AIRBAG SYSTEM, 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 squib RH circuit consists of the center 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 squib RH circuit.

DTC Code DTC Detection Condition Trouble Area
B1900/73

One of the following conditions is met:


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

  • A front pretensioner squib RH malfunction.

  • A center airbag sensor assembly malfunction.

  • No. 2 floor wire

  • Front seat outer belt assembly RH (Front pretensioner squib RH)

  • Center airbag sensor assembly
B1901/73

One of the following conditions is met:


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

  • A front pretensioner squib RH malfunction.

  • A center airbag sensor assembly malfunction.
B1902/73

One of the following conditions is met:


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

  • A front pretensioner squib RH malfunction.

  • A center airbag sensor assembly malfunction.
B1903/73

One of the following conditions is met:


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

  • A front pretensioner squib RH malfunction.

  • A center airbag sensor assembly malfunction.

WIRING DIAGRAM

A0052YTE04
*a Front Seat Outer Belt Assembly RH
*b Center Airbag Sensor Assembly

CAUTION / NOTICE / HINT

Note


  • After turning the ignition switch off, waiting time may be required before disconnecting the cable from the battery terminal. Therefore, make sure to read the disconnecting the cable from the battery terminal notice 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 intelligent tester (See page ), and then wiggle each connector of the airbag system or drive the vehicle on various types of roads Click here.

PROCEDURE


  1. CHECK FRONT SEAT OUTER BELT ASSEMBLY RH (FRONT PRETENSIONER SQUIB RH)


    1. A0052VME01
      Text in Illustration
      *1 Front Seat Outer Belt Assembly RH
      *2 Center 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 (front pretensioner 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 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.

    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.

      OK
      DTC B1900/73, B1901/73, B1902/73 or B1903/73 is not output.

      Tech Tips

      Codes other than DTC B1900/73, B1901/73, B1902/73 and B1903/73 may be output at this time, but they are not related to this check.


    OK

    REPLACE FRONT SEAT OUTER BELT ASSEMBLY RH Click here

    NG

  2. CHECK CONNECTORS


    1. A00575AE02
      Text in Illustration
      *1 Front Seat Outer Belt Assembly RH
      *2 Center Airbag Sensor Assembly

      Turn the ignition switch off.

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

    3. Disconnect SST from connector C.

    4. Check that the No. 2 floor wire connector (on the front seat outer belt assembly RH side) is not damaged.

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

    NG

    REPLACE NO. 2 FLOOR WIRE

    OK

  3. CHECK NO. 2 FLOOR WIRE (FRONT PRETENSIONER SQUIB RH CIRCUIT)


    1. A0056X9E02
      Text in Illustration
      *1 Front Seat Outer Belt Assembly RH
      *2 No. 2 Floor Wire
      *3 Center Airbag Sensor Assembly
      *4 Connector C
      *a

      Front view of wire harness connector

      (to Front Seat Outer Belt Assembly RH)

      Disconnect the connector from the center airbag sensor assembly.

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

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      H2-1 (R+) - Body ground Ignition switch ON Below 1 V
      H2-2 (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
      H2-1 (R+) - H2-2 (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
      H2-1 (R+) - H2-2 (R-) Always 1 MΩ or higher
      H2-1 (R+) - Body ground Always 1 MΩ or higher
      H2-2 (R-) - Body ground Always 1 MΩ or higher

    NG

    REPLACE NO. 2 FLOOR WIRE

    OK

  4. CHECK CENTER AIRBAG SENSOR ASSEMBLY


    1. A0052U4E02
      Text in Illustration
      *1 Front Seat Outer Belt Assembly RH
      *2 Center Airbag Sensor Assembly

      Connect the connectors to the front seat outer belt assembly RH and center 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 stored in the 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 B1900/73, B1901/73, B1902/73 or B1903/73 is not output.

      Tech Tips

      Codes other than DTC B1900/73, B1901/73, B1902/73 and B1903/73 may be output at this time, but they are not related to this check.


    OK

    USE SIMULATION METHOD TO CHECK Click here

    NG

    REPLACE CENTER AIRBAG SENSOR ASSEMBLY Click here