AIRBAG SYSTEM > DETAILS

The main components have the following functions:

Component		Function
Airbag Sensor Assembly		The airbag sensor assembly receives signals from one of the front airbag sensors via its judgment circuit and from the safing sensor built into the airbag sensor assembly. After receiving these signals, it determines whether the driver airbag, front passenger airbag, driver knee airbag, front passenger knee airbag, curtain shield airbags and front seat belt pretensioners should be activated. It also diagnoses system malfunctions. The airbag sensor assembly receives signals from either the side airbag sensor or No. 2 side airbag sensor via its judgment circuit and from the safing sensor built into the airbag sensor assembly. After receiving these signals, it determines whether the front seat side airbag, curtain shield airbag and front seat belt pretensioner should be activated. It also diagnoses system malfunctions.
Horn Button Assembly	Driver Airbag	The airbags are used as supplements to the seat belts to help reduce impact to the occupants.
Instrument Panel Passenger Airbag Assembly	Front Passenger Airbag
Instrument Panel Airbag Assembly Lower No. 1/No. 2	Driver Knee Airbag/Front Passenger Knee Airbag
Front Seat Airbag Assembly LH/RH	Front Seat Side Airbag LH/RH
Curtain Shield Airbag Assembly LH/RH	Curtain Shield Airbag LH/RH
Front Airbag Sensor LH/RH		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 LH/RH		Based on the deceleration of the vehicle during a side or side rear collision, a distortion is created in the sensor and converted into an electrical signal.
No. 2 Side Airbag Sensor LH/RH
Seat Position Airbag Sensor		The seat position sensor detects the slide position of the driver seat.
Front Seat Outer Belt Assembly	Driver and Front Passenger	The front seat outer belt assemblies are used as supplements to help reduce impact to the occupants.
Front Seat Inner Belt Assembly	Driver Seat Belt Buckle Switch	The driver seat belt buckle switch detects if the driver seat belt is fastened.
	Front Passenger Seat Belt Buckle Switch	The front passenger seat belt buckle switch detects if the front passenger seat belt is fastened.
Power Management Control ECU		The power management control ECU receives an airbag deployment signal from the airbag sensor during a frontal collision or side collision. The power management control ECU will shut down the hybrid system power supply by turning the System Main Relays (SMRs) off, in order to ensure safety.
Combination Meter Assembly	SRS Warning Light	The SRS warning light turns on to alert the driver when the airbag sensor assembly detects a malfunction in the airbag system.

Ignition Condition

1. 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.
   

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





3. 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 the airbags except the side airbags.
   

   
   
   
   





4. The front seat airbag assemblies are deployed and the front seat belt pretensioners are activated based on signals from the side airbag sensors and airbag sensor assembly.
   

   
   
   
   





5. The curtain shield airbag assemblies are deployed based on signals from the side airbag sensors or No. 2 side airbag sensors and the airbag sensor assembly.
   

   
   
   
   

Airbag for Frontal Collision

1. There are 6 airbags which deploy in the event of a frontal collision: the horn button assembly, instrument panel passenger airbag assembly, instrument panel airbag assembly lower No. 1 instrument panel airbag assembly lower No. 2 and curtain shield airbag assemblies. These airbags deploy simultaneously. The horn button assembly and instrument panel passenger airbag assembly use dual-stage control.
   

2. The airbag sensor assembly detects the information indicated 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 sensor assembly. The airbag sensor assembly causes the horn button assembly, instrument panel passenger airbag assembly, instrument panel airbag assembly lower No. 1, instrument panel airbag assembly lower No. 2 and curtain shield airbag assemblies to deploy. Meanwhile, the airbag sensor assembly activates the seat belt pretensioners for the driver and front passenger.
   
   

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

   
   
   
   

Airbag for Side/Side Rear Collision

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





2. For a side collision, if the side airbag sensor or No. 2 side airbag sensor detects an impact, it informs the airbag sensor assembly, and the airbag sensor assembly causes the front seat airbag assembly and curtain shield airbag assembly to deploy simultaneously, and activates the front seat outer belt assembly.
   

