AIRBAG SYSTEM, Diagnostic DTC:B1920/77, B1921/77, B1922/77, B1923/77

DTC Code DTC Name
B1920/77 Short in Rear Pretensioner Squib RH Circuit
B1921/77 Open in Rear Pretensioner Squib RH Circuit
B1922/77 Short to GND in Rear Pretensioner Squib RH Circuit
B1923/77 Short to B+ in Rear Pretensioner Squib RH Circuit

DESCRIPTION

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

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

Theses DTCs are stored when a malfunction is detected in the rear pretensioner squib RH circuit.

DTC Code DTC Detection Condition Trouble Area
B1920/77

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 RH circuit during the primary check.

  • A rear pretensioner squib RH malfunction.

  • A center airbag sensor malfunction.

  • No. 2 floor wire

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

  • Center airbag sensor assembly
B1921/77

When one of the following conditions is met:


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

  • A rear pretensioner squib RH malfunction.

  • A center airbag sensor malfunction.

  • No. 2 floor wire

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

  • Center airbag sensor assembly
B1922/77

When one of the following conditions is met:


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

  • A rear pretensioner squib RH malfunction.

  • A center airbag sensor malfunction.

  • No. 2 floor wire

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

  • Center airbag sensor assembly
B1923/77

When one of the following conditions is met:


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

  • A rear pretensioner squib RH malfunction.

  • A center airbag sensor malfunction.

  • No. 2 floor wire

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

  • Center airbag sensor assembly

WIRING DIAGRAM

B001WN3E11
*a Rear Pretensioner Squib LH
*b Center Airbag Sensor

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.

Tech Tips

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.

PROCEDURE


  1. CHECK REAR SEAT OUTER BELT RH (REAR PRETENSIONER SQUIB RH)


    1. B001WS2E01
      *1 Center Airbag Sensor
      *2 Rear Pretensioner Squib RH
      *3 Front view of wire harness connector: (to Rear Pretensioner Squib RH)
      *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 RH.

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

      CAUTION:

      Never connect the tester to the rear seat outer belt RH (rear pretensioner squib RH) 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 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 stored in the memory 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 B1920, B1921, B1922 or B1923 is not output.

      Tech Tips

      Codes other than DTC B1920, B1921, B1922 and B1923 may be output at this time, but they are not related to this check.


    OK

    REPLACE REAR SEAT OUTER BELT ASSEMBLY RH Click here

    NG

  2. CHECK CONNECTORS


    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 No. 2 floor wire connector (on the rear seat outer belt RH side) is not damaged.

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

    NG

    REPLACE NO. 2 FLOOR WIRE

    OK

  3. CHECK NO. 2 FLOOR WIRE (REAR PRETENSIONER SQUIB RH CIRCUIT)


    1. B001YNLE02

      Disconnect the connectors from the center airbag sensor.

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

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      L14-1 (RR+) - Body ground Ignition switch ON Below 1 V
      L14-2 (RR-) - 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
      L14-1 (RR+) - L14-2 (RR-) 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
      L14-1 (RR+) - L14-2 (RR-) Always 1 MΩ or higher
      L14-1 (RR+) - Body ground Always 1 MΩ or higher
      L14-2 (RR-) - Body ground Always 1 MΩ or higher

    NG

    REPLACE NO. 2 FLOOR WIRE

    OK

  4. CHECK CENTER AIRBAG SENSOR


    1. B001WELE76
      *1 Center Airbag Sensor
      *2 Rear Pretensioner Squib RH

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

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

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

    4. Clear the DTCs stored in the memory 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 B1920, B1921, B1922 or B1923 is not output.

      Tech Tips

      Codes other than DTC B1920, B1921, B1922 and B1923 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