AIRBAG SYSTEM, Diagnostic DTC:B1875/67, B1876/67, B1877/67, B1878/67

DTC Code DTC Name
B1875/67 Short in Passenger Side Front Seat Cushion Squib Circuit
B1876/67 Open in Passenger Side Front Seat Cushion Squib Circuit
B1877/67 Short to GND in Passenger Side Front Seat Cushion Squib Circuit
B1878/67 Short to B+ in Passenger Side Front Seat Cushion Squib Circuit

DESCRIPTION

The front seat cushion squib LH/RH circuit consists of the airbag ECU assembly and the front seat cushion airbag assembly LH/RH.

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

These DTCs are recorded when a malfunction is detected in the front seat cushion squib LH/RH circuit.

DTC No. Detection Item DTC Detection Condition Trouble Area
B1875/67 Short in Passenger Side Front Seat Cushion Squib Circuit

    One of the following conditions is met:

  • The airbag ECU assembly receives a line short circuit signal 5 times in the front seat cushion squib LH/RH circuit during primary check.

  • A front seat cushion airbag assembly LH/RH malfunction

  • An airbag ECU assembly malfunction

  • Front seat cushion airbag assembly LH (for RHD)

  • No. 2 Floor wire (for RHD)

  • Floor wire (for LHD)

  • Front seat cushion airbag assembly RH (for LHD)

  • Airbag ECU assembly
B1876/67 Open in Passenger Side Front Seat Cushion Squib Circuit

    One of the following conditions is met:

  • The airbag ECU assembly receives an open circuit signal in the front seat cushion squib LH/RH circuit for 2 seconds.

  • A front seat cushion airbag assembly LH/RH malfunction

  • An airbag ECU assembly malfunction

  • Front seat cushion airbag assembly LH (for RHD)

  • No. 2 Floor wire (for RHD)

  • Floor wire (for LHD)

  • Front seat cushion airbag assembly RH (for LHD)

  • Airbag ECU assembly
B1877/67 Short to GND in Passenger Side Front Seat Cushion Squib Circuit

    One of the following conditions is met:

  • The airbag ECU assembly receives a short circuit to ground signal in the front seat cushion squib LH/RH circuit for 0.5 seconds.

  • A front seat cushion airbag assembly LH/RH malfunction

  • An airbag ECU assembly malfunction

  • Front seat cushion airbag assembly LH (for RHD)

  • No. 2 Floor wire (for RHD)

  • Floor wire (for LHD)

  • Front seat cushion airbag assembly RH (for LHD)

  • Airbag ECU assembly
B1878/67 Short to B+ in Passenger Side Front Seat Cushion Squib Circuit

    One of the following conditions is met:

  • The airbag ECU assembly receives a short circuit to B+ signal in the front seat cushion squib LH/RH circuit for 0.5 seconds.

  • A front seat cushion airbag assembly LH/RH malfunction

  • An airbag ECU assembly malfunction

  • Front seat cushion airbag assembly LH (for RHD)

  • No. 2 Floor wire (for RHD)

  • Floor wire (for LHD)

  • Front seat cushion airbag assembly RH (for LHD)

  • Airbag ECU assembly

WIRING DIAGRAM

B00599AE96

CAUTION / NOTICE / HINT

Note


  • After turning the engine 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

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

    Click here

  • After replacing the airbag ECU assembly, refer to initialization.

    Click here

Tech Tips

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.

PROCEDURE


  1. CHECK VEHICLE CONDITION


    1. Check vehicle condition.

      Result
      Proceed to
      for LHD
      for RHD

    for RHD

    CHECK FRONT SEAT CUSHION AIRBAG ASSEMBLY LH Click here

    for LHD

  2. CHECK FRONT SEAT CUSHION AIRBAG ASSEMBLY RH


    1. B00590JC02
      *1 Front Seat Cushion Airbag Assembly RH
      *2 Airbag ECU Assembly
      *3 Connector C
      *4 SST
      *a

      Front view of wire harness connector

      (to Front Seat Cushion Airbag Assembly RH)

      Turn the engine switch off.

