AIRBAG SYSTEM


  1. FUNCTION OF MAIN COMPONENTS


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

      Components Function
      Airbag Sensor Assembly

      • In the event of a frontal collision, the airbag sensor assembly receives the signal from either of the front airbag sensors. The airbag sensor assembly receives the signal via its judgment circuit and also receives another signal from the safing sensor built into the airbag sensor assembly. After receiving signals from the safing sensor and at least one of the front airbag sensors, the airbag sensor assembly determines whether the driver airbag, front passenger airbag, driver knee airbag, front passenger seat cushion airbag, front side airbags, rear No. 1 seat side airbags and curtain shield airbags should be deployed, and the front seat belt pretensioners, rear No. 1 seat belt pretensioners and selectable force limiter*2 should be activated. The airbag sensor assembly also diagnosis system malfunctions.

      • In the event of a side or rear side collision, the airbag sensor assembly receives signals from the door side airbag sensor, rear airbag sensor or side airbag sensor assembly*1. The airbag sensor assembly receives the door side airbag sensor or rear airbag sensor signal via its judgment circuit and also receives another signal from the side airbag sensor assembly*1 or safing sensor built into the airbag sensor assembly. After receiving a signal from at least one of the door side airbag sensors and rear airbag sensors and either of the safing sensors (side airbag sensor assembly*1 or safing sensor built into the airbag sensor assembly), the airbag sensor assembly determines whether the front side airbag, rear No. 1 seat side airbag and curtain shield airbag should be deployed, and the front seat belt pretensioner, rear No. 1 seat belt pretensioner and selectable force limiter*2 should be activated. The airbag sensor assembly also diagnosis system malfunctions.

      • Sends the collision detection signal to the ECM through the Controller Area Network (CAN) to operate fuel pump control.

      • Sends the collision detection signal to the main body ECU (multiplex network body ECU) to operate the collision door lock release function.

      • Sends the collision detection signal to the telematics transceiver (data communication module) for the emergency call of automatic collision notification service.*3

      • Sends the collision detection signal to the hybrid vehicle control ECU assembly to shut down the hybrid system power supply.
      Horn Button Assembly Used as supplements to the seat belts to help reduce impact to the occupants.
      Instrument Panel Passenger Airbag without Door Assembly
      Lower No. 1 Instrument Panel Airbag Assembly
      Front Seat Cushion Airbag Assembly
      Front Seat Airbag Assembly LH/RH
      Rear Seat Airbag Assembly LH/RH
      Curtain Shield Airbag Assembly LH/RH
      Spiral Cable Sub-assembly Transmits ignition signals from the airbag sensor assembly to the driver airbag.
      Front Airbag Sensor LH/RH Based on the deceleration of the vehicle during a frontal collision, distortion is created in the sensor and is converted into an electrical signal.
      Door Side Airbag Sensor LH/RH Detects deformation of the front doors during a side collision using the pressure sensor and sends signals for the airbag sensor assembly to determine if deployment of SRS components is necessary.
      Rear Airbag Sensor LH/RH Based on the deceleration of the vehicle during a rear side collision, distortion is created in the sensor and is converted into an electrical signal.
      Side Airbag Sensor Assembly LH/RH*1 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.
      Front Seat Outer Belt Assembly LH/RH Used to help reduce impact to the occupants.
      Rear No. 1 Seat Outer Belt Assembly LH/RH
      Seat Position Airbag Sensor Detects the slide position of the driver seat.
      Driver Seat Belt Buckle Switch (Front Seat Inner Belt Assembly) Detects if the driver seat belt is fastened.
      Front Passenger Seat Belt Buckle Switch (Front Seat Inner Belt Assembly) Detects if the front passenger seat belt is fastened.
      Occupant Detection ECU*2 Judges whether the front passenger seat is occupied based on signals from the 2 occupant classification sensors and the front passenger seat belt buckle switch.
      Front Occupant Classification Sensor LH*2 The sensors are strain gauge type sensors that send signals to the occupant detection ECU in accordance with the weight of the occupant.
      Rear Occupant Classification Sensor LH*2
      Airbag Cut Off Switch Cylinder Sub-assembly*1 Suspends the instrument panel passenger airbag without door assembly, front seat cushion airbag assembly RH and front seat airbag assembly RH operations in the event of a frontal collision.
      Hybrid Vehicle Control ECU Assembly Receives the collision detection signal from the airbag sensor assembly during a collision and shuts down the hybrid system power supply by turning the System Main Relays (SMRs) off, in order to ensure safety.
      ECM Receives the collision detection signal from the airbag sensor assembly and stops to the fuel pump.
      Main Body ECU (Multiplex Network Body ECU) Receives the collision detection signal from the airbag sensor assembly and operates the collision door lock release function.
      Combination Meter Assembly SRS Warning Light Turns on to alert the driver when the airbag sensor assembly detects a malfunction in the airbag system.
      Multi-information Display Displays a warning message to inform the driver of a malfunction in the airbag system.
      Master Warning Light Turns on to alert the driver when the airbag sensor assembly detects a malfunction in the airbag system.
      Buzzer Sounds to warn the driver of a malfunction in the airbag system.
      Radio Receiver Assembly*1, *2 AIRBAG OFF Indicator Light

