AIRBAG SYSTEM, Diagnostic DTC:B1900/73,B1901/73,B1902/73 and 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 and front seat outer belt 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 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 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 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 malfunction.

  • No. 2 floor wire

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

  • Center airbag sensor assembly

B1902/73

One of the following conditions is met:

  • The center airbag sensor 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 malfunction.

  • No. 2 floor wire

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

  • Center airbag sensor assembly

B1903/73

One of the following conditions is met:

  • The center airbag sensor 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 malfunction.

  • No. 2 floor wire

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

  • Center airbag sensor assembly

WIRING DIAGRAM

C178002E38

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).

Tip:

To perform the simulation method, enter check mode (signal check) with the intelligent tester (Click here), 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 RH (FRONT PRETENSIONER SQUIB RH)

    1. U123061E02

      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 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 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.

    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, B1901, B1902 or B1903 is not output.

      Tip:

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

      Table 1. Text in Illustration

      *1

      Front Pretensioner Squib RH

      *2

      Center Airbag Sensor

      *3

      Front view of wire harness connector

      (to Front Pretensioner Squib RH)

      *4

      Connector C

    09843-18061

    REPLACE FRONT SEAT OUTER BELT ASSEMBLY RH

    (Click here)

  2. CHECK CONNECTOR

    1. 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 RH side) is not damaged.

      OK

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

    REPLACE NO. 2 FLOOR WIRE

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

    1. U123062E02

      Disconnect the connector from the center airbag sensor.

    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

      O2-1 (R+) - Body ground

      Ignition switch ON

      Below 1 V

      O2-2 (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

      O2-1 (R+) - O2-2 (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

      O2-1 (R+) - O2-2 (R-)

      Always

      1 MΩ or higher

      O2-1 (R+) - Body ground

      Always

      1 MΩ or higher

      O2-2 (R-) - Body ground

      Always

      1 MΩ or higher
    Table 2. Text in Illustration

    *1

    Front Pretensioner Squib RH

    *2

    No. 2 Floor Wire

    *3

    Center Airbag Sensor

    *4

    Front view of wire harness connector

    (to Front Pretensioner Squib RH)

    *5

    Connector C

    REPLACE NO. 2 FLOOR WIRE

  4. CHECK CENTER AIRBAG SENSOR

    1. C198556E02

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

    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, B1901, B1902 or B1903 is not output.

      Tip:

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

      Table 3. Text in Illustration

      *1

      Front Pretensioner Squib RH

      *2

      Center Airbag Sensor

    USE SIMULATION METHOD TO CHECK

    (Click here)

    REPLACE CENTER AIRBAG SENSOR ASSEMBLY

    (Click here)