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DTC B1783: Rear Occupant Classification Sensor RH Circuit Malfunction: Procedure

  1. CHECK DTC 
    1. Turn the ignition switch on (IG).
    2. Clear the DTCs stored in the occupant classification ECU. Refer to DTC CHECK / CLEAR .
    3. for TMC made:

      Clear the DTCs stored in the center airbag sensor assembly. Refer to DTC CHECK / CLEAR .

    4. except TMC made:

      Clear the DTCs stored in the center airbag sensor assembly. Refer to DTC CHECK / CLEAR .

    5. Turn the ignition switch off.
    6. Turn the ignition switch on (IG).
    7. Check the DTCs. Refer to DTC CHECK / CLEAR .

      OK

      DTC B1783 is not output.

      HINT: 

      Codes other than DTC B1783 may be output at this time, but they are not related to this check.

    OK → See step   15 

    NG: Go to next step 

  2. CHECK CONNECTION OF CONNECTORS 
    1. Turn the ignition switch off.
    2. Disconnect the negative (-) terminal cable from the battery.
    3. Check that the connectors are properly connected to the occupant classification ECU and the rear occupant classification sensor RH.

      OK

      The connectors are properly connected.

    NG → CONNECT CONNECTORS PROPERLY, THEN GO TO   1 STEP 1 

    OK: Go to next step 

  3. CHECK FRONT SEAT WIRE RH (SHORT TO B+) 
    1. Disconnect the connectors from the occupant classification ECU and the rear occupant classification sensor RH.
      Fig 1: Identifying Front Seat Wire RH Connector Terminal Identification
      GTY202290Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Connect the negative (-) terminal cable to the battery.
    3. Turn the ignition switch on (IG).
    4. Measure the voltage according to the value(s) in the table below.

      Standard voltage

      for Power seat 

      for Manual seat 

      Tester connection Condition Specified condition
      T11-4 (SGD4) - Body ground Ignition switch on (IG) Below 1 V
      T11-6 (SVC4) - Body ground Ignition switch on (IG) Below 1 V
      T11-10 (SIG4) - Body ground Ignition switch on (IG) Below 1 V
      Tester connection Condition Specified condition
      d1-4 (SGD4) - Body ground Ignition switch on (IG) Below 1 V
      d1-10 (SIG4) - Body ground Ignition switch on (IG) Below 1 V
      d1-6 (SVC4) - Body ground Ignition switch on (IG) Below 1 V

    NG → REPAIR OR REPLACE FRONT SEAT WIRE RH 

    OK: Go to next step 

  4. CHECK FRONT SEAT WIRE RH (OPEN) 
    1. Turn the ignition switch off.
      Fig 2: Identifying Front Seat Wire RH (Open) Connector Terminal Identification
      GTY171388Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Disconnect the negative (-) terminal cable from the battery.
    3. Using a service wire, connect terminals 1 (SVC4) and 3 (SGD4), and connect terminals 2 (SIG4) and 3 (SGD4) of connector C.
    4. Measure the resistance according to the value(s) in the table below.

      Standard resistance

      for Power seat 

      for Manual seat 

      Tester connection Condition Specified condition
      T11-6 (SVC4) - T11-4 (SGD4) Always Below 1 Ω
      T11-10 (SIG4) - T11-4 (SGD4) Always Below 1 Ω
      Tester connection Condition Specified condition
      d1-10 (SIG4) - d1-4 (SGD4) Always Below 1 Ω
      d1-6 (SVC4) - d1-4 (SGD4) Always Below 1 Ω

    NG → REPAIR OR REPLACE FRONT SEAT WIRE RH 

    OK: Go to next step 

  5. CHECK FRONT SEAT WIRE RH (SHORT) 
    1. Disconnect the service wire from connector C.
      Fig 3: Identifying Front Seat Wire RH Connector Terminal Identification
      GTY202290Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the resistance according to the value(s) in the table below.

      Standard resistance

      for Power seat 

      for Manual seat 

      Tester connection Condition Specified condition
      T11-6 (SVC4) - T11-4 (SGD4) Always 1 MΩ or Higher
      T11-10 (SIG4) - T11-4 (SGD4) Always 1 MΩ or Higher
      T11-6 (SVC4) - T11-10 (SIG4) Always 1 MΩ or Higher
      Tester connection Condition Specified condition
      d1-10 (SIG4) - d1-4 (SGD4) Always 1 MΩ or Higher
      d1-6 (SVC4) - d1-4 (SGD4) Always 1 MΩ or Higher
      d1-10 (SIG4) - d1-6 (SVC4) Always 1 MΩ or Higher

