OCCUPANT CLASSIFICATION SYSTEM


  1. FUNCTION OF MAIN COMPONENTS


    1. The main components of the occupant classification System have the following functions:

      Component Function
      Occupant Detection ECU Judges whether the front passenger seat is occupied based on signals from 2 occupant classification sensors and front passenger seat belt buckle switch (front seat inner belt assembly RH).
      Occupant Classification Sensor (Front LH or Rear LH) The sensors are strain gauge type sensors that send signals to the occupant detection ECU in accordance with the weight of the occupant.
      Front Passenger Seat Belt Buckle Switch (Front Seat Inner Belt Assembly RH) Detects if the front passenger seat belt is fastened.
      Combination Meter Assembly SRS Warning Light Turns on to alert the driver when the airbag ECU assembly detects a malfunction in the airbag system.
      AIRBAG ON/OFF Indicator Lights

      • Informs the driver whether the occupant detection ECU has put the instrument panel passenger airbag without door assembly, front seat cushion airbag assembly RH and front passenger outer belt assembly RH into an active state or inactive state.

      • If a malfunction occurs in the occupant detection system, the AIRBAG OFF indicator light and SRS warning light come on.

  2. SYSTEM CONTROL


    1. Summary


      1. In the occupant classification system, the occupant detection ECU calculates the weight of the occupant based on signals from the occupant classification sensors.

      2. The occupant detection ECU contains criteria value "A" to judge whether the seat is occupied by a child or is unoccupied in accordance with the signals from the 2 occupant classification sensors and front passenger seat belt buckle switch (front seat inner belt assembly RH), and criteria value "B" to judge whether the occupant is an adult or child (with child seat).

      3. This system recognizes the occupant as a child or child seat if it detects a weight of less than "B", and disables the instrument panel passenger airbag without door assembly and front seat cushion airbag assembly RH.

    2. Unoccupied Judgment


      1. The occupant detection ECU makes an unoccupied judgment when the judgment value is lower than criteria value "A" and the front passenger seat belt buckle switch (front seat inner belt assembly RH) is off.

      2. If the power switch is turned on (IG) in this state, the system performs an initial check, and illuminate the AIRBAG OFF indicator light. Then, the system prohibits the deployment of the instrument panel passenger airbag without door assembly and front seat cushion airbag assembly RH, and does not blink the seat belt warning light.

        A01RGTFE04

    3. Child Seat or Child Judgment


      1. If the judgment value is lower than criteria value "B" and the front passenger seat belt buckle switch (front seat inner belt assembly RH) is ON, the occupant detection ECU judges that a child seat is installed.

      2. If the judgment value is higher than criteria value "A", but lower than criteria value "B", and the front passenger seat belt buckle switch (front seat inner belt assembly RH) is OFF, the occupant detection ECU judges that the seat is being occupied by a child.

      3. When the power switch is turned on (IG) under these conditions, the system performs an initial check and illuminates the AIRBAG OFF indicator light to indicate that the instrument panel passenger airbag without door assembly and front seat cushion airbag assembly RH have been deactivated.

        A01RGODE04

    4. Adult Judgment


      1. After the occupant detection ECU judges that a child seat is installed, the AIRBAG OFF indicator light does not go off unless the front passenger seat belt buckle switch (front seat inner belt assembly RH) is turned OFF.

      2. When the judgment value is higher than criteria value "B", the occupant detection ECU judges that the seat is occupied by an adult.

      3. If the power switch is turned on (IG) in this state, the system performs an initial check and illuminates the AIRBAG ON indicator light, indicating that the instrument panel passenger airbag without door assembly, front seat airbag sub-assembly RH and front seat airbag assembly RH are active.

        A01RGU6E04

    5. After the occupant detection ECU judges that the occupant is an adult, and if the judgment value is determined as criteria value "A" or less according to occupant load movement and the front passenger seat belt buckle switch (front seat inner belt assembly RH) is off, the ECU continues adult judgment for approximately 20 seconds before switching to the unoccupied judgment.

      A01RGV2E22

    6. The front passenger SRS items and indicator lights operate as follows according to the occupant classification:

      Items Occupant Classification
      Adult Child Child Seat Unoccupied Malfunction
      Front Passenger SRS Components Front Airbag ○ X X X X
      Seat Cushion Airbag ○* X X X X
      Side Airbag ○ ○ ○ ○ ○
      Seat Belt Pretensioner ○ ○ ○ ○ ○
      AIRBAG ON/OFF Indicator Lights ON Indicator Light ON OFF OFF OFF OFF
      OFF Indicator Light OFF ON ON ON ON

      ○: Deploys

      X: Does not deploy

      Tech Tips

      *: Cannot be deployed when the front passenger seat belt has been unfastened.

  3. DIAGNOSIS


    1. If the occupant detection ECU detects a malfunction in the occupant classification system, the occupant detection ECU stores the malfunction data in memory as Diagnostic Trouble Codes (DTCs). If the airbag ECU assembly detects a malfunction in the occupant detection ECU, the airbag ECU assembly illuminates the SRS warning light and AIRBAG OFF indicator light.

    2. The occupant detection ECU outputs 5-digit Diagnostic Trouble Codes (DTCs) to the Global TechStream (GTS).

    3. The 5-digit DTCs can be read by connecting the Global TechStream (GTS) to the DLC3. For details, refer to the Repair Manual.