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OCCUPANT CLASSIFICATION SYSTEM, Diagnostic DTC:B1785

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DTC Code DTC Name
B1785 Front Occupant Classification Sensor LH Collision Detection
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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 seat adjuster assembly RH (Front occupant classification sensor LH)*

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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.

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Tip:

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.

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PROCEDURE


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    PERFORM ZERO POINT CALIBRATION


    1. Using the GTS, perform Zero Point Calibration.

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      1. Body Electrical > Occupant Detection > Utility
        Tester Display
        Zero Point Calibration




      OK
      "Zero Point Calibration is complete." is displayed.
      Result
      Proceed to
      OK
      NG

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    CHECK DTC


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

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      1. Body Electrical > Occupant Detection > Clear DTCs


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

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      1. 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.

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      1. Body Electrical > Occupant Detection > Trouble Codes


      OK
      DTC B1785 is not output.
      Tip:

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

      Result
      Proceed to
      OK
      NG

    • OK

      END (NORMAL AFTER PERFORMING ZERO POINT CALIBRATION)

    • NGClick here
  3. Click here

    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 with a new one.

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

      Result
      Proceed to
      NEXT

  4. Click here

    PERFORM ZERO POINT CALIBRATION


    1. Using the GTS, perform Zero Point Calibration.

      Click here


      1. Body Electrical > Occupant Detection > Utility
        Tester Display
        Zero Point Calibration




      Result
      Proceed to
      NEXT

    • NEXT

      END (FRONT SEAT ADJUSTER ASSEMBLY RH WAS DEFECTIVE)

  5. Click here

    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 with a new one.

      Click here

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

      Result
      Proceed to
      NEXT

  6. Click here

    PERFORM ZERO POINT CALIBRATION


    1. Using the GTS, perform Zero Point Calibration.

      Click here


      1. Body Electrical > Occupant Detection > Utility
        Tester Display
        Zero Point Calibration




      Result
      Proceed to
      NEXT

    • NEXT

      END (FRONT SEAT ADJUSTER ASSEMBLY RH WAS DEFECTIVE)