      • Inform the driver whether the occupant detection ECU puts the instrument panel passenger airbag without door assembly, front seat cushion airbag assembly RH, front seat airbag assembly RH and front seat outer belt assembly RH into an active state or inactive state.*2

      • Inform the occupants of the airbag cut off switch cylinder sub-assembly status.*1
      AIRBAG ON Indicator Light
      Telematics Transceiver (Data Communication Module)*3 Receives the collision detection signal from the airbag sensor assembly, and automatically makes the emergency call of automatic collision notification service.
      Network Gateway ECU Relays the signal between the CAN communication.

      *1: Models with airbag cut off switch cylinder

      *2: Destination package for South Korea

      *3: Models with telematics transceiver

  2. SYSTEM CONTROL


    1. Airbag for Frontal Collision


      1. There are 10 airbags which deploy in the event of a frontal collision: the horn button assembly, instrument panel passenger airbag without door assembly, lower No. 1 instrument panel airbag assembly, front seat cushion airbag assembly, front seat airbag assemblies, rear seat airbag assemblies and curtain shield airbag assemblies. These airbags deploy simultaneously. The horn button assembly and instrument panel passenger airbag without door assembly use dual-stage control. In addition, each front pretensioner contained in a front seat outer belt assembly, each rear No. 1 seat pretensioner contained in a rear No. 1 seat outer belt assembly and the selectable force limiter contained in the front seat outer belt assembly RH* are also activated.

        *: Destination package for South Korea

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

        Airbag Information Source
        Driver Extent of Impact

        • Front Airbag Sensor LH or RH

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

        • Front Airbag Sensor LH or RH

        • Airbag Sensor Assembly
        Occupant Classification*1, *2

        • 2 Occupant Classification Sensors*1

          (Connected to the airbag sensor assembly through the occupant detection ECU.)

        • Airbag Cut Off Switch Cylinder Sub-assembly*2
        Seat Belt Condition

        Front Passenger Seat Belt Buckle Switch (Front Seat Inner Belt Assembly RH) (Non-contact Type)

        (Connected to the airbag sensor assembly through the occupant detection ECU.)

        *1: Destination package for South Korea

        *2: Models with airbag cut off switch cylinder

      3. For a frontal collision, if a front airbag sensor detects an impact, it informs the airbag sensor assembly. The airbag sensor assembly causes the horn button assembly, instrument panel passenger airbag without door assembly, lower No. 1 instrument panel airbag assembly, front seat cushion airbag assembly, front seat airbag assemblies, rear seat airbag assemblies and curtain shield airbag assemblies to deploy. Additionally, the airbag sensor assembly activates the selectable force limiter for the front passenger* and the seat belt pretensioners for the driver, front passenger and rear No. 1 seat outer passengers.

        *: Destination package for South Korea

        B0055I1E01
        B0055G1E02

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

      5. Depending on the situation, the airbag sensor assembly sends a deployment signal to each airbag, each pretensioner and the selectable force limiter* based on the information from each sensor.

        *: Destination package for South Korea

      6. Frontal collision signals are produced based on the information from the airbag sensor assembly and front airbag sensors. Frontal collision signals are used to deploy all the airbags and activate all the pretensioners and the selectable force limiter* as indicated in the table below.

