AIRBAG SYSTEM(for Type A), Diagnostic DTC:B1900/73, B1901/73, B1902/73, B1903/73

DTC Code DTC Name
B1900/73 Short in Front Pretensioner Squib RH Circuit
B1901/73 Open in Front Pretensioner Squib RH Circuit
B1902/73 Short to GND in Front Pretensioner Squib RH Circuit
B1903/73 Short to B+ in Front Pretensioner Squib RH Circuit

DESCRIPTION

The front pretensioner RH circuit consists of the airbag sensor 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 front pretensioner RH circuit.

DTC No. Detection Item DTC Detection Condition Trouble Area
B1900/73 Short in Front Pretensioner Squib RH Circuit

One of the following conditions is met:


  • The airbag sensor assembly detects a line short circuit signal 5 times in the front pretensioner RH circuit during the primary check.

  • A front seat outer belt assembly RH malfunction.

  • An airbag sensor assembly malfunction.

  • Floor wire

  • Front seat outer belt assembly RH

  • Airbag sensor assembly
B1901/73 Open in Front Pretensioner Squib RH Circuit

One of the following conditions is met:


  • The airbag sensor assembly detects an open circuit signal in the front pretensioner RH circuit for 2 seconds.

  • A front seat outer belt assembly RH malfunction.

  • An airbag sensor assembly malfunction.

  • Floor wire

  • Front seat outer belt assembly RH

  • Airbag sensor assembly
B1902/73 Short to GND in Front Pretensioner Squib RH Circuit

One of the following conditions is met:


  • The airbag sensor assembly detects a short circuit to ground signal in the front pretensioner RH circuit for 0.5 seconds.

  • A front seat outer belt assembly RH malfunction.

  • An airbag sensor assembly malfunction.

  • Floor wire

  • Front seat outer belt assembly RH

  • Airbag sensor assembly
B1903/73 Short to B+ in Front Pretensioner Squib RH Circuit

One of the following conditions is met:


  • The airbag sensor assembly detects a short circuit to B+ signal in the front pretensioner RH circuit for 0.5 seconds.

  • A front seat outer belt assembly RH malfunction.

  • An airbag sensor assembly malfunction.

  • Floor wire

  • Front seat outer belt assembly RH

  • Airbag sensor assembly

WIRING DIAGRAM

B003NK6E43
*a Front Seat Outer Belt Assembly RH
*b Airbag Sensor 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

  • 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

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


    1. B003JMFC05
      *1 Front Seat Outer Belt Assembly RH
      *2 Airbag Sensor Assembly
      *3 Connector C
      *4 SST
      *a

      Front view of wire harness connector

      (to Front Seat Outer Belt Assembly RH)

      Turn the ignition 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 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.

      Click here


      Body Electrical > SRS Airbag > Clear DTCs

    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


      Body Electrical > SRS Airbag > Trouble Codes
      Result
      Proceed to
      DTC B1905/74, B1906/74, B1907/74 or B1908/74 is not output
      DTC B1905/74, B1906/74, B1907/74 or B1908/74 is output

      Tech Tips

      Codes other than DTC B1905/74, B1906/74, B1907/74 and B1908/74 may be output at this time, but they are not related to this check.

    11. Turn the ignition 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 B1905/74, B1906/74, B1907/74 or B1908/74 is not output

    REPLACE FRONT SEAT OUTER BELT ASSEMBLY RH Click here

    DTC B1905/74, B1906/74, B1907/74 or B1908/74 is output

  2. CHECK CONNECTORS


    1. Disconnect the connector from the airbag sensor assembly.

    2. B003PIWC01
      *1 Front Seat Outer Belt Assembly RH
      *2 Floor Wire
      *3 Airbag Sensor Assembly

      Check that the connectors (on the airbag sensor 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 FLOOR WIRE


    1. B003RMSC08
      *1 Front Seat Outer Belt Assembly RH
      *2 Floor Wire
      *3 Airbag Sensor Assembly
      *4 Connector C
      *a

      Front view of wire harness connector

      (to Front Seat Outer Belt Assembly RH)

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

    2. Turn the ignition switch to ON.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      N18-1 (R-) - Body ground Ignition switch ON Below 1 V
      N18-2 (R+) - 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
      N18-1 (R-) - N18-2 (R+) 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
      N18-1 (R-) - N18-2 (R+) 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
      N18-1 (R-) - Body ground Always 1 MΩ or higher
      N18-2 (R+) - Body ground Always 1 MΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE FLOOR WIRE

    OK

  4. CHECK DTC


    1. B003L7RC03
      *1 Front Seat Outer Belt Assembly RH
      *2 Airbag Sensor Assembly

      Connect the connectors to the front seat outer belt assembly RH and airbag sensor assembly.

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

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

    4. Clear the DTCs.

      Click here


      Body Electrical > SRS Airbag > Clear DTCs

    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


      Body Electrical > SRS Airbag > Trouble Codes
      Result
      Proceed to
      DTC B1905/74, B1906/74, B1907/74 or B1908/74 is not output
      DTC B1905/74, B1906/74, B1907/74 or B1908/74 is output

      Tech Tips

      Codes other than DTC B1905/74, B1906/74, B1907/74 and B1908/74 may be output at this time, but they are not related to this check.


    DTC B1905/74, B1906/74, B1907/74 or B1908/74 is not output

    USE SIMULATION METHOD TO CHECK Click here

    DTC B1905/74, B1906/74, B1907/74 or B1908/74 is output

    REPLACE AIRBAG SENSOR ASSEMBLY Click here