AIRBAG SYSTEM, Diagnostic DTC:B1920/77, B1921/77, B1922/77, B1923/77

DTC Code DTC Name
B1920/77 Short in Rear Pretensioner Squib RH Circuit
B1921/77 Open in Rear Pretensioner Squib RH Circuit
B1922/77 Short to GND in Rear Pretensioner Squib RH Circuit
B1923/77 Short to B+ in Rear Pretensioner Squib RH Circuit

DESCRIPTION

The rear pretensioner squib RH circuit consists of the center airbag sensor assembly and rear seat outer belt assembly RH.

This circuit instructs the SRS to deploy when deployment conditions are met.

These DTCs are recorded when a malfunction is detected in the rear pretensioner squib RH circuit.

DTC No. DTC Detection Condition Trouble Area
B1920/77

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

  • Rear pretensioner squib RH malfunction

  • Center airbag sensor assembly malfunction

  • Floor wire

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

  • Center airbag sensor assembly
B1921/77

  • The center airbag sensor assembly receives an open circuit signal in the rear pretensioner squib RH circuit.

  • Rear pretensioner squib RH malfunction

  • Center airbag sensor assembly malfunction

  • Floor wire

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

  • Center airbag sensor assembly
B1922/77

  • The center airbag sensor assembly receives a short circuit to ground signal in the rear pretensioner squib RH circuit.

  • Rear pretensioner squib RH malfunction

  • Center airbag sensor assembly malfunction

  • Floor wire

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

  • Center airbag sensor assembly
B1923/77

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

  • Rear pretensioner squib RH malfunction

  • Center airbag sensor assembly malfunction

  • Floor wire

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

  • Center airbag sensor assembly

WIRING DIAGRAM

A01NCZ5E14

INSPECTION PROCEDURE

Tech Tips


  • Perform the simulation method by selecting check mode (Signal Check) using the intelligent tester Click here.

  • After selecting check mode (Signal Check), perform the simulation method by wiggling each connector of the airbag system or driving the vehicle on a city or rough road Click here.

PROCEDURE


  1. CHECK CONNECTORS


    1. A01NH5BE01
      Text in Illustration
      *1 Rear Pretensioner Squib RH
      *2 Center Airbag Sensor Assembly
      *3 Floor Wire

      Turn the power switch off.

    2. Disconnect the cable from the negative (-) battery terminal.

      Note

      Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.

    3. Check that the connectors are properly connected to the rear seat outer belt assembly RH and center airbag sensor assembly.

      OK
      The connectors are properly connected.

      Tech Tips

      If the connectors are not connected securely, reconnect the connectors and proceed to the next inspection.

    4. Disconnect the connectors from the rear seat outer belt assembly RH and center airbag sensor assembly.

    5. Check that the terminals of the connectors are not damaged.

      OK
      The terminals are not deformed or damaged.

    6. Check that the floor wire connector (on the rear 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.

    7. Check that the short spring for the floor wire with the activation prevention mechanism is not deformed or damaged.

      OK
      The short spring is not deformed or damaged.

    NG

    REPLACE FLOOR WIRE

    OK

  2. CHECK REAR SEAT OUTER BELT ASSEMBLY RH (REAR PRETENSIONER SQUIB RH)


    1. A01NGRRE02
      Text in Illustration
      *1 Rear Pretensioner Squib RH
      *2 Center Airbag Sensor Assembly
      *3

      Front view of wire harness connector

      (to Rear Seat Outer Belt Assembly RH)
      *4 Connector C

      Connect the connector to the center airbag sensor assembly.

    2. Connect SST (resistance 2.1 Ω) to connector C.

      CAUTION:

      Never connect the tester to the rear seat outer belt assembly RH (rear 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.

      • Insert SST straight into the terminals of the connector.

      SST
      09843-18061

    3. Connect the cable to the negative (-) battery terminal.

    4. Turn the power switch on (IG), and wait for at least 60 seconds.

    5. Clear the DTCs stored in the memory Click here.

    6. Turn the power switch off.

    7. Turn the power switch on (IG), and wait for at least 60 seconds.

    8. Check for DTCs Click here.

      OK
      DTC B1920, B1921, B1922, B1923, or 77 is not output.

      Tech Tips

      Codes other than DTC B1920, B1921, B1922, B1923, and 77 may be output at this time, but they are not related to this check.


    NG

    CHECK FLOOR WIRE (REAR PRETENSIONER SQUIB CIRCUIT RH) Click here

    OK

    REPLACE REAR SEAT OUTER BELT ASSEMBLY RH Click here

  3. CHECK FLOOR WIRE (REAR PRETENSIONER SQUIB CIRCUIT RH)


    1. A01NHJ3E02
      Text in Illustration
      *1 Rear Pretensioner Squib RH
      *2 Center Airbag Sensor Assembly
      *3 Floor Wire
      *4

      Front view of wire harness connector

      (to Rear Seat Outer Belt Assembly RH)
      *5 Connector C

      Turn the power switch off.

    2. Disconnect the cable from the negative (-) battery terminal.

      Note

      Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.

    3. Disconnect SST from connector C.

    4. Disconnect the floor wire from the center airbag sensor assembly.

    5. Check for a short to B+ in the circuit.


      1. Connect the cable to the negative (-) battery terminal.

      2. Turn the power switch on (IG).

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

        Standard Voltage
        Tester Connection Switch Condition Specified Condition
        O21-1 (RR+) - Body ground Power switch on (IG) Below 1 V
        O21-2 (RR-) - Body ground Power switch on (IG) Below 1 V

    6. Check for an open in the circuit.


      1. Turn the power switch off.

      2. Disconnect the cable from the negative (-) battery terminal.

        Note

        Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.

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

        Standard Resistance
        Tester Connection Condition Specified Condition
        O21-1 (RR+) - O21-2 (RR-) Always Below 1 Ω

    7. Check for a short to ground in the circuit.


      1. Measure the resistance according to the value(s) in the table below.

        Standard Resistance
        Tester Connection Condition Specified Condition
        O21-1 (RR+) - Body ground Always 1 MΩ or higher
        O21-2 (RR-) - Body ground Always 1 MΩ or higher

    8. Check for a short in the circuit.


      1. Release the activation prevention mechanism built into connector B Click here.

      2. Measure the resistance according to the value(s) in the table below.

        Standard Resistance
        Tester Connection Condition Specified Condition
        O21-1 (RR+) - O21-2 (RR-) Always 1 MΩ or higher

    NG

    REPLACE FLOOR WIRE

    OK

  4. CHECK CENTER AIRBAG SENSOR ASSEMBLY


    1. A01NHVHE01
      Text in Illustration
      *1 Rear Pretensioner Squib RH
      *2 Center Airbag Sensor Assembly

      Restore the released activation prevention mechanism of connector B to the original condition.

    2. Connect the connectors to the rear seat outer belt assembly RH and center airbag sensor assembly.

    3. Connect the cable to the negative (-) battery terminal.

    4. Turn the power switch on (IG), and wait for at least 60 seconds.

    5. Clear the DTCs stored in the memory Click here.

    6. Turn the power switch off.

    7. Turn the power switch on (IG), and wait for at least 60 seconds.

    8. Check for DTCs Click here.

      OK
      DTC B1920, B1921, B1922, B1923, or 77 is not output.

      Tech Tips

      Codes other than DTC B1920, B1921, B1922, B1923, and 77 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