AIRBAG SYSTEM, Diagnostic DTC:B1940/75, B1941/75, B1942/75, B1943/75

DTC Code DTC Name
B1940/75 Short in Selectable Force Limiter Squib RH Circuit
B1941/75 Open in Selectable Force Limiter Squib RH Circuit
B1942/75 Short to GND in Selectable Force Limiter Squib RH Circuit
B1943/75 Short to +B in Selectable Force Limiter Squib RH Circuit

DESCRIPTION

The selectable force limiter circuit consists of the airbag ECU assembly and front 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 selectable force limiter circuit.

DTC No. Detection Item DTC Detection Condition Trouble Area
B1940/75 Short in Selectable Force Limiter Squib RH Circuit

    One of the following conditions is met:

  • The airbag ECU assembly detects a line short circuit signal 5 times in the selectable force limiter circuit during the primary check.

  • A selectable force limiter malfunction.

  • An airbag ECU assembly malfunction.

  • Floor wire

  • Front seat outer belt assembly RH (Selectable force limiter)

  • Airbag ECU assembly
B1941/75 Open in Selectable Force Limiter Squib RH Circuit

    One of the following conditions is met:

  • The airbag ECU assembly detects an open circuit signal in the selectable force limiter circuit for 2 seconds.

  • A selectable force limiter malfunction.

  • An airbag ECU assembly malfunction.

  • Floor wire

  • Front seat outer belt assembly RH (Selectable force limiter)

  • Airbag ECU assembly
B1942/75 Short to GND in Selectable Force Limiter Squib RH Circuit

    One of the following conditions is met:

  • The airbag ECU assembly detects a short circuit to ground signal in the selectable force limiter circuit for 0.5 seconds.

  • A selectable force limiter malfunction.

  • An airbag ECU assembly malfunction.

  • Floor wire

  • Front seat outer belt assembly RH (Selectable force limiter)

  • Airbag ECU assembly
B1943/75 Short to +B in Selectable Force Limiter Squib RH Circuit

    One of the following conditions is met:

  • The airbag ECU assembly detects a short circuit to B+ signal in the selectable force limiter circuit for 0.5 seconds.

  • A selectable force limiter malfunction.

  • An airbag ECU assembly malfunction.

  • Floor wire

  • Front seat outer belt assembly RH (Selectable force limiter)

  • Airbag ECU assembly

WIRING DIAGRAM

B008I0EE99
*a Front Seat Outer Belt Assembly RH (Selectable Force Limiter)
*b Airbag ECU Assembly

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 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 FRONT SEAT OUTER BELT ASSEMBLY RH (SELECTABLE FORCE LIMITER)


    1. B008IIIC12
      *1 Front Seat Outer Belt Assembly RH (Selectable Force Limiter)
      *2 Airbag ECU Assembly
      *3 Connector C
      *4 SST
      *a

      Front view of wire harness connector

      (to Front Seat Outer Belt Assembly RH [Selectable Force Limiter])

      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 outer belt assembly RH.

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

      CAUTION:

      Never connect the tester to the front seat outer belt assembly RH (selectable force limiter) 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 B1940/75, B1941/75, B1942/75 or B1943/75 is not output
      DTC B1940/75, B1941/75, B1942/75 or B1943/75 is output

      Tech Tips

      Codes other than DTC B1940/75, B1941/75, B1942/75 or B1943/75 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 B1940/75, B1941/75, B1942/75 or B1943/75 is not output

    REPLACE FRONT SEAT OUTER BELT ASSEMBLY RH Click here

    DTC B1940/75, B1941/75, B1942/75 or B1943/75 is output

  2. CHECK CONNECTORS


    1. Disconnect the connectors from the airbag ECU assembly.

    2. B008INSC02
      *1 Front Seat Outer Belt Assembly RH (Selectable Force Limiter)
      *2 Floor Wire
      *3 Airbag ECU Assembly

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

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

    NG

    REPLACE FLOOR WIRE

    OK

  3. CHECK SELECTABLE FORCE LIMITER CIRCUIT


    1. B008INRC12
      *1 Selectable Force Limiter
      *2 Floor Wire
      *3 Airbag ECU Assembly
      *4 Connector C
      *a

      Front view of wire harness connector

      (to Front Seat Outer Belt Assembly RH [Selectable Force Limiter])

      Connect the cable to the negative (-) battery terminal, 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
      P40-2 (SR+) - Body ground Engine switch on (IG) Below 1 V
      P40-1 (SR-) - 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
      P40-2 (SR+) - P40-1 (SR-) 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
      P40-2 (SR+) - P40-1 (SR-) 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
      P40-2 (SR+) - Body ground Always 1 MΩ or higher
      P40-1 (SR-) - Body ground Always 1 MΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE FLOOR WIRE

    OK

  4. CHECK AIRBAG ECU ASSEMBLY


    1. B008JBFC10
      *1 Front Seat Outer Belt Assembly RH (Selectable Force Limiter)
      *2 Airbag ECU Assembly

      Connect the connectors to the front seat outer belt assembly RH and 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 B1940/75, B1941/75, B1942/75 or B1943/75 is not output
      DTC B1940/75, B1941/75, B1942/75 or B1943/75 is output

      Tech Tips

      Codes other than B1940/75, B1941/75, B1942/75 or B1943/75 may be output at this time, but they are not related to this check.


    DTC B1940/75, B1941/75, B1942/75 or B1943/75 is not output

    USE SIMULATION METHOD TO CHECK Click here

    DTC B1940/75, B1941/75, B1942/75 or B1943/75 is output

    REPLACE AIRBAG ECU ASSEMBLY Click here