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 front seat outer belt assembly 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 No. DTC Detection Condition Trouble Area
B1905/74
  • The center airbag sensor assembly receives a line short circuit signal 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
  • The center airbag sensor assembly receives an open circuit signal in the front pretensioner squib LH circuit.

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

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

  • 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

A019MVLE13

INSPECTION PROCEDURE

Tech Tips


  • Perform the simulation method by selecting Check Mode (Signal Check) using 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 a city or rough road Click here.

PROCEDURE


  1. CHECK CONNECTORS


    1. A019NFWE01
      Text in Illustration
      *1 Front Pretensioner Squib LH
      *2 Center Airbag Sensor Assembly
      *3 No. 2 Floor Wire

      Turn the engine switch off.

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

      Note

      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 center airbag sensor assembly.

      OK
      The connectors are properly connected.

      Tech Tips

      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 center 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 No. 2 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 No. 2 floor wire with the activation prevention mechanism is not deformed or damaged.

      OK
      The short spring is not deformed or damaged.

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


    1. A019JT9E01
      Text in Illustration
      *1 Front Pretensioner Squib LH
      *2 Center Airbag Sensor Assembly
      *3

      Front view of wire harness connector

      (to Front Seat Outer Belt Assembly LH)

      *4 Connector C

      Connect the connector to the center airbag sensor assembly.

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

      CAUTION:

      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 airbag 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 (-) battery terminal.

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

    5. Clear the DTCs stored in the memory Click here.

    6. Turn the engine switch off.

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

    8. 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.


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


    1. A019PGBE01
      Text in Illustration
      *1 Front Pretensioner Squib LH
      *2 Center Airbag Sensor Assembly
      *3 No. 2 Floor Wire
      *4

      Front view of wire harness connector

      (to Front Seat Outer Belt Assembly LH)

      *5 Connector C

      Turn the engine switch off.

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

      Note

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

    3. Disconnect SST from connector C.

    4. Disconnect the No. 2 floor wire from the center airbag sensor assembly.

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


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

      2. Turn the engine switch on (IG).

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

        Standard Voltage
        Tester Connection Switch Condition Specified Condition
        P5-1 (L+) - Body ground Engine switch on (IG) Below 1 V
        P5-2 (L-) - Body ground Engine switch on (IG) Below 1 V
    6. Check for an open in the circuit.


      1. Turn the engine switch off.

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

        Note

        Wait at least 90 seconds after disconnecting the cable from the negative (-) 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
        P5-1 (L+) - P5-2 (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
        P5-1 (L+) - Body ground Always 1 MΩ or higher
        P5-2 (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 Click here.

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

        Standard Resistance
        Tester Connection Condition Specified Condition
        P5-1 (L+) - P5-2 (L-) Always 1 MΩ or higher

    NG
    OK
  4. CHECK CENTER AIRBAG SENSOR ASSEMBLY


    1. A019PE6E01
      Text in Illustration
      *1 Front Pretensioner Squib LH
      *2 Center Airbag Sensor Assembly

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

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

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

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

    5. Clear the DTCs stored in the memory Click here.

    6. Turn the engine switch off.

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

    8. 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.


    NG
    OK