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

    3. Disconnect the connector from the front seat cushion airbag assembly RH.

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

      CAUTION:

      Never connect the tester to the front seat cushion airbag 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.

      SST
      09843-18061

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

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

    7. Clear the DTCs.

      Click here


      Body Electrical > SRS Airbag > Clear DTCs

    8. Turn the engine switch off.

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

    10. Check for DTCs.

      Click here


      Body Electrical > SRS Airbag > Trouble Codes
      Result
      Proceed to
      DTC B1875/67, B1876/67, B1877/67 or B1878/67 is not output.
      DTC B1875/67, B1876/67, B1877/67 or B1878/67 is output.

      Tech Tips

      Codes other than DTC B1875/67, B1876/67, B1877/67 or B1878/67 may be output at this time, but they are not related to this check.

    11. Turn the engine switch off.

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

    13. Disconnect SST from connector C.


    DTC B1875/67, B1876/67, B1877/67 or B1878/67 is not output.

    REPLACE FRONT SEAT CUSHION AIRBAG ASSEMBLY RH for Power Seat: Click here
    REPLACE FRONT SEAT CUSHION AIRBAG ASSEMBLY RH for Manual Seat: Click here

    DTC B1875/67, B1876/67, B1877/67 or B1878/67 is output.

  3. CHECK CONNECTORS


    1. Disconnect the connectors from the airbag ECU assembly.

    2. B0059HAC02
      *1 Front Seat Cushion Airbag Assembly RH
      *2 Floor Wire
      *3 Airbag ECU Assembly

      Check that the connectors (on the airbag ECU assembly side and front seat cushion airbag assembly RH side) are not damaged.

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

    NG

    REPLACE FLOOR WIRE

    OK

  4. CHECK FLOOR WIRE


    1. B005AU2C01
      *1 Front Seat Cushion Airbag Assembly RH
      *2 Airbag ECU Assembly
      *3 Floor Wire
      *4 Connector C
      *a

      Front view of wire harness connector

      (to Front Seat Cushion Airbag Assembly RH)

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

    2. Turn the engine switch on (IG).

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      Pq1-1 (FCP-) - Body ground Engine switch on (IG) Below 1 V
      Pq1-2 (FCP+) - Body ground Engine switch on (IG) Below 1 V

    4. Turn the engine 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
      Pq1-1 (FCP-) - Pq1-2 (FCP+) 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
      Pq1-1 (FCP-) - Pq1-2 (FCP+) Always 1 MΩ or higher

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

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      Pq1-1 (FCP-) - Body ground Always 1 MΩ or higher
      Pq1-2 (FCP+) - Body ground Always 1 MΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE FLOOR WIRE

    OK

  5. CHECK DTC


    1. B005AAIC10
      *1 Front Seat Cushion Airbag Assembly RH
      *2 Airbag ECU Assembly

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

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

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

    4. Clear the DTCs.

      Click here


      Body Electrical > SRS Airbag > Clear DTCs

    5. Turn the engine switch off.

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

    7. Check for DTCs.

      Click here


      Body Electrical > SRS Airbag > Trouble Codes
      Result
      Proceed to
      DTC B1875/67, B1876/67, B1877/67 or B1878/67 is not output.
      DTC B1875/67, B1876/67, B1877/67 or B1878/67 is output.

      Tech Tips

      Codes other than DTC B1875/67, B1876/67, B1877/67 or B1878/67 may be output at this time, but they are not related to this check.


    DTC B1875/67, B1876/67, B1877/67 or B1878/67 is not output.

    USE SIMULATION METHOD TO CHECK Click here

    DTC B1875/67, B1876/67, B1877/67 or B1878/67 is output.

    REPLACE AIRBAG ECU ASSEMBLY Click here

  6. CHECK FRONT SEAT CUSHION AIRBAG ASSEMBLY LH


    1. B005A38C01
      *1 Front Seat Cushion Airbag Assembly LH
      *2 Airbag ECU Assembly
      *3 Connector C
      *4 SST
      *a

      Front view of wire harness connector

      (to Front Seat Cushion Airbag Assembly LH)

      Turn the engine switch off.

