AIRBAG SYSTEM DETAILS


  1. FUNCTION OF MAIN COMPONENTS


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

      Components Outline
      Center Airbag Sensor Assembly

      • The center airbag sensor assembly receives signals from the deceleration sensor and safing sensor built into the center airbag sensor assembly and one of the front airbag sensors, determines whether the horn button assembly (driver side squib), instrument panel passenger without door airbag assembly, lower No. 1 and lower No. 2 instrument panel airbag assembly, front seat outer belt assembly (pretensioner squib) and rear seat 3 point type outer belt assembly (pretensioner squib) should be activated, and diagnoses system malfunctions.

      • The center airbag sensor assembly receives signals from the deceleration sensor, the safing sensor built into the center airbag sensor assembly, the side airbag sensor assembly, rear airbag sensor and door side airbag sensor, determines whether the front and rear*1 seat airbag assembly, the curtain shield airbag assembly, front seat outer belt assembly (pretensioner squib) and rear seat 3 point type outer belt assembly (pretensioner squib) should be activated, and diagnosis system malfunctions.

      • The center airbag sensor assembly sends the airbag deployment signal to the main body ECU to operate the collision door lock release function.
      Horn Button Assembly (Driver Side Squib) These consist of an inflator, a bag, and so on. The inflator deploys gas in accordance with an expansion signal from the center airbag sensor assembly and deploys the bag.
      Instrument panel Passenger without Door Airbag Assembly
      Lower No. 1 Instrument Panel Airbag Assembly
      Lower No. 2 Instrument Panel Airbag Assembly
      Front Seat Airbag Assembly
      Rear Seat Airbag Assembly*1
      Curtain Shield Airbag Assembly
      Front Airbag Sensor The front airbag sensor uses an electrical type deceleration sensor. Based on the deceleration of the vehicle during a frontal collision, a distortion is created in the sensor and converted into an electrical signal. Accordingly, the extent of the initial collision can be detected in detail.
      Side Airbag Sensor Assembly A deceleration sensor is enclosed in the side airbag sensor assembly and rear airbag sensor. Based on the deceleration of the vehicle during a side or rear side collision, a distortion is created in the sensor and converted into an electrical signal.
      Rear Airbag Sensor
      Airbag Cut Off Switch Cylinder*2 The deployment of the instrument panel passenger without door airbag assembly and the front seat airbag assembly at the time of collision can be turned on and off as required.
      Occupant Detection Sensor The resistance values of this sensor, which vary in accordance with the distortion that acts on the brackets, are output to the combination meter assembly.
      Combination Meter Assembly SRS Warning Light The SRS warning light turns on to alert the driver when the center airbag sensor assembly detects a malfunction in the airbag system.
      Multi-information Display The multi-information display alerts the driver when the center airbag sensor assembly detects a malfunction in the airbag system.

      • *1: Models with SRS rear side airbag

      • *2: Models with airbag cut off switch cylinder

  2. OPERATING CONDITION


    1. If the impact of a collision is greater than the specified value, the SRS is activated automatically. The center airbag sensor assembly includes the safing sensor and deceleration sensor. The safing sensor is designed to turn on at a lower deceleration rate than the deceleration sensor.


      1. In case of a frontal collision, the center airbag sensor assembly determines whether airbag deployment or pretensioner activation is necessary based on signals from the deceleration sensor and the front airbag sensor. If the safing sensor turns on simultaneously, current flows to the squibs to deploy the SRS components as shown in the illustration below. However, a deployment ignition signal may be output with the deceleration sensor on signal even without a signal from the front airbag sensor.

        A01FPJIE01

      2. In case of a side collision, the center airbag sensor assembly determines whether airbag deployment is necessary based on signals from the side airbag sensor assembly. If the safing sensor turns on simultaneously with the side airbag sensor assembly, current flows to the squibs to deploy the SRS as shown in the illustration below:

        A01FPR8E01

      3. In case of a rear side collision, the center airbag sensor assembly determines whether airbag deployment is necessary based on signals from the rear airbag sensor. If the safing sensor turns on simultaneously with the rear airbag sensor, current flows to the squib to deploy the SRS as shown in the illustration below:

        A01FPSOE02

  3. FUNCTION


    1. Airbag Cut Off Switch Cylinder


      1. A cylinder to disable the deployment of the instrument panel passenger without door airbag assembly and the front seat airbag assembly has been provided. This cylinder can be used if the deployment of those airbags is dangerous, such as when the passenger is wearing a Child Restraint System (CRS) seat belt.

