Click here

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

Click here
Click here Click here
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
Click here

DESCRIPTION

The rear pretensioner squib LH circuit consists of the center airbag sensor and the rear seat outer belt LH.

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

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

DTC Code DTC Detection Condition Trouble Area
B1925/78

When one of the following conditions is met:


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

  • A rear pretensioner squib LH malfunction.

  • A center airbag sensor malfunction.

  • Floor wire

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

  • Center airbag sensor assembly
B1926/78

When one of the following conditions is met:


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

  • A rear pretensioner squib LH malfunction.

  • A center airbag sensor malfunction.

  • Floor wire

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

  • Center airbag sensor assembly
B1927/78

When one of the following conditions is met:


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

  • A rear pretensioner squib LH malfunction.

  • A center airbag sensor malfunction.

  • Floor wire

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

  • Center airbag sensor assembly
B1928/78

When one of the following conditions is met:


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

  • A rear pretensioner squib LH malfunction.

  • A center airbag sensor malfunction.

  • Floor wire

  • Rear seat outer belt assembly LH (rear pretensioner squib LH)

  • Center airbag sensor assembly
Table 1. *a Rear Pretensioner Squib LH *b Center Airbag Sensor
Click here

WIRING DIAGRAM

Click here

CAUTION / NOTICE / HINT

Note:

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

  • When disconnecting the cable, some systems need to be initialized after the cable is reconnected (Click here).

  • After replacing the center airbag sensor assembly, refer to initialization (Click here).

Tip:

To perform the simulation method, enter the check mode (signal check) with the intelligent tester (See page ), and then wiggle each connector of the airbag system or drive the vehicle on various type of road (Click here).

Click here

PROCEDURE


  1. Click here

    CHECK REAR SEAT OUTER BELT LH (REAR PRETENSIONER SQUIB LH)


    1. B001WFSE03
      Table 2.
      *1 Center Airbag Sensor
      *2 Rear Pretensioner Squib LH
      *3 Front view of wire harness connector: (to Rear Pretensioner Squib LH)
      *4 Connector C

      Turn the ignition switch off.

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

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

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

      CAUTION:

      Never connect the tester to the rear seat outer belt LH (rear 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.

      09843-18061

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

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

    7. Clear the DTCs (Click here).

    8. Turn the ignition switch off.

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

    10. Check for DTCs (Click here).

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

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


  2. Click here

    CHECK CONNECTOR


    1. Turn the ignition switch off.

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

    3. Disconnect SST from connector C.

    4. Check that the floor wire connector (on the rear seat outer belt LH side) is not damaged.

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

  3. Click here

    CHECK FLOOR WIRE (REAR PRETENSIONER SQUIB LH CIRCUIT)


    1. B001YU5E02

      Disconnect the connectors from the center airbag sensor.

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

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      K13-1 (RL+) - Body ground Ignition switch ON Below 1 V
      K13-2 (RL-) - Body ground Ignition switch ON Below 1 V

    4. Turn the ignition switch off.

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

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      K13-1 (RL+) - K13-2 (RL-) Always Below 1 Ω

    7. Release the activation prevention mechanism built into connector B (Click here).

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      K13-1 (RL+) - K13-2 (RL-) Always 1 MΩ or higher
      K13-1 (RL+) - Body ground Always 1 MΩ or higher
      K13-2 (RL-) - Body ground Always 1 MΩ or higher

  4. Click here

    CHECK CENTER AIRBAG SENSOR


    1. B001ZW3E06
      Table 3.
      *1 Center Airbag Sensor
      *2 Rear Pretensioner Squib LH

      Connect the connectors to the rear seat outer belt LH and the center airbag sensor.

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

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

    4. Clear the DTCs (Click here).

    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).

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

      Codes other than DTC B1925, B1926, B1927 or B1928 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)