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

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DTC Code DTC Name
B1920 Short in Rear P/T Squib RH Circuit
B1921 Open in Rear P/T Squib RH Circuit
B1922 Short in Rear P/T Squib RH Circuit (To Ground)
B1923 Short in Rear P/T Squib RH Circuit (To B+)
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DESCRIPTION

The rear seat belt pretensioner RH circuit consists of the airbag ECU assembly and rear seat outer belt assembly RH.

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

These DTCs are stored when a malfunction is detected in the rear seat belt pretensioner RH circuit.

DTC No. Detection Item DTC Detection Condition Trouble Area Warning Indicate Test Mode / Check Mode
B1920 Short in Rear P/T Squib RH Circuit

One of the following conditions is met:


  • The airbag ECU assembly detects a line short circuit signal 5 times in the rear seat belt pretensioner RH circuit during the primary check.

  • A rear seat outer belt assembly RH malfunction.

  • An airbag ECU assembly malfunction.

  • Floor wire

  • Rear seat outer belt assembly RH

  • Airbag ECU assembly

 Comes on Applicable
B1921 Open in Rear P/T Squib RH Circuit

One of the following conditions is met:


  • The airbag ECU assembly detects an open circuit signal in the rear seat belt pretensioner RH circuit for 2 seconds.

  • A rear seat outer belt assembly RH malfunction.

  • An airbag ECU assembly malfunction.

  • Floor wire

  • Rear seat outer belt assembly RH

  • Airbag ECU assembly

 Comes on Applicable
B1922 Short in Rear P/T Squib RH Circuit (To Ground)

One of the following conditions is met:


  • The airbag ECU assembly detects a short circuit to ground signal in the rear seat belt pretensioner RH circuit for 0.5 seconds.

  • A rear seat outer belt assembly RH malfunction.

  • An airbag ECU assembly malfunction.

  • Floor wire

  • Rear seat outer belt assembly RH

  • Airbag ECU assembly

 Comes on Applicable
B1923 Short in Rear P/T Squib RH Circuit (To B+)

One of the following conditions is met:


  • The airbag ECU assembly detects a short circuit to B+ signal in the rear seat belt pretensioner RH circuit for 0.5 seconds.

  • A rear seat outer belt assembly RH malfunction.

  • An airbag ECU assembly malfunction.

  • Floor wire

  • Rear seat outer belt assembly RH

  • Airbag ECU assembly

 Comes on Applicable
Table 1. *a Rear Seat Outer Belt Assembly RH *b Airbag ECU 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.

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

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Tip:

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

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PROCEDURE


  1. Click here

    CHECK CONNECTORS


    1. B004YQ9C38
      *1 Rear Seat Outer Belt Assembly RH
      *2 Airbag ECU Assembly
      *3 Floor Wire

      Turn the power switch off.

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

    3. Check that the connectors are properly connected to the rear seat outer belt assembly RH and airbag ECU assembly.

      OK
      The connectors are properly connected.
      Tip:

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

    4. Disconnect the connectors from the rear seat outer belt assembly RH and airbag ECU assembly.

    5. Check that the terminals of the connectors are not deformed or damaged.

      OK
      The terminals are not deformed or damaged.

    6. Check that the floor wire connector (on the rear seat outer belt assembly RH side) is not loose, deformed or damaged.

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

    7. Check that the short springs of the activation prevention mechanism of the floor wire connector are not deformed or damaged.

      OK
      The short springs are not deformed or damaged.
      Result
      Proceed to
      OK
      NG

  2. Click here

    CHECK REAR SEAT OUTER BELT ASSEMBLY RH


    1. B004WWDC48
      *1 Rear Seat Outer Belt Assembly RH
      *2 Airbag ECU Assembly
      *3 SST
      *a

      Front view of wire harness connector

      (to Rear Seat Outer Belt Assembly RH)

      Connect the connector to the airbag ECU assembly.

    2. 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 assembly 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.

      09843-18061

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

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

    5. Clear the DTCs.

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      1. Body Electrical > SRS Airbag > Clear DTCs


    6. Turn the power switch off.

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

    8. Check for DTCs.

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      1. Body Electrical > SRS Airbag > Trouble Codes


      Result
      Proceed to
      DTC B1920, B1921, B1922 and B1923 are not output
      DTC B1920, B1921, B1922 or B1923 is output
      Tip:

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

    9. Turn the power switch off.

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

    11. Disconnect SST from connector C.


    • DTC B1920, B1921, B1922 and B1923 are not output

      REPLACE REAR SEAT OUTER BELT ASSEMBLY RH for Fixed Seat Type:

      REPLACE REAR SEAT OUTER BELT ASSEMBLY RHClick here

      REPLACE REAR SEAT OUTER BELT ASSEMBLY RH for Power Seat:

      REPLACE REAR SEAT OUTER BELT ASSEMBLY RHClick here

    • DTC B1920, B1921, B1922 or B1923 is outputClick here
  3. Click here

    CHECK FLOOR WIRE


    1. B004VF8C05
      *1 Rear Seat Outer Belt Assembly RH
      *2 Airbag ECU Assembly
      *3 Floor Wire
      *a

      Front view of wire harness connector

      (to Rear Seat Outer Belt Assembly RH)
      B004SZX Release the activation prevention mechanism

      Disconnect the floor wire from the airbag ECU 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 Switch Condition Specified Condition
        L43-1 (RR+) - Body ground Power switch on (IG) Below 1 V
        L43-2 (RR-) - 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, and wait for at least 90 seconds.

    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
        L43-1 (RR+) - L43-2 (RR-) 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
        L43-1 (RR+) - Body ground Always 1 MΩ or higher
        L43-2 (RR-) - 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
        L43-1 (RR+) - L43-2 (RR-) Always 1 MΩ or higher

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

      Result
      Proceed to
      OK
      NG

  4. Click here

    CHECK DTC


    1. B004UFOC26
      *1 Rear Seat Outer Belt Assembly RH
      *2 Airbag ECU Assembly

      Connect the connectors to the rear seat outer belt assembly RH and airbag ECU assembly.

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

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

    4. Clear the DTCs stored in memory.

      Click here


      1. Body Electrical > SRS Airbag > Clear DTCs


    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


      1. Body Electrical > SRS Airbag > Trouble Codes


      Result
      Proceed to
      DTC B1920, B1921, B1922 and B1923 are not output
      DTC B1920, B1921, B1922 or B1923 is output
      Tip:

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


    • DTC B1920, B1921, B1922 and B1923 are not output

      USE SIMULATION METHOD TO CHECKClick here

    • DTC B1920, B1921, B1922 or B1923 is output

      REPLACE AIRBAG ECU ASSEMBLYClick here