OCCUPANT CLASSIFICATION SYSTEM, Diagnostic DTC:B1785

DTC Code DTC Name
B1785 Front Occupant Classification Sensor LH Collision Detection

DESCRIPTION

DTC B1785 is stored when the occupant detection ECU receives a collision detection signal sent by the front occupant classification sensor LH in the case of an accident.

DTC B1785 is also stored when the front seat assembly RH is subjected to a strong impact, even if an actual accident did not occur.

If the vehicle was not in a collision, but the occupant detection ECU receives a collision detection signal and stores DTC B1785, the DTC can be cleared by performing zero point calibration. Therefore, if DTC B1785 is output, first perform zero point calibration.

DTC No. Detection Item DTC Detection Condition Trouble Area
B1785 Front Occupant Classification Sensor LH Collision Detection

  • Front occupant classification sensor LH sensed large load.

  • Front seat adjuster assembly RH malfunction

 Front occupant classification sensor LH (Front seat adjuster assembly RH)*

CAUTION / NOTICE / HINT

CAUTION:

When this DTC is stored, repair of the malfunction indicated can only be performed by initializing the occupant detection ECU or replacing the front seat adjuster assembly RH. Do not replace the occupant detection ECU to repair the malfunction indicated by this DTC.

If the occupant detection ECU is replaced, this DTC will not be output but the occupant detection system may not function properly.

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

When DTC B165A/32 is stored as a result of troubleshooting for the airbag system, check the DTCs stored in the occupant detection ECU. When DTC B1785 is output, perform troubleshooting for this DTC first.

PROCEDURE


  1. PERFORM ZERO POINT CALIBRATION


    1. Using the GTS, perform Zero Point Calibration.

      Click here


      Body Electrical > Occupant Detection > Utility
      Tester Display
      Zero Point Calibration
      OK
      "Zero Point Calibration is complete." is displayed.
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE FRONT SEAT ADJUSTER ASSEMBLY RH Click here

    OK

  2. CHECK DTC


    1. Clear the DTCs stored in the occupant detection ECU.

      Click here


      Body Electrical > Occupant Detection > Clear DTCs

    2. Clear the DTCs stored in the airbag sensor assembly.

      Click here


      Body Electrical > SRS Airbag > Clear DTCs

    3. Turn the power switch off.

    4. Turn the power switch on (IG), and wait for at least 10 seconds.

    5. Check for DTCs.

      Click here


      Body Electrical > Occupant Detection > Trouble Codes
      OK
      DTC B1785 is not output.

      Tech Tips

      Codes other than DTC B1785 may be output at this time, but they are not related to this check.

    6. Turn the power switch off.

      Result
      Proceed to
      OK
      NG

    OK

    END

    NG

  3. REPLACE FRONT SEAT ADJUSTER ASSEMBLY RH


    1. Turn the power switch off.

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

    3. Replace the front seat adjuster assembly RH.

      Click here

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

      Result
      Proceed to
      NEXT

    NEXT

  4. PERFORM ZERO POINT CALIBRATION


    1. Using the GTS, perform Zero Point Calibration.

      Click here


      Body Electrical > Occupant Detection > Utility
      Tester Display
      Zero Point Calibration
      Result
      Proceed to
      NEXT

    NEXT

    END

  5. REPLACE FRONT SEAT ADJUSTER ASSEMBLY RH


    1. Turn the power switch off.

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

    3. Replace the front seat adjuster assembly RH.

      Click here

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

      Result
      Proceed to
      NEXT

    NEXT

  6. PERFORM ZERO POINT CALIBRATION


    1. Using the GTS, perform Zero Point Calibration.

      Click here


      Body Electrical > Occupant Detection > Utility
      Tester Display
      Zero Point Calibration
      Result
      Proceed to
      NEXT

    NEXT

    END