AIRBAG SYSTEM, Diagnostic DTC:B1905/74, B1906/74, B1907/74, 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 center airbag sensor assembly and the front seat outer belt LH.

This circuit instructs the SRS to deploy when deployment conditions are met.

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

DTC Code Detection Condition Trouble Area
B1905/74

One of the following conditions is met:


  • The center airbag sensor assembly receives a line short circuit signal 5 times in the front pretensioner squib LH circuit during primary check.

  • Front pretensioner squib LH malfunction

  • Center airbag sensor assembly malfunction

  • No. 2 floor wire

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

  • Center airbag sensor assembly
B1906/74

One of the following conditions is met:


  • The center airbag sensor assembly receives an open circuit signal in the front pretensioner squib LH circuit for 2 seconds.

  • Front pretensioner squib LH malfunction

  • Center airbag sensor assembly malfunction

  • No. 2 floor wire

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

  • Center airbag sensor assembly
B1907/74

One of the following conditions is met:


  • The center airbag sensor assembly receives a short circuit to ground signal in the front pretensioner squib LH circuit for 0.5 seconds.

  • Front pretensioner squib LH malfunction

  • Center airbag sensor assembly malfunction

  • No. 2 floor wire

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

  • Center airbag sensor assembly
B1908/74

One of the following conditions is met:


  • The center airbag sensor assembly receives a short circuit to B+ signal in the front pretensioner squib LH circuit for 0.5 seconds.

  • Front pretensioner squib LH malfunction

  • Center airbag sensor assembly malfunction

  • No. 2 floor wire

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

  • Center airbag sensor assembly

WIRING DIAGRAM

A001BILE02
*a Front Pretensioner Squib LH
*b Center Airbag Sensor Assembly

CAUTION / NOTICE / HINT

Note


  • After turning the engine 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 here.

  • When disconnecting the cable from the negative (-) battery terminal while performing repairs, some systems need to be initialized after the cable is reconnected Click here.

Tech Tips


  • Perform the simulation method by selecting "check mode" (signal check) with the intelligent tester Click here.

  • After selecting "check mode" (signal check), perform the simulation method by wiggling each connector of the airbag system or driving the vehicle on various types of roads Click here.

PROCEDURE


  1. CHECK FRONT SEAT OUTER BELT LH (FRONT PRETENSIONER SQUIB LH)

    A001E23E02
    *1 Center Airbag Sensor Assembly
    *2 Front Pretensioner Squib LH
    *3 Front view of wire harness connector: (to Front Pretensioner Squib LH)
    *4 Connector C

    1. Turn the engine switch off.

    2. Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.

    3. Disconnect the connectors from the front seat outer belt LH.

    4. Connect the white wire side of SST (resistance: 2.1 Ω) to connector C.

      CAUTION:

      Never connect the tester to the front seat outer belt LH (front pretensioner squib 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 negative (-) terminal cable to the battery, 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 Click here.

    8. Turn the engine switch off.

    9. Turn the engine switch on (IG), and wait for at least 60 seconds.

    10. Check for DTCs Click here.

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

      Tech Tips

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


    OK

    REPLACE FRONT SEAT OUTER BELT ASSEMBLY LH Click here

    NG

  2. CHECK CONNECTOR


    1. Turn the engine switch off.

    2. Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.

    3. Disconnect SST from connector C.

    4. Check that the No. 2 floor wire connector (on the front seat outer belt LH side) is not damaged.

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

    NG

    REPLACE NO. 2 FLOOR WIRE

    OK

  3. CHECK NO. 2 FLOOR WIRE (FRONT PRETENSIONER SQUIB LH CIRCUIT)

    A001CV5E03

    1. Disconnect the connectors from the center airbag sensor assembly.

    2. Connect the negative (-) terminal cable to the battery, and wait for at least 2 seconds.

    3. Turn the engine switch on (IG).

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

      Standard voltage
      Tester Connection Switch Condition Specified Condition
      S3-1 (L+) - Body ground Engine switch on (IG) Below 1 V
      S3-2 (L-) - Body ground Engine switch on (IG) Below 1 V

    5. Turn the engine switch off.

    6. Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.

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

      Standard resistance
      Tester Connection Condition Specified Condition
      S3-1 (L+) - S3-2 (L-) Always Below 1 Ω

    8. Release the activation prevention mechanism built into connector B Click here.

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

      Standard resistance
      Tester Connection Condition Specified Condition
      S3-1 (L+) - S3-2 (L-) Always 1 MΩ or higher
      S3-1 (L+) - Body ground Always 1 MΩ or higher
      S3-2 (L-) - Body ground Always 1 MΩ or higher

    NG

    REPLACE NO. 2 FLOOR WIRE

    OK

  4. CHECK CENTER AIRBAG SENSOR ASSEMBLY

    A001AFDE32
    *1 Front Pretensioner Squib LH
    *2 Center Airbag Sensor Assembly

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

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

    5. Turn the engine switch off.

    6. Turn the engine switch on (IG), and wait for at least 60 seconds.

    7. Check for DTCs Click here.

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

      Tech Tips

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


    OK

    USE SIMULATION METHOD TO CHECK Click here

    NG

    REPLACE CENTER AIRBAG SENSOR ASSEMBLY Click here