AIRBAG SYSTEM, Diagnostic DTC:B1820, B1821, B1822, B1823

DTC Code DTC Name
B1820 Short in Side Squib (RH) Circuit
B1821 Open in Side Squib (RH) Circuit
B1822 Short in Side Squib (RH) Circuit (to Ground)
B1823 Short in Side Squib (RH) Circuit (to +B)

DESCRIPTION

The front side squib RH circuit consists of the airbag ECU assembly and front seat airbag assembly RH.

The airbag ECU assembly uses this circuit to deploy the airbag when deployment conditions are met.

These DTCs are stored when a malfunction is detected in the front side squib RH circuit.

DTC No. DTC Detection Condition Trouble Area
B1820

  • The airbag ECU assembly receives a line short circuit signal in the front side squib RH circuit during primary check.

  • Front side squib RH malfunction

  • Airbag ECU assembly malfunction

  • No. 2 floor wire

  • Front seat assembly RH (Front seat wire RH)

  • Front seat airbag assembly RH (Front side squib RH)

  • Airbag ECU assembly
B1821

  • The airbag ECU assembly receives an open circuit signal in the front side squib RH circuit.

  • Front side squib RH malfunction

  • Airbag ECU assembly malfunction
B1822

  • The airbag ECU assembly receives a short circuit to ground signal in the front side squib RH circuit.

  • Front side squib RH malfunction

  • Airbag ECU assembly malfunction
B1823

  • The airbag ECU assembly receives a short circuit to B+ signal in the front side squib RH circuit.

  • Front side squib RH malfunction

  • Airbag ECU assembly malfunction

WIRING DIAGRAM

A004K0ZE01
*a Gc1
*b Front Seat Airbag Assembly RH (Front Side Squib RH)
*c Airbag ECU Assembly

CAUTION / NOTICE / HINT

Note

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

Tech Tips


  • 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.

PROCEDURE


  1. CHECK CONNECTORS


    1. A004KM1E01
      Text in Illustration
      *1 Front Seat Airbag Assembly RH
      *2 Airbag ECU Assembly
      *3 Front Seat Wire RH
      *4 No. 2 Floor Wire

      Turn the ignition switch off.

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

      CAUTION:

      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 airbag assembly RH and airbag ECU assembly. Also check that the connectors that link the No. 2 floor wire and front seat wire RH are properly connected.

      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 airbag assembly RH and airbag ECU assembly. Also disconnect the No. 2 floor wire from the front seat wire RH.

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

      OK
      The terminals are not deformed or damaged.

    6. Check that the front seat wire RH connector (on the front seat airbag assembly RH side) is not damaged.

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

    7. Check that the short springs for the No. 2 floor wire and the front seat wire RH with the activation prevention mechanism is not deformed or damaged.

      OK
      The short springs are not deformed or damaged.

    NG

    REPLACE WIRE HARNESS

    OK

  2. CHECK FRONT SEAT AIRBAG ASSEMBLY RH (FRONT SIDE SQUIB RH)


    1. A004JGFE02
      Text in Illustration
      *1 Front Seat Airbag Assembly RH
      *2 Airbag ECU Assembly
      *a

      Front view of wire harness connector

      (to Front Seat Airbag Assembly RH)

      Connect the No. 2 floor wire to the front seat wire RH and airbag ECU assembly.

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

      CAUTION:

      Never connect the tester to the front seat airbag assembly RH (front side 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 it.

      • Insert SST straight into the terminals of the connector.

      SST
      09843-18061

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

    4. Clear the DTCs stored in 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 B1820, B1821, B1822 or B1823 is not output.

      Tech Tips

      Codes other than DTCs B1820, B1821, B1822 and B1823 may be output at this time, but they are not related to this check.

    8. Turn the ignition switch off.

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

      CAUTION:

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

    10. Disconnect SST from connector E.


    OK

    REPLACE FRONT SEAT AIRBAG ASSEMBLY RH Click here

    NG

  3. CHECK FRONT SIDE SQUIB RH CIRCUIT


    1. A004KS3E03
      Text in Illustration
      *1 Front Seat Airbag Assembly RH
      *2 Airbag ECU Assembly
      *a

      Front view of wire harness connector

      (to Front Seat Airbag Assembly RH)

      Disconnect the No. 2 floor wire from the airbag ECU assembly.

