AIRBAG SYSTEM, Diagnostic DTC:B1925/78, B1926/78, B1927/78, B1928/78

DTC Code DTC Name
B1925/78 Short in Rear Pretensioner Squib LH Circuit
B1926/78 Open in Rear Pretensioner Squib LH Circuit
B1927/78 Short to GND in Rear Pretensioner Squib LH Circuit
B1928/78 Short to B+ in Rear Pretensioner Squib LH Circuit

DESCRIPTION

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

The airbag sensor assembly uses this circuit to deploy the seat belt pretensioner when deployment conditions are met.

These DTCs are stored when a malfunction is detected in the rear pretensioner squib LH circuit.

DTC No. DTC Detection Condition Trouble Area
B1925/78
  • The airbag sensor assembly receives a line short circuit signal in the rear pretensioner squib LH circuit during primary check.

  • Rear pretensioner squib LH malfunction

  • Airbag sensor assembly malfunction


  • Floor wire

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

  • Airbag sensor assembly

B1926/78
  • The airbag sensor assembly receives an open circuit signal in the rear pretensioner squib LH circuit.

  • Rear pretensioner squib LH malfunction

  • Airbag sensor assembly malfunction

B1927/78
  • The airbag sensor assembly receives a short circuit to ground signal in the rear pretensioner squib LH circuit.

  • Rear pretensioner squib LH malfunction

  • Airbag sensor assembly malfunction

B1928/78
  • The airbag sensor assembly receives a short circuit to B+ signal in the rear pretensioner squib LH circuit.

  • Rear pretensioner squib LH malfunction

  • Airbag sensor assembly malfunction

WIRING DIAGRAM

A003ZQ7E75

INSPECTION PROCEDURE

Note

After turning the power switch off, waiting time may be required before disconnecting the cable from the negative (-) auxiliary battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) auxiliary battery terminal notices before proceeding with work Click here.

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. A003YH6E12
      Text in Illustration
      *1 Rear Seat Outer Belt Assembly LH
      *2 Airbag Sensor Assembly
      *3 Floor Wire

      Turn the power switch off.

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

      CAUTION:

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

    3. Check that the connectors are properly connected to the rear seat outer belt assembly LH and 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 LH and 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 LH 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
    OK
  2. CHECK REAR SEAT OUTER BELT ASSEMBLY LH (REAR PRETENSIONER SQUIB LH)


    1. A003VDEE13
      Text in Illustration
      *1 Rear Seat Outer Belt Assembly LH
      *2 Airbag Sensor Assembly
      *3 Connector C
      *a

      Front view of wire harness connector

      (to Rear Seat Outer Belt Assembly LH)

      Connect the connector to the 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 LH (rear pretensioner squib LH) for measurement, as this may lead to a serious injury due to pretensioner 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 (-) auxiliary battery terminal.

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

    5. Clear the DTCs stored in 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 B1925/78, B1926/78, B1927/78 or B1928/78 is not output.

      Tech Tips

      Codes other than DTCs B1925/78, B1926/78, B1927/78 and B1928/78 may be output at this time, but they are not related to this check.

    9. Turn the power switch off.

    10. Disconnect the cable from the negative (-) auxiliary battery terminal.

      CAUTION:

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

    11. Disconnect SST from connector C.


    NG
    OK
  3. CHECK FLOOR WIRE (REAR PRETENSIONER SQUIB LH CIRCUIT)


    1. A003Y4NE21
      Text in Illustration
      *1 Rear Seat Outer Belt Assembly LH
      *2 Airbag Sensor Assembly
      *3 Floor Wire
      *4 Connector C
      *a

      Front view of wire harness connector

      (to Rear Seat Outer Belt Assembly LH)

      Disconnect the floor wire from the airbag sensor assembly.

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


      1. Connect the cable to the negative (-) auxiliary 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
        P30-1 (RL+) - Body ground Power switch on (IG) Below 1 V
        P30-2 (RL-) - Body ground Power switch on (IG) Below 1 V
    3. Check for an open in the circuit.


      1. Turn the power switch off.

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

        CAUTION:

        Wait at least 90 seconds after disconnecting the cable from the negative (-) auxiliary 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
        P30-1 (RL+) - P30-2 (RL-) Always Below 1 Ω
    4. 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
        P30-1 (RL+) - Body ground Always 1 MΩ or higher
        P30-2 (RL-) - Body ground Always 1 MΩ or higher
    5. 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
        P30-1 (RL+) - P30-2 (RL-) Always 1 MΩ or higher
      3. Restore the released activation prevention mechanism of connector B to the original condition.


    NG
    OK
  4. CHECK DTC


    1. A003WXYE05
      Text in Illustration
      *1 Rear Seat Outer Belt Assembly LH
      *2 Airbag Sensor Assembly

      Connect the connectors to the rear seat outer belt assembly LH and airbag sensor assembly.

    2. Connect the cable to the negative (-) auxiliary battery terminal.

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

    4. Clear the DTCs stored in memory Click here.

    5. Turn the power switch off.

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

    7. Check for DTCs Click here.

      OK
      DTC B1925/78, B1926/78, B1927/78 or B1928/78 is not output.

      Tech Tips

      Codes other than DTCs B1925/78, B1926/78, B1927/78 and B1928/78 may be output at this time, but they are not related to this check.


    NG
    OK