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 center airbag sensor assembly and the front seat inner belt LH.

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

DTC Code Detection Condition Trouble Area
B1656/38

One of the following conditions is met:


  • The center 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 for 2 seconds.

  • Front seat inner belt LH malfunction

  • Center airbag sensor assembly malfunction

  • No. 2 floor wire

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

  • Center airbag sensor assembly

WIRING DIAGRAM

A01GZZ2E25

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.

  • When disconnecting the cable from the negative (-) auxiliary battery terminal while performing repairs, some systems need to be initialized after the cable is reconnected Click here.

PROCEDURE


  1. CHECK FOR DTC

    A01GW2OE57

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

    2. Clear the DTCs Click here.

    3. Turn the power switch OFF.

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

    5. Check for DTCs Click here.

      OK
      DTC B1656 is not output.

      Tech Tips

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


    NG

    CHECK CONNECTION OF CONNECTORS Click here

    OK

    USE SIMULATION METHOD TO CHECK Click here

  2. CHECK CONNECTION OF CONNECTORS


    1. Turn the power switch OFF.

    2. Disconnect the negative (-) terminal cable from the auxiliary battery, and wait for at least 90 seconds.

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

      OK
      The connectors are properly connected.

    NG

    CONNECT CONNECTORS PROPERLY

    OK

  3. CHECK CONNECTORS


    1. Disconnect the connectors from the center airbag sensor assembly and the front seat inner belt LH.

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

      OK
      The connectors are not deformed or damaged.

    NG

    REPLACE NO. 2 FLOOR WIRE

    OK

  4. CHECK NO. 2 FLOOR WIRE (CENTER AIRBAG SENSOR ASSEMBLY - FRONT SEAT INNER BELT LH)

    A01GWGNE05

    1. Connect the negative (-) terminal cable to the auxiliary battery, and wait for at least 2 seconds.

    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
      S17-1 (LBE+) - Body ground Power switch ON (IG) Below 1 V
      S17-3 (LBE-) - Body ground Power switch ON (IG) Below 1 V

    4. Turn the power switch OFF.

    5. Disconnect the negative (-) terminal cable from the auxiliary battery, 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
      S17-1 (LBE+) - S8-10 (LBE+) Always Below 1 Ω

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

      Standard resistance
      Tester Connection Condition Specified Condition
      S17-1 (LBE+) - Body ground Always 1 MΩ or higher
      S17-3 (LBE-) - Body ground Always Below 1 Ω

    NG

    REPLACE NO. 2 FLOOR WIRE

    OK

  5. CHECK FRONT SEAT INNER BELT LH

    A01GW2OE57

    1. Connect the connector to the center airbag sensor assembly and the front seat inner belt LH.

    2. Connect the negative (-) terminal cable to the auxiliary battery, and wait for at least 2 seconds.

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

    4. Clear the DTCs 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 is not output.

      Tech Tips

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


    NG

    REPLACE FRONT SEAT INNER BELT LH Click here

    OK

    USE SIMULATION METHOD TO CHECK Click here

  6. REPLACE FRONT SEAT INNER BELT LH


    1. Turn the power switch OFF.

    2. Disconnect the negative (-) terminal cable from the auxiliary battery, and wait for at least 90 seconds.

    3. Replace the front seat inner belt LH Click here.

      Tech Tips

      Perform the inspection using parts from a normally functioning vehicle if possible.


    NEXT

  7. CHECK CENTER AIRBAG SENSOR ASSEMBLY

    A01GW2OE57

    1. Connect the negative (-) terminal cable to the auxiliary battery, and wait for at least 2 seconds.

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

    3. Clear the DTCs Click here.

    4. Turn the power switch OFF.

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

    6. Check for DTCs Click here.

      OK
      DTC B1656 is not output.

      Tech Tips

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


    NG

    REPLACE CENTER AIRBAG SENSOR ASSEMBLY Click here

    OK

    REPLACE FRONT SEAT INNER BELT ASSEMBLY LH Click here