AIRBAG SYSTEM, Diagnostic DTC:B1905/74,B1906/74,B1907/74 and B1908/74

DTC Code DTC Name
B1905/74 Short in Front Pretensioner Squib LH Circuit
B1906/74 Open in Front Pretensioner Squib LH Circuit
B1907/74 Short to GND in Front Pretensioner Squib LH Circuit
B1908/74 Short to B+ in Front Pretensioner Squib LH Circuit

DESCRIPTION

The front pretensioner squib LH circuit consists of the airbag sensor assembly and front seat outer belt assembly LH.

The airbag sensor assembly uses this circuit to deploy the seat belt pretensioner when deployment conditions are met.

These DTCs are stored when a malfunction is detected in the front pretensioner squib LH circuit.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

Test Mode / Check Mode

B1905/74

Short in Front Pretensioner Squib LH Circuit

  • The airbag sensor assembly detects a line short in the front pretensioner squib LH circuit during primary check.

  • Front pretensioner squib LH malfunction

  • Airbag sensor assembly malfunction

  • Floor wire

  • Front seat outer belt assembly LH (Front pretensioner squib LH)

  • Airbag sensor assembly

Applies to check mode

B1906/74

Open in Front Pretensioner Squib LH Circuit

  • The airbag sensor assembly detects an open in the front pretensioner squib LH circuit.

  • Front pretensioner squib LH malfunction

  • Airbag sensor assembly malfunction

  • Floor wire

  • Front seat outer belt assembly LH (Front pretensioner squib LH)

  • Airbag sensor assembly

Applies to check mode

B1907/74

Short to GND in Front Pretensioner Squib LH Circuit

  • The airbag sensor assembly detects a short to ground in the front pretensioner squib LH circuit.

  • Front pretensioner squib LH malfunction

  • Airbag sensor assembly malfunction

  • Floor wire

  • Front seat outer belt assembly LH (Front pretensioner squib LH)

  • Airbag sensor assembly

Applies to check mode

B1908/74

Short to B+ in Front Pretensioner Squib LH Circuit

  • The airbag sensor assembly detects a short to B+ in the front pretensioner squib LH circuit.

  • Front pretensioner squib LH malfunction

  • Airbag sensor assembly malfunction

  • Floor wire

  • Front seat outer belt assembly LH (Front pretensioner squib LH)

  • Airbag sensor assembly

Applies to check mode

WIRING DIAGRAM

C249389C01

CAUTION / NOTICE / HINT

Note:

After turning the ignition switch off, waiting time may be required before disconnecting the cable from the negative (-) battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) battery terminal notices before proceeding with work.

Click hereClick hereClick hereClick here

Tip:

PROCEDURE

  1. CHECK CONNECTORS

    1. C241752C01

      *1

      Front Seat Outer Belt Assembly LH

      *2

      Airbag Sensor Assembly

      *3

      Floor Wire

      Turn the ignition switch off.

    2. Disconnect the cable from the negative (-) battery terminal.

      CAUTION:

      Wait at least 90 seconds after disconnecting the cable from the negative (-) 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.

      Tip:

      If the connectors are not properly connected, 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 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 connector locking 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.

    Result

    Proceed to

    OK

    NG
    NG

    REPLACE FLOOR WIRE

    OK

  2. CHECK FRONT SEAT OUTER BELT ASSEMBLY LH (FRONT PRETENSIONER SQUIB LH)

    1. C241759C03

      *1

      Front Seat Outer Belt Assembly LH

      *2

      Airbag Sensor Assembly

      *a

      Front view of wire harness connector

      (to Front Seat Outer Belt Assembly LH)

      Connect the connector to the airbag sensor assembly.

    2. Connect SST (resistance 2.1 Ω) to connector C.

      CAUTION:

      Never connect a 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 it.

      • Insert SST straight into the terminals of the connector.

    3. Connect the cable to the negative (-) battery terminal.

    4. Clear the DTCs stored in memory.

      Click here

      Body Electrical > SRS Airbag > Clear DTCs

    5. Turn the ignition switch off.

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

    7. Check for DTCs.

      Click here

      Body Electrical > SRS Airbag > Trouble Codes

      OK

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

      Tip:

      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.

    8. Turn the ignition switch off.

    9. Disconnect the cable from the negative (-) battery terminal.

      CAUTION:

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

    10. Disconnect SST from connector C.

    09843-18061

    Result

    Proceed to

    OK

    NG
    OK

    REPLACE FRONT SEAT OUTER BELT ASSEMBLY LH

    Click hereClick here

    NG

  3. CHECK FLOOR WIRE

    1. C241760C02

      *1

      Front Seat Outer Belt Assembly LH

      *2

      Airbag Sensor Assembly

      *3

      Floor Wire

      *a

      Front view of wire harness connector

      (to Front Seat Outer Belt Assembly LH)

      Disconnect the floor wire from the airbag sensor assembly.

    2. Check for a short to B+ in the circuit.

      1. Connect the cable to the negative (-) battery terminal.

      2. Turn the ignition switch to ON.

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

        Standard Voltage

        Tester Connection

        Condition

        Specified Condition

        L8-1 (L+) - Body ground

        Ignition switch ON

        Below 1 V

        L8-2 (L-) - Body ground

        Ignition switch ON

        Below 1 V

      4. Turn the ignition switch off.

      5. Disconnect the cable from the negative (-) battery terminal.

        CAUTION:

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

    3. Check for an open in the circuit.

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

        Standard Resistance

        Tester Connection

        Condition

        Specified Condition

        L8-1 (L+) - L8-2 (L-)

        Always

        Below 1 Ω

    4. 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

        L8-1 (L+) - Body ground

        Always

        1 MΩ or higher

        L8-2 (L-) - Body ground

        Always

        1 MΩ or higher

    5. Check for a short in the circuit.

      1. Release the activation prevention mechanism built into connector B.

        Click hereClick hereClick hereClick here

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

        Standard Resistance

        Tester Connection

        Condition

        Specified Condition

        L8-1 (L+) - L8-2 (L-)

        Always

        1 MΩ or higher

      3. Restore the released activation prevention mechanism of connector B to the original condition.

    Result

    Proceed to

    OK

    NG
    NG

    REPLACE FLOOR WIRE

    OK

  4. CHECK DTC

    1. C238245C01

      *1

      Front Seat Outer Belt Assembly LH

      *2

      Airbag Sensor Assembly

      Connect the connectors to the front seat outer belt assembly LH and airbag sensor assembly.

    2. Connect the cable to the negative (-) battery terminal.

    3. Clear the DTCs stored in memory.

      Click here

      Body Electrical > SRS Airbag > Clear DTCs

    4. Turn the ignition switch off.

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

    6. Check for DTCs.

      Click here

      Body Electrical > SRS Airbag > Trouble Codes

      OK

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

      Tip:

      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.

    Result

    Proceed to

    OK

    NG
    OK

    USE SIMULATION METHOD TO CHECK

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    NG

    REPLACE AIRBAG SENSOR ASSEMBLY

    Click hereClick here