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

    3. Disconnect the connector from the front seat cushion airbag assembly LH.

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

      CAUTION:

      Never connect the tester to the front seat cushion airbag assembly 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.

      SST
      09843-18061

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

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

    7. Clear the DTCs.

      Click here


      Body Electrical > SRS Airbag > Clear DTCs

    8. Turn the engine switch off.

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

    10. Check for DTCs.

      Click here


      Body Electrical > SRS Airbag > Trouble Codes
      Result
      Proceed to
      DTC B1875/67, B1876/67, B1877/67 or B1878/67 is not output.
      DTC B1875/67, B1876/67, B1877/67 or B1878/67 is output.

      Tech Tips

      Codes other than DTC B1875/67, B1876/67, B1877/67 or B1878/67 may be output at this time, but they are not related to this check.

    11. Turn the engine switch off.

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

    13. Disconnect SST from connector C


    DTC B1875/67, B1876/67, B1877/67 or B1878/67 is not output.

    REPLACE FRONT SEAT CUSHION AIRBAG ASSEMBLY LH for Manual Seat: Click here
    REPLACE FRONT SEAT CUSHION AIRBAG ASSEMBLY LH for Power Seat: Click here

    DTC B1875/67, B1876/67, B1877/67 or B1878/67 is output.

  7. CHECK CONNECTORS


    1. Disconnect the connectors from the airbag ECU assembly.

    2. B0059PTC05
      *1 Front Seat Cushion Airbag Assembly LH
      *2 No. 2 Floor Wire
      *3 Airbag ECU Assembly

      Check that the connectors (on the airbag ECU assembly side and front seat cushion airbag assembly LH side) are not damaged.

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

    NG

    REPLACE NO. 2 FLOOR WIRE

    OK

  8. CHECK NO. 2 FLOOR WIRE


    1. B005966C02
      *1 Front Seat Cushion Airbag Assembly LH
      *2 Airbag ECU Assembly
      *3 No. 2 Floor Wire
      *4 Connector C
      *a

      Front view of wire harness connector

      (to Front Seat Cushion Airbag Assembly LH)

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

    2. Turn the engine switch on (IG).

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      Qu1-1 (FCP-) - Body ground Engine switch on (IG) Below 1 V
      Qu1-2 (FCP+) - Body ground Engine switch on (IG) Below 1 V

    4. Turn the engine 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
      Qu1-1 (FCP-) - Qu1-2 (FCP+) 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
      Qu1-1 (FCP-) - Qu1-2 (FCP+) Always 1 MΩ or higher

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

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      Qu1-1 (FCP-) - Body ground Always 1 MΩ or higher
      Qu1-2 (FCP+) - Body ground Always 1 MΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE NO. 2 FLOOR WIRE

    OK

  9. CHECK DTC


    1. B0059JZC22
      *1 Front Seat Cushion Airbag Assembly LH
      *2 Airbag ECU Assembly

      Connect the connectors to the front seat cushion airbag assembly LH and the airbag ECU assembly.

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

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

    4. Clear the DTCs.

      Click here


      Body Electrical > SRS Airbag > Clear DTCs

    5. Turn the engine switch off.

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

    7. Check for DTCs.

      Click here


      Body Electrical > SRS Airbag > Trouble Codes
      Result
      Proceed to
      DTC B1875/67, B1876/67, B1877/67 or B1878/67 is not output.
      DTC B1875/67, B1876/67, B1877/67 or B1878/67 is output.

      Tech Tips

      Codes other than DTC B1875/67, B1876/67, B1877/67 or B1878/67 may be output at this time, but they are not related to this check.


    DTC B1875/67, B1876/67, B1877/67 or B1878/67 is not output.

    USE SIMULATION METHOD TO CHECK Click here

    DTC B1875/67, B1876/67, B1877/67 or B1878/67 is output.

    REPLACE AIRBAG ECU ASSEMBLY Click here