      2. This cylinder is located on the side surface of the front passenger side of the instrument panel. It is switched on or off using a mechanical key. When the airbag cut off switch cylinder is off, the passenger airbag off indicator light will illuminate. At this time, the instrument panel passenger without door airbag assembly and the front seat airbag assembly RH will be disabled regardless of the collision conditions.

        A01FPF7E01
        Text in Illustration
        *1

        - AIRBAG ON Indicator Light

        - AIRBAG OFF Indicator Light

        		 *2 Airbag Cut Off Switch Cylinder
        *3 Mechanical Key - -

  4. CONSTRUCTION


    1. Horn Button Assembly


      1. The inflator and bag are built into the horn button assembly.

        A01FPONE01
        Text in Illustration
        *1 Bag *2 Inflator

    2. Instrument Panel Passenger without Door Airbag Assembly


      1. The instrument panel passenger without door airbag assembly is located in the upper section of the instrument panel of the front passenger seat.

      2. The instrument panel passenger without door airbag assembly consists of an inflator and a bag.

        A01FP2OE01
        Text in Illustration
        *1 Bag *2 Inflator

    3. Lower No. 1 and No. 2 Instrument Panel Airbag Assemblies


      1. The lower No. 1 and lower No. 2 instrument panel airbag assemblies consist of an airbag door, an inflator, and a bag.

        A01FPHNE01
        Text in Illustration
        *1 Bag *2 Inflator
        *3 Airbag Door *4 Lower No. 1 Instrument Panel Airbag Assembly
        *5 Lower No. 2 Instrument Panel Airbag Assembly - -

    4. Front Seat Airbag Assembly


      1. Front seat airbag assemblies are installed in the seat backs of the driver seat and the front passenger seat. Each front seat airbag assembly is a one-piece design, consisting of an inflator and a bag.

        A01FP6GE01
        Text in Illustration
        *1 Bag *2 Inflator
        *a A - A Cross Section - -

    5. Rear Seat Airbag Assembly


      1. Rear seat airbag assemblies are installed in the seat backs of the rear passenger seat. Each rear seat airbag assembly is a one-piece design, consisting of an inflator and a bag.

        A01FPTEE01
        Text in Illustration
        *1 Inflator *2 Bag
        *a A - A Cross Section - -

    6. Curtain Shield Airbag Assembly


      1. Curtain shield airbag assemblies are installed in the area close to the sides of the headliner. Each curtain shield airbag assembly is a one-piece design, consisting of an inflator and a bag.

        A01FPVKE01
        Text in Illustration
        *1 Inflator *2 Bag
        *a A - A Cross Section - -

  5. SYSTEM CONTROL


    1. Airbag for Frontal Collision


      1. There are 3 types of airbags for frontal collisions: horn button assembly, instrument panel passenger without door airbag assembly, lower No. 1 and lower No. 2 instrument panel airbag assemblies. These airbags deploy simultaneously. Meanwhile, the center airbag sensor assembly activates the seat belt pretensioners for the driver, front passenger and rear seat outer passengers.

        A01FPREE01

    2. Airbag for Side/Rear Side Collision


      1. The airbag for side collisions contains 2 types of airbags: front seat airbag assembly and curtain shield airbag assembly. These airbags deploy simultaneously. The airbag for rear side collisions contains only the rear seat airbag assembly* and curtain shield airbag assembly.


        • With the airbag for side collisions, if the side airbag sensor assembly detects an impact, it informs the center airbag sensor assembly, which causes the front seat airbag assembly, rear seat airbag assembly* and curtain shield airbag assembly to be deployed simultaneously. Meanwhile, the center airbag sensor assembly activates the seat belt pretensioners for the driver, front passenger and rear seat outer passengers.

        • With the airbag for rear side collisions, if the rear airbag sensor detects an impact, it informs the center airbag sensor assembly, which causes the rear seat airbag assembly* and curtain shield airbag assembly to be deployed.


          • *: Models with SRS rear side airbag

        A01FPP8E01
        A01FP5NE02

  6. DIAGNOSIS


    1. Summary


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


        • The center airbag sensor assembly outputs the malfunction data as 5-digit Diagnostic Trouble Codes (DTCs) to a Global TechStream (GTS) or the SRS warning light.

        A01FPM6E01

    2. SRS Airbag System DTCs


      1. The 5-digit DTCs can be read after connecting a Global TechStream (GTS) to the DLC3.

      2. If the SRS airbag deploys, the center airbag sensor assembly will turn on the SRS warning light. However, in contrast to the ordinary diagnosis function, a DTC will not be stored. The SRS warning light cannot be turned off. It is necessary to replace the center airbag sensor assembly with a new one.