AIRBAG SYSTEM


  1. FUNCTION OF MAIN COMPONENTS


    1. The main components in the airbag system have the following functions:

      Components Function
      Driver Airbag (Horn Button Assembly) Used as supplements to the seat belts to help reduce impact to the occupants.
      Front Passenger Airbag (Instrument Panel Passenger Airbag without Door Assembly)
      Driver Knee Airbag (Lower No. 1 Instrument Panel Airbag Assembly)
      Front Passenger Knee Airbag (Lower No. 2 Instrument Panel Airbag Assembly)
      Driver Side Airbag (Front Seat Airbag Assembly LH)
      Front Passenger Side Airbag (Front Seat Airbag Assembly RH)
      Curtain Shield Airbag Assembly LH
      Curtain Shield Airbag Assembly RH

      Front Seat Outer Belt Assembly LH


      • Seat Belt Pretensioner

      		 Used to help reduce impact to the occupants.

      Front Seat Outer Belt Assembly RH


      • Seat Belt Pretensioner

      Rear No. 1 Seat Outer Belt Assembly LH


      • Seat Belt Pretensioner

      Rear No. 1 Seat Outer Belt Assembly RH


      • Seat Belt Pretensioner
      Spiral Cable with Sensor Sub-assembly Transmits ignition signals from the airbag ECU assembly to the SRS driver airbag.
      Seat Position Airbag Sensor Detects the slide position of the driver seat.
      Front Airbag Sensor LH Based on the deceleration of the vehicle during a frontal collision, distortion is created in the sensor and is converted into an electrical signal.
      Front Airbag Sensor RH
      Door Side Airbag Sensor LH Detects deformation of the front doors during a side collision using the pressure sensor and sends signals for the airbag ECU assembly to determine if deployment of SRS components is necessary.
      Door Side Airbag Sensor RH
      Side Airbag Sensor Assembly LH Based on the deceleration of the vehicle during a side or rear side collision, distortion is created in the sensor and is converted into an electrical signal.
      Side Airbag Sensor Assembly RH
      Rear Airbag Sensor LH
      Rear Airbag Sensor RH
      Yawrate Sensor Sends yawrate sensor signals to the airbag ECU assembly via CAN communication.
      Steering Sensor Sends steering angle signals to the airbag ECU assembly via CAN communication.
      Airbag Cut Off Switch Cylinder Sub-assembly* Suspends the SRS front passenger airbag operation.
      Driver Seat Belt Buckle Switch (Front Seat Inner Belt Assembly LH) Detects if the driver seat belt is fastened.
      Front Passenger Seat Belt Buckle Switch (Front Seat Inner Belt Assembly RH) Detects if the front passenger seat belt is fastened.
      Airbag ECU Assembly

      • In the event of a frontal collision, the airbag ECU assembly receives signals from either of the front airbag sensors. The airbag ECU assembly receives the signal via its judgment circuit and also receives another signal from the safing sensor built into the airbag ECU assembly. After receiving a signal from at least one of the front airbag sensors and the safing sensor, the airbag ECU assembly determines whether the SRS driver airbag, SRS front passenger airbag, SRS driver knee airbag, SRS front passenger knee airbag, SRS curtain shield airbag assemblies and front and rear seat belt pretensioners should be deployed. The airbag ECU assembly also diagnoses system malfunctions.

      • In the event of a side or rear side collision, the airbag ECU assembly receives signals from the door side airbag sensor, side airbag sensor assembly or rear airbag sensor. The airbag ECU assembly receives the signal via its judgment circuit and also receives another signal from the safing sensor built into the airbag ECU assembly. After receiving a signal from at least one of the side sensors and the safing sensor, the airbag ECU assembly determines whether the SRS driver and front passenger side airbags, SRS curtain shield airbag assemblies and seat belt pretensioners should be deployed. The airbag ECU assembly also diagnoses system malfunctions.
      Pedestrian Detection ECU Assembly Sends the operation status of the pop up hood system to the airbag ECU assembly via CAN communication.
      Hybrid Vehicle Control ECU Assembly Sends shift position signals and the operation status of the hybrid control system to the airbag ECU assembly via CAN communication.
      ECM Sends engine speed signals and the operation status of the engine control system to the airbag ECU assembly via CAN communication.
      Skid Control ECU Assembly Sends vehicle speed signals, brake pedal operation signals and the operation status of the brake control system to the airbag ECU assembly via CAN communication.
      Combination Meter Assembly SRS Warning Light Turns on to alert the driver when the airbag ECU assembly detects a malfunction in the SRS airbag system.
      Multi-information Display Displays a warning message to inform the driver of a malfunction in the SRS airbag system.
      Master Warning Light Turns on to alert the driver when the airbag ECU assembly detects a malfunction in the SRS airbag system.
      Buzzer Sounds to warn the driver of a malfunction in the SRS airbag system.
      Telltale Light Assembly* AIRBAG ON Indicator Light Informs the occupants of the airbag cut off switch cylinder status.
      AIRBAG OFF Indicator Light
      Central Gateway ECU (Network Gateway ECU) Relays the signal between the CAN communication lines.
      DLC3 The Global TechStream (GTS) can be connected to read the Diagnostic Trouble Codes (DTCs) of malfunctions.

      *: Models with airbag cut off switch cylinder

  2. OPERATING CONDITION


    1. Frontal Collision


      1. Deceleration sensors used for the SRS airbag system are installed on various parts on the vehicle and calculate the deceleration (or acceleration) rate of each part during a collision.

      2. Depending on the situation, the airbag ECU assembly sends a deployment signal to each SRS airbag based on the information from each sensor.

