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 RH circuit consists of the center airbag sensor assembly 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 RH circuit.

DTC Code DTC Detection Condition Trouble Area
B1900/73

One of the following conditions is met:


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

  • A front pretensioner RH malfunction.

  • A center airbag sensor assembly malfunction.

  • Engine room main wire

  • Front seat outer belt assembly RH

  • Center airbag sensor assembly
B1901/73

One of the following conditions is met:


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

  • A front pretensioner RH malfunction.

  • A center airbag sensor assembly malfunction.

  • Engine room main wire

  • Front seat outer belt assembly RH

  • Center airbag sensor assembly
B1902/73

One of the following conditions is met:


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

  • A front pretensioner RH malfunction.

  • A center airbag sensor assembly malfunction.

  • Engine room main wire

  • Front seat outer belt assembly RH

  • Center airbag sensor assembly
B1903/73

One of the following conditions is met:


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

  • A front pretensioner RH malfunction.

  • A center airbag sensor assembly malfunction.

  • Engine room main wire

  • Front seat outer belt assembly RH

  • Center airbag sensor assembly

WIRING DIAGRAM

A003CIAE04

INSPECTION PROCEDURE

Note


  • 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 center airbag sensor 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 RH


    1. A003BR5E13
      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 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 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 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 ON, and wait for at least 60 seconds.

    10. Check for DTCs Click here.

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

      Tech Tips

      Codes other than DTC B1900, B1901, B1902 and B1903 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.


    NG

    CHECK CONNECTORS Click here

    OK

    REPLACE FRONT SEAT OUTER BELT ASSEMBLY RH Click here

  2. CHECK CONNECTORS


    1. Disconnect the connectors from the center airbag sensor assembly.

    2. A003HZME04
      Text in Illustration
      *1 Front Seat Outer Belt Assembly RH
      *2 Engine Room Main Wire
      *3 Center Airbag Sensor Assembly

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

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

    NG

    REPLACE ENGINE ROOM MAIN WIRE

    OK

  3. CHECK ENGINE ROOM MAIN WIRE


    1. A003I57E13
      Text in Illustration
      *1 Front Seat Outer Belt Assembly RH
      *2 Engine Room Main Wire
      *3 Center 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
      B25-1 (R+) - Body ground Ignition switch ON Below 1 V
      B25-2 (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
      B25-1 (R+) - B25-2 (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
      B25-1 (R+) - B25-2 (R-) Always 1 MΩ or higher
      B25-1 (R+) - Body ground Always 1 MΩ or higher
      B25-2 (R-) - Body ground Always 1 MΩ or higher

    NG

    REPLACE ENGINE ROOM MAIN WIRE

    OK

  4. CHECK DTC


    1. A003CTPE02
      Text in Illustration
      *1 Front Seat Outer Belt Assembly RH
      *2 Center Airbag Sensor Assembly

      Connect the connectors to the front seat outer belt 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 ON, and wait for at least 60 seconds.

    4. Clear the DTCs stored in memory Click here.

    5. Turn the ignition switch off.

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

    7. Check for DTCs Click here.

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

      Tech Tips

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


    NG

    REPLACE CENTER AIRBAG SENSOR ASSEMBLY Click here

    OK

    USE SIMULATION METHOD TO CHECK Click here