary battery terminal to disable the SRS system.

    3. Disconnect SST from connector C.
    4. Disconnect the floor wire from the airbag sensor assembly.
    5. Check for a short to B+ in the circuit.
      1. Connect the cable to the negative (-) auxiliary battery terminal.
      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
        P6-1 (L+) - Body ground Power switch on (IG) Below 1 V
        P6-2 (L-) - Body ground Power switch on (IG) Below 1 V
    6. Check for an open in the circuit.
      1. Turn the power switch off.
      2. Disconnect the cable from the negative (-) auxiliary battery terminal.
        WARNING:

        Wait at least 90 seconds after disconnecting the cable from the negative (-) auxiliary battery terminal to disable the SRS system.

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

        Standard Resistance

        Tester Connection Condition Specified Condition
        P6-1 (L+) - P6-2 (L-) Always Below 1 Ω
    7. Check for a 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
        P6-1 (L+) - Body ground Always 1 MΩ or higher
        P6-2 (L-) - Body ground Always 1 MΩ or higher
    8. Check for a short in the circuit.
      1. Release the activation prevention mechanism built into connector B. Refer to DIAGNOSIS SYSTEM .
      2. Measure the resistance according to the value(s) in the table below.

        Standard Resistance

        Tester Connection Condition Specified Condition
        P6-1 (L+) - P6-2 (L-) Always 1 MΩ or higher
        TEXT IN ILLUSTRATION

        *1 Front Seat Outer Belt Assembly LH
        *2 Airbag Sensor Assembly
        *3 Floor Wire
        *4 Connector C
        *a Front view of wire harness connector
        (to Front Seat Outer Belt Assembly LH)

    NG → REPLACE FLOOR WIRE 

    OK: Go to next step 

  4. CHECK AIRBAG SENSOR ASSEMBLY 
    1. Restore the released activation prevention mechanism of connector B to the original condition.
      Fig 4: Identifying Center Airbag Sensor Assembly
      GTY215898Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Connect the connectors to the front seat outer belt assembly LH and airbag sensor assembly.
    3. Connect the cable to the negative (-) auxiliary battery terminal.
    4. Turn the power switch on (IG), and wait for at least 60 seconds.
    5. Clear the DTCs stored in memory. Refer to DTC CHECK / CLEAR .
    6. Turn the power switch off.
    7. Turn the power switch on (IG), and wait for at least 60 seconds.
    8. Check for DTCs. Refer to DTC CHECK / CLEAR .

      OK

      DTC B1905/74, B1906/74, B1907/74 or B1908/74 is not output.

      TEXT IN ILLUSTRATION

      *1 Front Seat Outer Belt Assembly LH
      *2 Airbag Sensor Assembly

      HINT: 

      Codes other than DTCs B1905/74, B1906/74, B1907/74 and B1908/74 may be output at this time, but they are not related to this check.

    NG → See step   6 

    OK → See step   5 

  5. USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING 
  6. REPLACE AIRBAG SENSOR ASSEMBLY. Refer to  REMOVAL 
  7. REPLACE FRONT SEAT OUTER BELT ASSEMBLY LH. Refer to  REMOVAL 
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