    NG → REPAIR OR REPLACE FRONT SEAT WIRE RH 

    OK: Go to next step 

  6. CHECK FRONT SEAT WIRE RH (SHORT TO GROUND) 
    1. Measure the resistance according to the value(s) in the table below.
      Fig 4: Identifying Front Seat Wire RH Connector Terminal Identification
      GTY202290Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard resistance

      for Power seat 

      for Manual seat 

      Tester connection Condition Specified condition
      T11-4 (SGD4) - Body ground Always 1 MΩ or Higher
      T11-6 (SVC4) - Body ground Always 1 MΩ or Higher
      T11-10 (SIG4) - Body ground Always 1 MΩ or Higher
      Tester connection Condition Specified condition
      d1-4 (SGD4) - Body ground Always 1 MΩ or Higher
      d1-10 (SIG4) - Body ground Always 1 MΩ or Higher
      d1-6 (SVC4) - Body ground Always 1 MΩ or Higher

    NG → REPAIR OR REPLACE FRONT SEAT WIRE RH 

    OK: Go to next step 

  7. CHECK DTC 
    1. Connect the connectors to the occupant classification ECU and the rear occupant classification sensor RH.
    2. Connect the negative (-) terminal cable to the battery.
    3. Turn the ignition switch on (IG).
    4. Clear the DTCs stored in the occupant classification ECU. Refer to DTC CHECK / CLEAR .
    5. for TMC made:

      Clear the DTCs stored in the center airbag sensor assembly. Refer to DTC CHECK / CLEAR .

    6. except TMC made:

      Clear the DTCs stored in the center airbag sensor assembly. Refer to DTC CHECK / CLEAR .

    7. Turn the ignition switch off.
    8. Turn the ignition switch on (IG).
    9. Check the DTCs. Refer to DTC CHECK / CLEAR .

      OK

      DTC B1783 is not output.

      HINT: 

      Codes other than DTC B1783 may be output at this time, but they are not related to this check.

    OK → See step   15 

    NG: Go to next step 

  8. REPLACE OCCUPANT CLASSIFICATION ECU 
    1. Turn the ignition switch off.
    2. Disconnect the negative (-) terminal cable from the battery.
    3. Replace the occupant classification ECU. Refer to REMOVAL .

      HINT: 

      Perform the inspection using parts from a normal vehicle if possible.

    NEXT: Go to next step 

  9. PERFORM ZERO POINT CALIBRATION 
    1. Connect the negative (-) terminal cable to the battery.
    2. Connect Techstream to the DLC3.
    3. Turn the ignition switch on (IG).
    4. Using Techstream, perform "zero point calibration". Refer to INITIALIZATION .

      OK

      "Zero Point Calibration is complete." is displayed.

    NG → See step   12 

    OK: Go to next step 

  10. PERFORM SENSITIVITY CHECK 
    1. Using Techstream, perform "sensitivity check". Refer to INITIALIZATION .

      Standard value

      27 to 33 kg (59.52 to 72.75 lb)

    NG → See step   12 

    OK: Go to next step 

  11. CHECK DTC 
    1. Turn the ignition switch on (IG).
    2. Clear the DTCs stored in the occupant classification ECU. Refer to DTC CHECK / CLEAR .
    3. for TMC made:

      Clear the DTCs stored in the center airbag sensor assembly. Refer to DTC CHECK / CLEAR .

    4. except TMC made:

      Clear the DTCs stored in the center airbag sensor assembly. Refer to DTC CHECK / CLEAR .

    5. Turn the ignition switch off.
    6. Turn the ignition switch on (IG).
    7. Check the DTCs. Refer to DTC CHECK / CLEAR .

      OK

      DTC B1783 is not output.

      HINT: 

      Codes other than DTC B1783 may be output at this time, but they are not related to this check.

    OK → END 

    NG: Go to next step 

  12. REPLACE FRONT SEAT ASSEMBLY RH 
    1. Turn the ignition switch off.
    2. Disconnect the negative (-) terminal cable from the battery.
    3. Replace the front seat assembly RH. Refer to REMOVAL for power seat or. Refer to REMOVAL for manual seat).

    NEXT: Go to next step 

  13. PERFORM ZERO POINT CALIBRATION 
    1. Connect the negative (-) terminal cable to the battery.
    2. Connect Techstream to the DLC3.
    3. Turn the ignition switch on (IG).
    4. Using Techstream, perform "zero point calibration". Refer to INITIALIZATION .

      OK

      "Zero Point Calibration is complete." is displayed.

    NEXT: Go to next step 

  14. PERFORM SENSITIVITY CHECK 
    1. Using Techstream, perform "sensitivity check". Refer to INITIALIZATION .

      Standard value

      27 to 33 kg (59.52 to 72.75 lb)

    NEXT → END 

  15. USE SIMULATION METHOD TO CHECK. Refer to  DIAGNOSIS SYSTEM 
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