AIRBAG SYSTEM, Diagnostic DTC:B1656/38

DTC Code DTC Name
B1656/38 Seat Belt Buckle Switch LH Circuit Malfunction

DESCRIPTION

The seat belt buckle switch LH circuit consists of the airbag sensor assembly and front seat inner belt assembly LH.

DTC B1656/38 is stored when a malfunction is detected in the seat belt buckle switch LH circuit.

DTC No. DTC Detection Condition Trouble Area
B1656/38

  • The airbag sensor assembly receives a line short circuit signal, an open circuit signal, a short circuit to ground signal or a short circuit to B+ signal in the seat belt buckle switch LH circuit.

  • Front seat inner belt assembly LH malfunction

  • Airbag sensor assembly malfunction

  • Floor wire

  • Front seat inner belt assembly LH (Seat belt buckle switch LH)

  • Airbag sensor assembly

WIRING DIAGRAM

B001M81E01

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.

PROCEDURE


  1. CHECK CONNECTORS


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

      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 airbag sensor assembly and front seat inner belt assembly LH.

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

      OK
      The terminals are not deformed or damaged.

    NG

    REPLACE FLOOR WIRE

    OK

  2. CHECK FLOOR WIRE (OPEN)

    SST
    09843-18040

    1. w/o Rear Pretensioner

      B001MOIE01

      1. Using SST, connect terminals 11 (LBE+) and 12 (LBE-) of connector B.

        Note

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

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

        Standard Resistance
        Tester Connection Condition Specified Condition
        P3-2 (LBE+) - P3-1 (LBE-) Always Below 1 Ω

      3. Disconnect SST from connector B.

        Text in Illustration
        *1 Front Seat Inner Belt Assembly LH *2 Airbag Sensor Assembly
        *3 Floor Wire *4 Connector B
        *5 Connector C - -
        *a

        Front view of wire harness connector

        (to Airbag Sensor Assembly)

        		 *b

        Front view of wire harness connector

        (to Front Seat Inner Belt Assembly LH)
      SST
      09843-18040

    2. w/ Rear Pretensioner

      B001L13E01

      1. Using SST, connect terminals 10 (LBE+) and 18 (LBE-) of connector B.

        Note

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

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

        Standard Resistance
        Tester Connection Condition Specified Condition
        P3-2 (LBE+) - P3-1 (LBE-) Always Below 1 Ω

      3. Disconnect SST from connector B.

        Text in Illustration
        *1 Front Seat Inner Belt Assembly LH *2 Airbag Sensor Assembly
        *3 Floor Wire *4 Connector B
        *5 Connector C - -
        *a

        Front view of wire harness connector

        (to Airbag Sensor Assembly)

        		 *b

        Front view of wire harness connector

        (to Front Seat Inner Belt Assembly LH)

    NG

    REPLACE FLOOR WIRE

    OK

  3. CHECK FLOOR WIRE (SHORT)


    1. B001LLME01
      Text in Illustration
      *1 Front Seat Inner Belt Assembly LH
      *2 Airbag Sensor Assembly
      *3 Floor Wire
      *4 Connector C
      *a

      Front view of wire harness connector

      (to Front Seat Inner Belt Assembly LH)

      w/o Rear Pretensioner


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

        Standard Resistance
        Tester Connection Condition Specified Condition
        P3-2 (LBE+) - P3-1 (LBE-) Always 1 MΩ or higher
    2. B001KC5E01
      Text in Illustration
      *1 Front Seat Inner Belt Assembly LH
      *2 Airbag Sensor Assembly
      *3 Floor Wire
      *4 Connector C
      *a

      Front view of wire harness connector

      (to Front Seat Inner Belt Assembly LH)

      w/ Rear Pretensioner


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

        Standard Resistance
        Tester Connection Condition Specified Condition
        P3-2 (LBE+) - P3-1 (LBE-) Always 1 MΩ or higher

    NG

    REPLACE FLOOR WIRE

    OK

  4. CHECK FLOOR WIRE (SHORT TO B+)


    1. B001LLME01
      Text in Illustration
      *1 Front Seat Inner Belt Assembly LH
      *2 Airbag Sensor Assembly
      *3 Floor Wire
      *4 Connector C
      *a

