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Trouble in Passenger Airbag ON/OFF Indicator: Procedure

WARNING: This page is about a different car, the 2009 Lexus GS 460 and 2009 Lexus GS 350. However, it is still accessible from the selected car via links, so may be relevant.
  1. PERFORM ZERO POINT CALIBRATION 
    1. Connect the Techstream to the DLC3.
    2. Turn the engine switch on (IG).
    3. Using the Techstream, perform the zero point calibration. Refer to DIAGNOSIS SYSTEM .
    4. Turn the engine switch off.
    5. Turn the engine switch on (IG).
    6. Check for the DTCs of the occupant classification ECU. Refer to DTC CHECK / CLEAR .

    NEXT: Go to next step 

  2. CHECK FOR DTC 
    1. Turn the engine switch on (IG).
    2. Clear the DTCs stored in the occupant classification ECU. Refer to DTC CHECK / CLEAR .
    3. Clear the DTCs stored in the center airbag sensor. Refer to DTC CHECK / CLEAR .
    4. Turn the engine switch off.
    5. Turn the engine switch on (IG).
    6. Check for the DTCs. Refer to DTC CHECK / CLEAR .

      OK

      DTC B1797 is not output.

      HINT: 

      Codes other than B1797 may be output at this time, but they are not related to this check.

    NG → See step   18 

    OK: Go to next step 

  3. CHECK PASSENGER AIRBAG ON / OFF INDICATOR (PERFORM SENSITIVITY CHECK) 
    1. Perform the sensitivity check. Refer to DIAGNOSIS SYSTEM .

    NG → See step   4 

    OK → END 

  4. READ VALUE USING DATA LIST (PASSENGER SIDE BUCKLE SWITCH) 
    1. Turn the engine switch on (IG).
    2. Using the Techstream, read the DATA LIST. Refer to DATA LIST / ACTIVE TEST .
      1. Read the display when the passenger side buckle switch is operated.
        OCCUPANT CLASSIFICATION ECU:

        Tester Display Measurement Item / Range Normal Condition Specified Condition for Zero Point Calibration Diagnostic Note
        P BUCKLE SW Buckle switch (Passenger side) / SET, UNSET or NG SET: The seat belt is fastened
        UNSET: The seat belt is not fastened
        NG: Data is not determined
        UNSET -

        OK

        The Techstream display changes correctly in accordance with the operation of the buckle switch.

    NG → See step   10 

    OK: Go to next step 

  5. READ VALUE USING DATA LIST (SEAT BELT TENSION SENSOR) 
    1. Fasten the passenger side seat belt.
    2. Turn the engine switch on (IG).
    3. Using the Techstream, read the value of the DATA LIST. Refer to DATA LIST / ACTIVE TEST .
      OCCUPANT CLASSIFICATION ECU:

      Tester Display Measurement Item / Range Normal Condition Specified Condition for Zero Point Calibration Diagnostic Note
      FILTERED TENSION Filtered belt tension output / Min.: 0, Max.: 255 39 to 229 39 to 64
      (no load)
      -

      OK

      When there is no tension on belt, 39 to 229 is displayed on Techstream.

    NG → See step   14 

    OK: Go to next step 

  6. CHECK CONNECTOR 
    1. Disconnect the connectors from the occupant classification ECU and the detection sensor.
    2. Check that the connectors (on the center airbag sensor and occupant detection sensor side) are not damaged.

      OK

      Connectors are not deformed or damaged.

    NG → REPAIR OR REPLACE FRONT SEAT WIRE RH 

    OK: Go to next step 

  7. REPLACE FRONT SEAT CUSHION ASSEMBLY 
    1. Turn the engine switch off.
    2. Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.
    3. Replace the front seat cushion (with occupant classification ECU and occupant detection sensor). Refer to DISASSEMBLY .
    4. Connect the negative (-) terminal cable to the battery.

    NEXT: Go to next step 

  8. PERFORM ZERO POINT CALIBRATION 
    1. Connect the Techstream to the DLC3.
    2. Turn the engine switch on (IG).
    3. Using the Techstream, perform the zero point calibration. Refer to INITIALIZATION .
    4. Turn the engine switch off.
    5. Turn the engine switch on (IG).
    6. Clear the DTCs stored in the occupant classification ECU. Refer to DTC CHECK / CLEAR .

      HINT: 

      If the DTCs are not cleared at this time, past DTCs will remain.

    NEXT: Go to next step 

  9. PERFORM SENSITIVITY CHECK 
    1. Perform the sensitivity check. Refer to INITIALIZATION .

      OK

      Passenger airbag ON/OFF indicator changes correctly in accordance with the operation.

    NG → REPLACE OCCUPANT CLASSIFICATION ECU 

    OK → END 

  10. CHECK CONNECTOR 
    1. Disconnect the connectors from the occupant classification ECU and front seat inner belt RH.
    2. Check that the connectors (on the center airbag sensor side and front seat inner belt RH) are not damaged.

      OK

      Connectors are not deformed and damaged.

    NG → REPAIR OR REPLACE FRONT SEAT WIRE RH 

    OK: Go to next step 

  11. REPLACE FRONT SEAT INNER BELT ASSEMBLY RH 
    1. Turn the engine switch off.
    2. Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.
    3. Replace the front seat inner belt RH. Refer to REMOVAL .
    4. Connect the negative (-) terminal cable to the battery.

    NEXT: Go to next step 

  12. PERFORM ZERO POINT CALIBRATION 
    1. Connect the Techstream to the DLC3.
    2. Turn the engine switch on (IG).
    3. Using the Techstream, perform the zero point calibration. Refer to INITIALIZATION .

    NEXT: Go to next step 

  13. PERFORM SENSITIVITY CHECK 
    1. Perform the sensitivity check. Refer to DIAGNOSIS SYSTEM .

    NEXT → END 

  14. CHECK CONNECTOR 
    1. Disconnect the connectors from the occupant classification ECU and the belt tension sensor.
    2. Check that the connectors (on the center airbag sensor side and seat belt tension sensor side) are not damaged.

      OK

      Connectors are not deformed or damaged.

    NG → REPAIR OR REPLACE FRONT SEAT WIRE RH 

    OK: Go to next step 

  15. REPLACE FRONT SEAT OUTER BELT ASSEMBLY RH (SEAT BELT TENSION SENSOR) 
    1. Turn the engine switch off.
    2. Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.
    3. Replace the front seat outer belt RH. Refer to REMOVAL .
    4. Connect the negative (-) terminal cable to the battery.

    NEXT: Go to next step 

  16. PERFORM ZERO POINT CALIBRATION 
    1. Connect the Techstream to the DLC3.
    2. Turn the engine switch on (IG).
    3. Using the Techstream, perform the zero point calibration. Refer to DIAGNOSIS SYSTEM .

    NEXT: Go to next step 

  17. PERFORM SENSITIVITY CHECK 
    1. Perform the sensitivity check. Refer to DIAGNOSIS SYSTEM .

    NEXT → END 

  18. Go to DTC B1797. Refer to  DTC B1797: Calibration Malfunction