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


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

      2. Turn the ignition switch to ON.

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

        Standard Voltage
        Tester Connection Condition Specified Condition
        c1-1 (SFR-) - Body ground Ignition switch ON Below 1 V
        c1-2 (SFR+) - Body ground Ignition switch ON Below 1 V

      4. Turn the ignition switch off.

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

        CAUTION:

        Wait at least 90 seconds after disconnecting the cable from the negative (-) 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
        c1-1 (SFR-) - c1-2 (SFR+) 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
        c1-1 (SFR-) - Body ground Always 1 MΩ or higher
        c1-2 (SFR+) - 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
        c1-1 (SFR-) - c1-2 (SFR+) Always 1 MΩ or higher

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


    NG

    CHECK NO. 2 FLOOR WIRE Click here

    OK

  4. CHECK DTC


    1. A004J71E01
      Text in Illustration
      *1 Front Seat Airbag Assembly RH
      *2 Airbag ECU Assembly

      Connect the connectors to the front seat airbag assembly RH and airbag ECU assembly.

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

    3. Clear the DTCs stored in memory Click here.

    4. Turn the ignition switch off.

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

    6. Check for DTCs Click here.

      OK
      DTC B1820, B1821, B1822 or B1823 is not output.

      Tech Tips

      Codes other than DTCs B1820, B1821, B1822 and B1823 may be output at this time, but they are not related to this check.


    OK

    USE SIMULATION METHOD TO CHECK Click here

    NG

    REPLACE AIRBAG ECU ASSEMBLY Click here

  5. CHECK NO. 2 FLOOR WIRE


    1. A004I4QE02
      Text in Illustration
      *1 Front Seat Airbag Assembly RH
      *2 Airbag ECU Assembly
      *3 Front Seat Wire RH
      *4 No. 2 Floor Wire
      *a

      Front view of wire harness connector

      (to Front Seat Wire RH)

      Disconnect the front seat wire RH from the No. 2 floor wire.

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


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

      2. Turn the ignition switch to ON.

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

        Standard Voltage
        Tester Connection Condition Specified Condition
        Gc1-1 - Body ground Ignition switch ON Below 1 V
        Gc1-2 - Body ground Ignition switch ON Below 1 V

      4. Turn the ignition switch off.

      5. 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 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
        Gc1-1 - Gc1-2 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
        Gc1-1 - Body ground Always 1 MΩ or higher
        Gc1-2 - 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
        Gc1-1 - Gc1-2 Always 1 MΩ or higher

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


    NG

    REPLACE NO. 2 FLOOR WIRE

    OK

  6. CHECK FRONT SEAT WIRE RH


    1. A004IWME02
      Text in Illustration
      *1 Front Seat Airbag Assembly RH
      *2 Airbag ECU Assembly
      *3 Front Seat Wire RH
      *4 No. 2 Floor Wire
      *a

      Front view of wire harness connector

      (to Front Seat Airbag Assembly RH)

      Check for a short to B+ in the circuit.


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

      2. Turn the ignition switch to ON.

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

        Standard Voltage
        Tester Connection Condition Specified Condition
        c1-1 (SFR-) - Body ground Ignition switch ON Below 1 V
        c1-2 (SFR+) - Body ground Ignition switch ON Below 1 V

      4. Turn the ignition switch off.

      5. 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.

    2. 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
        c1-1 (SFR-) - c1-2 (SFR+) Always Below 1 Ω

    3. 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
        c1-1 (SFR-) - Body ground Always 1 MΩ or higher
        c1-2 (SFR+) - Body ground Always 1 MΩ or higher

    4. Check for a short in the circuit.


      1. Release the activation prevention mechanism built into connector D Click here.

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

        Standard Resistance
        Tester Connection Condition Specified Condition
        c1-1 (SFR-) - c1-2 (SFR+) Always 1 MΩ or higher

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


    OK

    USE SIMULATION METHOD TO CHECK Click here

    NG

    REPLACE FRONT SEAT ASSEMBLY RH