        *: Destination package for South Korea

        Figure 1. Frontal Collision

        B0055NXE02

    2. Airbag for Side/Rear Side Collision


      1. There are 3 airbags which deploy in the event of a severe side collision: the front seat airbag assembly, rear seat airbag assembly and curtain shield airbag assembly. These airbags deploy simultaneously. Additionally, at the same time, the front seat belt pretensioners, rear No. 1 seat belt pretensioners and selectable force limiter* are also activated.

        *: Destination package for South Korea on the collision from right side.

      2. For a side collision, if the door side airbag sensor and side airbag sensor assembly*1 detect an impact, they inform the airbag sensor assembly, and the airbag sensor assembly causes the front seat airbag assembly, rear seat airbag assembly and curtain shield airbag assembly to deploy simultaneously, and activates the front seat belt pretensioner, rear No. 1 seat belt pretensioner and selectable force limiter*2.

        *1: Models with airbag cut off switch cylinder

        *2: Destination package for South Korea on the collision from right side.

        B0055D1E01

      3. The front seat airbag assembly, rear seat airbag assembly and curtain shield airbag assembly are deployed and the front pretensioner in the front seat outer belt assembly, the rear No. 1 seat pretensioner in the rear No. 1 seat outer belt assembly and the selectable force limiter in the front seat outer belt assembly RH*1 are activated based on signals from the door side airbag sensor, side airbag sensor assembly*2 and airbag sensor assembly.

        *1: Destination package for South Korea on the collision from right side.

        *2: Models with airbag cut off switch cylinder

        Figure 2. Side Collision

        B0055H2E01

      4. For a rear side collision, if the rear airbag sensor and side airbag sensor assembly* detect an impact, they inform the airbag sensor assembly, and the airbag sensor assembly causes the rear seat airbag assembly and curtain shield airbag assembly to deploy simultaneously, and activates the rear No. 1 seat belt pretensioner.

        *: Models with airbag cut off switch cylinder

        B0055F6E01

      5. The rear seat airbag assembly and curtain shield airbag assembly are deployed and rear No. 1 seat pretensioner in the rear No. 1 seat outer belt assembly is activated based on signals from the rear airbag sensor, side airbag sensor assembly* and airbag sensor assembly.

        *: Models with airbag cut off switch cylinder

        Figure 3. Rear Side Collision

        B0055J2E01

    3. Airbag for Roll Over (Destination Package for South Korea)


      1. If the vehicle is tilted and rolls over, the airbag sensor assembly activates the front seat belt pretensioners, rear No. 1 seat belt pretensioners and selectable force limiter and deploys the curtain shield airbags based on signals that show the vehicle's roll angle and rotation speed.

        B0055NME01

      2. If the vehicle rolls over in a side collision, the airbag sensor assembly causes the front seat airbag assembly, rear seat airbag assembly and curtain shield airbag assembly to deploy and activates the front seat belt pretensioner, rear No. 1 seat belt pretensioner and selectable force limiter*1 based on signals from the door side airbag sensor and rear airbag sensor. Meanwhile, it deploys the curtain shield airbag on the opposite side of the collision and activates the front seat belt pretensioner, rear No. 1 seat belt pretensioner and selectable force limiter*2 on the opposite side of the collision, based on lateral deceleration and rotation speed signals.

        *1: On the collision from right side.

        *2: On the collision from left side.

        B0055F3E01
        B0055L1E01

    4. Primary Check Illumination Control


      1. After the power switch is turned on (IG), the airbag sensor 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 airbags is prohibited and a diagnosis of the airbag sensor 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 sensor assembly operates the AIRBAG ON/OFF indicator lights as shown below to check for an open in the indicator light circuits.

        B0055N6E06

  3. DIAGNOSIS


    1. If the airbag sensor assembly detects a malfunction in the airbag system, the airbag sensor assembly stores the malfunction data in memory as Diagnostic Trouble Codes (DTCs) in addition to illuminates the SRS warning light and master warning light, displays the warning message on the multi-information display and sounds the buzzer to alert the driver of the malfunction.

    2. The airbag sensor 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 sensor 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 sensor assembly with a new one.