      Front view of wire harness connector

      (to Front Seat Inner Belt Assembly LH)

      w/o Rear Pretensioner


      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
        P3-2 (LBE+) - Body ground Power switch on (IG) Below 1 V
        P3-1 (LBE-) - Body ground Power switch on (IG) Below 1 V
    2. B001KC5E01
      Text in Illustration
      *1 Front Seat Inner Belt Assembly LH
      *2 Airbag Sensor Assembly
      *3 Floor Wire
      *4 Connector C
      *a

      Front view of wire harness connector

      (to Front Seat Inner Belt Assembly LH)

      w/ Rear Pretensioner


      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
        P3-2 (LBE+) - Body ground Power switch on (IG) Below 1 V
        P3-1 (LBE-) - Body ground Power switch on (IG) Below 1 V

    NG

    REPLACE FLOOR WIRE

    OK

  5. CHECK FLOOR WIRE (SHORT TO GROUND)


    1. B001LLME01
      Text in Illustration
      *1 Front Seat Inner Belt Assembly LH
      *2 Airbag Sensor Assembly
      *3 Floor Wire
      *4 Connector C
      *a

      Front view of wire harness connector

      (to Front Seat Inner Belt Assembly LH)

      w/o Rear Pretensioner


      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
        P3-2 (LBE+) - Body ground Always 1 MΩ or higher
        P3-1 (LBE-) - Body ground Always 1 MΩ or higher
    2. B001KC5E01
      Text in Illustration
      *1 Front Seat Inner Belt Assembly LH
      *2 Airbag Sensor Assembly
      *3 Floor Wire
      *4 Connector C
      *a

      Front view of wire harness connector

      (to Front Seat Inner Belt Assembly LH)

      w/ Rear Pretensioner


      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
        P3-2 (LBE+) - Body ground Always 1 MΩ or higher
        P3-1 (LBE-) - Body ground Always 1 MΩ or higher

    NG

    REPLACE FLOOR WIRE

    OK

  6. CHECK DTC


    1. B001LA8E01
      Text in Illustration
      *A w/o Rear Pretensioner
      *B w/ Rear Pretensioner
      *1 Front Seat Inner Belt Assembly LH
      *2 Airbag Sensor Assembly

      Connect the connectors to the airbag sensor assembly and front seat inner 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.

    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 B1656/38 is not output.

      Tech Tips

      Codes other than DTC B1656/38 may be output at this time, but they are not related to this check.


    OK

    USE SIMULATION METHOD TO CHECK Click here

    NG

  7. CHECK FRONT SEAT INNER BELT ASSEMBLY LH


    1. B001LA8E01
      Text in Illustration
      *A w/o Rear Pretensioner
      *B w/ Rear Pretensioner
      *1 Front Seat Inner Belt Assembly LH
      *2 Airbag Sensor Assembly

      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. Replace the front seat inner belt assembly LH with a known good one (See page for Manual Seat, Click here for Power Seat).

      Tech Tips

      Perform the following inspection using known good parts from another vehicle if possible.

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

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

    6. Clear the DTCs stored in memory Click here.

    7. Turn the power switch off.

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

    9. Check for DTCs Click here.

      OK
      DTC B1656/38 is not output.
      Result
      Result Proceed to
      OK (for Manual Seat) A
      OK (for Power Seat) B
      NG C

      Tech Tips

      Codes other than DTC B1656/38 may be output at this time, but they are not related to this check.

    10. Turn the power switch off.

    11. 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.

    12. Restore the front seat inner belt assembly LH that was installed for testing to its original location (Replace the front seat inner belt assembly LH with a known good one (See page for Manual Seat, Click here for Power Seat).


    A

    REPLACE FRONT SEAT INNER BELT ASSEMBLY LH Click here

    B

    REPLACE FRONT SEAT INNER BELT ASSEMBLY LH Click here

    C

    REPLACE AIRBAG SENSOR ASSEMBLY Click here