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AIRBAG SYSTEM, Diagnostic DTC:B1925/78, B1926/78, B1927/78, B1928/78

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DTC Code DTC Name
B1925/78 Short in Rear Pretensioner Squib LH Circuit
B1926/78 Open in Rear Pretensioner Squib LH Circuit
B1927/78 Short to GND in Rear Pretensioner Squib LH Circuit
B1928/78 Short to B+ in Rear Pretensioner Squib LH Circuit
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DESCRIPTION

The rear pretensioner squib LH circuit consists of the airbag sensor assembly and rear seat 3 point type 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 rear pretensioner squib LH circuit.

DTC No. DTC Detection Condition Trouble Area
B1925/78

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

  • Rear pretensioner squib LH malfunction

  • Airbag sensor assembly malfunction

  • Floor wire

  • Rear seat 3 point type outer belt assembly LH (Rear pretensioner squib LH)

  • Airbag sensor assembly
B1926/78

  • The airbag sensor assembly receives an open circuit signal in the rear pretensioner squib LH circuit.

  • Rear pretensioner squib LH malfunction

  • Airbag sensor assembly malfunction
B1927/78

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

  • Rear pretensioner squib LH malfunction

  • Airbag sensor assembly malfunction
B1928/78

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

  • Rear pretensioner squib LH malfunction

  • Airbag sensor assembly malfunction
Table 1. *a Rear Seat 3 Point Type Outer Belt Assembly LH (Rear Pretensioner Squib LH) *b Airbag Sensor Assembly
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WIRING DIAGRAM

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CAUTION / NOTICE / HINT

Note:

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

Tip:

  • Perform the simulation method by selecting check mode (Signal Check) using the GTS (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 road or rough road (Click here).

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PROCEDURE


  1. Click here

    CHECK CONNECTORS


    1. A00042UE05

      Turn the power switch off.

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

      CAUTION:

      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 rear seat 3 point type outer belt assembly LH and airbag sensor assembly.

      OK
      The connectors are properly connected.
      Tip:

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

    4. Disconnect the connectors from the rear seat 3 point type 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 rear seat 3 point type 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.
      Table 2. Text in Illustration
      *1 Rear Seat 3 Point Type Outer Belt Assembly LH
      *2 Airbag Sensor Assembly
      *3 Floor Wire

  2. Click here

    CHECK REAR SEAT 3 POINT TYPE OUTER BELT ASSEMBLY LH (REAR PRETENSIONER SQUIB LH)


    1. A000659E02

      Connect the connector to the airbag sensor assembly.

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

      CAUTION:

      Never connect the tester to the rear seat 3 point type outer belt assembly LH (rear 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.

      09843-18061

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

    4. Clear the DTCs stored in memory (Click here).

    5. Turn the power switch off.

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

    7. Check for DTCs (Click here).

      OK
      DTC B1925/78, B1926/78, B1927/78 or B1928/78 is not output.
      Tip:

      Codes other than DTCs B1925/78, B1926/78, B1927/78 and B1928/78 may be output at this time, but they are not related to this check.

    8. Turn the power switch off.

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

      CAUTION:

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

    10. Disconnect SST from connector C.

      Table 3. Text in Illustration
      *1 Rear Seat 3 Point Type Outer Belt Assembly LH
      *2 Airbag Sensor Assembly
      *a

      Front view of wire harness connector

      (to Rear Seat 3 Point Type Outer Belt Assembly LH)

  3. Click here

    CHECK FLOOR WIRE


    1. A00085EE02

      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 (-) 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 Condition Specified Condition
        P22-1 (RL+) - Body ground Power switch on (IG) Below 1 V
        P22-2 (RL-) - 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.

        CAUTION:

        Wait at least 90 seconds after disconnecting the cable from the negative (-) auxiliary 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
        P22-1 (RL+) - P22-2 (RL-) 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
        P22-1 (RL+) - Body ground Always 1 MΩ or higher
        P22-2 (RL-) - 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 here).

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

        Standard Resistance
        Tester Connection Condition Specified Condition
        P22-1 (RL+) - P22-2 (RL-) Always 1 MΩ or higher

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

        Table 4. Text in Illustration
        *1 Rear Seat 3 Point Type Outer Belt Assembly LH
        *2 Airbag Sensor Assembly
        *3 Floor Wire
        *a

        Front view of wire harness connector

        (to Rear Seat 3 Point Type Outer Belt Assembly LH)

  4. Click here

    CHECK DTC


    1. A0004AWE12

      Connect the connectors to the rear seat 3 point type outer belt assembly LH and airbag sensor assembly.

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

    3. Clear the DTCs stored in memory (Click here).

    4. Turn the power switch off.

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

    6. Check for DTCs (Click here).

      OK
      DTC B1925/78, B1926/78, B1927/78 or B1928/78 is not output.
      Tip:

      Codes other than DTCs B1925/78, B1926/78, B1927/78 and B1928/78 may be output at this time, but they are not related to this check.

      Table 5. Text in Illustration
      *1 Rear Seat 3 Point Type Outer Belt Assembly LH
      *2 Airbag Sensor Assembly