AIRBAG SYSTEM, Diagnostic DTC:B1927/78

DTC Code DTC Name
B1927/78 Short to GND in Rear Pretensioner Squib LH Circuit

DESCRIPTION

The rear pretensioner squib LH circuit consists of the airbag sensor assembly and rear seat 3 point type outer belt assembly LH.

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

DTC B1927/78 is stored when a short to ground is detected in the rear pretensioner squib LH circuit.

DTC No. Detection Item DTC Detection Condition Trouble Area Test Mode / Check Mode
B1927/78 Short to GND in Rear Pretensioner Squib LH Circuit

  • The airbag sensor assembly detects a short to ground in the rear pretensioner squib LH circuit.

  • Rear pretensioner squib LH malfunction

  • Airbag sensor assembly malfunction

  • Floor wire

  • Rear pretensioner squib LH (Rear seat 3 point type outer belt assembly LH)

  • Airbag sensor assembly

 Applies to check mode

WIRING DIAGRAM

A01MHNIE04
*a Rear Pretensioner Squib LH (Rear Seat 3 Point Type Outer Belt Assembly LH)
*b Airbag Sensor Assembly

CAUTION / NOTICE / HINT

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 GTS.

    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 road or rough road.

    Click here

PROCEDURE


  1. CHECK CONNECTORS


    1. A01MH15C01
      *1 Front 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 and wait for at least 90 seconds.

    3. Check that the connectors are properly connected to the front seat outer belt assembly LH and airbag sensor assembly.

      OK
      The connectors are properly connected.

      Tech Tips

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

    4. Disconnect the connectors from the front 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 front seat outer belt assembly LH side) is not damaged.

      OK
      The connector locking 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.
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE FLOOR WIRE

    OK

  2. CHECK FLOOR WIRE


    1. A01MH7ZC01
      *1 Rear Seat 3 Point Type Outer Belt Assembly LH
      *2 Airbag Sensor Assembly
      *3 Floor Wire
      *a

      Front view of wire harness connector

      (to Rear Seat 3 Point Type Outer Belt Assembly LH)

      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
        P8-1 (RL+) - Body ground Always 1 MΩ or higher
        P8-2 (RL-) - Body ground Always 1 MΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE FLOOR WIRE

    OK

  3. CHECK DTC


    1. A01MFH4C01
      *1 Rear Seat 3 Point Type Outer Belt Assembly LH
      *2 Airbag Sensor Assembly
      *a

      Front view of wire harness connector

      (to Rear Seat 3 Point Type Outer Belt Assembly LH)
      *b Service Wire

      Connect the connectors to the airbag sensor assembly.

    2. Using a service wire, connect terminals 1 (RL+) and 2 (RL-) of connector C.

      Note

      Do not forcibly insert the service wire into the terminals of the connector when connecting the wire.

    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


      Body Electrical > SRS Airbag > Clear DTCs

    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


      Body Electrical > SRS Airbag > Trouble Codes
      OK
      DTC B1927/78 is not output.

      Tech Tips

      Codes other than DTC B1927/78 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 and wait for at least 90 seconds.

    11. Disconnect the service wire from connector C.

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE AIRBAG SENSOR ASSEMBLY Click here

    OK

  4. CHECK DTC


    1. A01MGT7C01
      *1 Rear Seat 3 Point Type Outer Belt Assembly LH
      *2 Airbag Sensor Assembly

      Connect the connectors to the rear seat 3 point type outer belt assembly LH.

    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


      Body Electrical > SRS Airbag > Clear DTCs

    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


      Body Electrical > SRS Airbag > Trouble Codes
      OK
      DTC B1927/78 is not output.

      Tech Tips

      Codes other than DTC B1927/78 may be output at this time, but they are not related to this check.

      Result
      Proceed to
      OK
      NG

    OK

    USE SIMULATION METHOD TO CHECK Click here

    NG

    REPLACE REAR SEAT 3 POINT TYPE OUTER BELT ASSEMBLY LH Click here