      3. Frontal collision signals are produced based on the information from the airbag ECU assembly and front airbag sensors. Frontal collision signals are used to deploy the SRS airbags and activate the seat belt pretensioners as indicated in the table below.

      4. If the severity of the collision is particularly high, the SRS curtain shield airbag assemblies LH and RH are deployed.

        A004C2LE01

    2. Side Collision


      1. The SRS side airbag and SRS curtain shield airbag assembly on the side of the collision are deployed and the front and rear seat belt pretensioners on the side of the collision are activated based on signals from the door side airbag sensor, side airbag sensor assembly and airbag ECU assembly.

      2. If the severity of the collision is particularly high, the SRS curtain shield airbag assembly on the side opposite the collision is deployed and the front and rear seat belt pretensioners on the side opposite the collision are activated.

        A004CLEE01

    3. Rear Side Collision


      1. The SRS curtain shield airbag assembly on the side of the collision is deployed and the rear seat belt pretensioner on the side of the collision is activated based on signals from the rear airbag sensor, side airbag sensor assembly and airbag ECU assembly.

      2. If the severity of the collision is particularly high, SRS curtain shield airbag assembly on the side opposite the collision is deployed and rear seat belt pretensioner on the side opposite the collision is activated.

        A004CQYE01

  3. SYSTEM CONTROL


    1. Frontal Collision


      1. There are 4 SRS airbags which deploy in the event of a frontal collision: the SRS driver airbag, SRS front passenger airbag, SRS driver knee airbag and SRS front passenger knee airbag. These SRS airbags deploy simultaneously. The SRS driver airbag and SRS front passenger airbag use dual-stage control. In addition, the seat belt pretensioners contained in the front seat outer belt assemblies LH and RH and the rear No. 1 seat outer belt assemblies LH and RH are also activated.

      2. The airbag ECU assembly detects the information in the table below from various sources in order to activate the dual-stage control.

      3. For a frontal collision, if a front airbag sensor detects an impact, it informs the airbag ECU assembly. The airbag ECU assembly causes the SRS driver airbag, SRS front passenger airbag, SRS driver knee airbag and SRS front passenger knee airbag to deploy. Additionally, the airbag ECU assembly activates the front and rear seat belt pretensioners.

      4. If the severity of the collision is particularly high, the SRS curtain shield airbag assemblies LH and RH are deployed.

        Airbag Information Source
        Driver Extent of Impact

        • Front Airbag Sensor LH or RH

        • Airbag ECU Assembly
        Driver Seat Position Seat Position Airbag Sensor
        Seat Belt Condition Driver Seat Belt Buckle Switch (Non-contact Type)
        Front Passenger Extent of Impact

        • Front Airbag Sensor LH or RH

        • Airbag ECU Assembly
        Airbag Cut Off Switch Cylinder Status Airbag Cut Off Switch Cylinder Sub-assembly
        Seat Belt Condition Front Passenger Seat Belt Buckle Switch (Non-contact Type)
        A004CKWE01

    2. Side Collision


      1. There are 2 SRS airbags which deploy in the event of a side collision: the SRS side airbag and SRS curtain shield airbag assembly on the side of the collision. These SRS airbags deploy simultaneously. Additionally, at the same time, the front and rear seat belt pretensioners on the side of the collision are also activated.

      2. For a side collision, if the door side airbag sensor and side airbag sensor assembly detects an impact, it informs the airbag ECU assembly. The airbag ECU assembly causes the SRS side airbag and SRS curtain shield airbag assembly on the side of the collision to deploy simultaneously, and activates the front and rear seat belt pretensioners on the side of the collision.

      3. If the severity of the collision is particularly high, the SRS curtain shield airbag assembly on the side opposite the collision is deployed and the front and rear seat belt pretensioners on the side opposite the collision are activated.

        A004CRWE01

    3. Rear Side Collision


      1. The SRS curtain shield airbag assembly on the side of the collision deploys in the event of a rear side collision. Additionally, at the same time, the rear seat belt pretensioner on the side of the collision is also activated.

      2. For a rear side collision, if the rear airbag sensor detects an impact, it informs the airbag ECU assembly and the airbag ECU assembly causes the SRS curtain shield airbag assembly on the side of the collision to deploy simultaneously, and activates the rear seat belt pretensioner on the side of the collision.

      3. If the severity of the collision is particularly high, the SRS curtain shield airbag assembly on the side opposite the collision is deployed and the rear seat belt pretensioner on the side opposite the collision is activated.

        A004CTXE01

    4. Primary Check Illumination Control


      1. After the power switch is turned on (IG), the airbag ECU assembly illuminates the SRS warning light in the combination meter assembly for approximately 6 seconds and conducts the primary check. During the primary check, the ignition of SRS airbags is prohibited and a diagnosis of the airbag ECU assembly is performed. If a malfunction is detected during the primary check, the SRS warning light will remain on even after 6 seconds have elapsed.

      2. After the power switch is turned on (IG), the airbag ECU assembly operates the front passenger airbag ON/OFF indicator lights as shown below to check for an open in the indicator light circuits.

        A004CH1E03

  4. DIAGNOSIS


    1. If the airbag ECU assembly detects a malfunction in the SRS airbag system, the airbag ECU assembly stores the malfunction data in memory in addition to illuminating the SRS warning light.

    2. The airbag ECU assembly outputs malfunction data and 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.

    4. If the SRS airbags deploy, the airbag ECU assembly will turn on the SRS warning light. However, unlike an ordinary malfunction, a DTC will not be stored. The SRS warning light cannot be manually turned off. It is necessary to replace the airbag ECU assembly with a new one.