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Home >> Infiniti >> 2009 >> M45 Base >> Repair and Diagnosis >> External Pages >> Different car >> Section 154 (Supplemental Restraint System) >> Occupant Classification System >> DTC B1785: Front Occupant Classification Sensor LH Collision Detection >> Inspection Procedure
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Inspection Procedure

WARNING: This page is about a different car, the 2008 Toyota Tundra. However, it is still accessible from the selected car via links, so may be relevant.
NOTE: After the ignition switch is turned OFF, the navigation system requires approximately 90 seconds to record various types of memory and settings. As a result, after turning the ignition switch OFF, wait 90 seconds or more before disconnecting the cable from the negative (-) battery terminal.
  1. CHECK FOR DTC 
    1. Turn the ignition switch ON, and wait for at least 60 seconds.
    2. Clear any DTCs stored in the center airbag sensor (see DTC CHECK/CLEAR  ).
    3. Turn the ignition switch OFF.
    4. Turn the ignition switch ON, and wait for at least 60 seconds.
    5. Using the Techstream, check for DTCs of the occupant classification ECU (see DTC CHECK/CLEAR  ).

      OK: DTC B1785 is not output. 

      HINT:

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

    NG: Go to step   2 

    OK: USE SIMULATION METHOD TO CHECK  (See DIAGNOSIS SYSTEM  )

  2. PERFORM ZERO POINT CALIBRATION 
    1. Connect the Techstream to the DLC3.
    2. Turn the ignition switch ON, and wait for at least 60 seconds.
    3. Using the Techstream, perform the zero point calibration (see INITIALIZATION  ).

    NG: Go to step   5 

    OK: Go to next step 

  3. PERFORM SENSITIVITY CHECK 
    1. Using the Techstream, perform the sensitivity check (see INITIALIZATION  ).

      Standard range: 

      27 to 33 kg (59.5 to 72.8 lb) 

    NG: Go to step   5 

    OK: Go to next step 

  4. CHECK FOR DTC 
    1. Turn the ignition switch ON, and wait for at least 60 seconds.
    2. Clear any DTCs stored in the center airbag sensor (see DTC CHECK/CLEAR  ).
    3. Turn the ignition switch OFF.
    4. Turn the ignition switch ON, and wait for at least 60 seconds.
    5. Using the Techstream, check for DTCs of the occupant classification ECU (see DTC CHECK/CLEAR  ).

      OK: DTC B1785 is not output. 

      HINT:

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

    NG: Go to step   5 

    OK: END 

  5. REPLACE FRONT SEAT FRAME WITH ADJUSTER ASSEMBLY RH 
    1. Turn the ignition switch OFF.
    2. Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.
    3. Replace the front seat frame with adjuster RH (see FRONT POWER SEAT MOTOR ASSEMBLY (FOR POWER SEAT) ).

      HINT:

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

  6. PERFORM ZERO POINT CALIBRATION 
    1. Connect the negative (-) terminal cable to the battery, and wait for at least 2 seconds.
    2. Connect the Techstream to the DLC3.
    3. Turn the ignition switch ON, and wait for at least 60 seconds.
    4. Using the Techstream, perform the zero point calibration (see INITIALIZATION  ).

    NG: Go to step   9 

    OK: Go to next step 

  7. PERFORM SENSITIVITY CHECK 
    1. Using the Techstream, perform the sensitivity check (see INITIALIZATION  ).

      Standard range: 

      27 to 33 kg (59.5 to 72.8 lb) 

    NG: Go to step   9 

    OK: Go to next step 

  8. CHECK FOR DTC 
    1. Connect the connectors to the occupant classification ECU and the front occupant detection sensor LH.
    2. Turn the ignition switch ON, and wait for at least 60 seconds.
    3. Clear any DTCs stored in the memory (see DTC CHECK/CLEAR  ).

      HINT:

      • First clear DTCs stored in the occupant classification ECU and then in the center airbag sensor.
      • Use the Techstream to clear the DTCs of the occupant classification ECU, otherwise the DTCs cannot be cleared.
    4. Turn the ignition switch OFF.
    5. Turn the ignition switch ON, and wait for at least 60 seconds.
    6. Using the Techstream, check for DTCs of the occupant classification ECU (see DTC CHECK/CLEAR  ).

      OK: DTC B1785 is not output. 

      HINT:

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

    NG: Go to step   9 

    OK: END 

  9. REPLACE OCCUPANT CLASSIFICATION ECU 
    1. Turn the ignition switch OFF.
    2. Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.
    3. Replace the occupant classification ECU.

      HINT:

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

  10. PERFORM ZERO POINT CALIBRATION 
    1. Connect the negative (-) terminal cable to the battery, and wait for at least 2 seconds.
    2. Connect the Techstream to the DLC3.
    3. Turn the ignition switch ON, and wait for at least 60 seconds.
    4. Using the Techstream, perform the zero point calibration (see INITIALIZATION  ).
  11. PERFORM SENSITIVITY CHECK 
    1. Using the Techstream, perform the sensitivity check (see INITIALIZATION  ).

      Standard range: 

      27 to 33 kg (59.5 to 72.8 lb) 

    NEXT: END 

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