   
   
   
   





3. For a side rear collision, if the No. 2 side airbag sensor detects an impact, it informs the airbag sensor assembly via the side airbag sensor, and the airbag sensor assembly causes the curtain shield airbag assembly to be deployed.
   

   
   
   
   

Airbag Cut Off Switch Cylinder Sub-assembly

1. The airbag cut off switch can be used if the deployment of the instrument panel passenger airbag assembly and instrument panel airbag assembly lower No. 2 is undesirable.
   

2. The ON/OFF switch can be operated by the mechanical key, which is supplied with the key. Once the airbag cut off switch is turned to OFF, the instrument panel passenger airbag assembly and instrument panel airbag assembly lower No. 2 will be disabled, regardless of any collision that occurs.
   





3. If the instrument panel passenger airbag assembly and instrument panel airbag assembly lower No. 2 have been disabled, the AIRBAG OFF indicator light in the passenger indicator illuminates to inform the occupant.
   

   
   
   
   

4. The table below shows whether the airbags for the passenger are enabled or disabled, and the AIRBAG OFF indicator on or off condition according to the airbag cut off switch cylinder status.
   
   

   Item		Airbag Cut Off Switch Cylinder Status
   		ON	OFF	Failure
   Passenger	Instrument Panel Passenger Airbag Assembly	Enabled	Disabled	Disabled
   	Seat Belt Pretensioner	Enabled	Enabled	Enabled
   	Instrument Panel Airbag Assembly Lower No. 2	Enabled	Disabled	Disabled
   AIRBAG OFF Indicator Light		Turn off	Turn on	Turn on

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 trouble is detected during the primary check, the SRS warning light remains on even after the 6 seconds have elapsed.
   





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

   
   
   
   

Airbag Sensor Assembly

1. The airbag sensor assembly consists of judgment circuits, a safing sensor, ignition control circuit, backup power source, diagnostic circuit and memory circuit.
   
   

   Item	Outline
   Judgment Circuit	Judgment circuits are built into the airbag sensor assembly to judge the severity of a collision using the acceleration/deceleration signals from the front airbag sensors, side airbag sensors and No. 2 side airbag sensors.
   Deceleration Sensor	A deceleration sensor is built into the airbag sensor assembly. This sensor distorts in the event of a collision. The amount of distortion is based on the deceleration rate of the vehicle during a frontal collision and is converted into an electric signal.
   Ignition Control Circuit	The ignition control circuit performs calculations based on the signal output from the judgment circuit of the airbag sensor assembly, front airbag sensors, side airbag sensors and No. 2 side airbag sensors. If the calculated values are greater than the specified values, the airbags are deployed.
   Safing Sensor	During a frontal, side or side rear collision, this sensor turns on and outputs an on signal to the airbag sensor assembly if a deceleration rate of the safing sensor is greater than a specified value.
   Backup Power Circuit	The backup power circuit consists of a power supply capacitor and a DC-DC converter. When the power supply to the airbag sensor assembly is disrupted during a collision, the power supply capacitor discharges and supplies electric power to the system. The DC-DC converter operates as a boosting transformer when the battery voltage falls below a predetermined level.
   Diagnostic Circuit	The diagnostic circuit constantly monitors for system malfunctions. When a malfunction is detected, it turns on the SRS warning light in the combination meter assembly to inform the driver.
   Memory Circuit	When a malfunction is detected by the diagnostic circuit, a code is stored in memory.

Horn Button Assembly

1. The horn button assembly contains a set of 2 initiators and propellants. The airbag sensor assembly helps optimize the airbag deployment rate by controlling the ignition timing of the initiators.
   

   
   
   
   
   

   Text in Illustration 

   *1	Bag	*2	Inflator
   *3	1st Initiator Connector	*4	2nd Initiator Connector
   *a	A-A Cross Section	*b	Reverse Side

Instrument Panel Passenger Airbag Assembly

1. Instrument panel passenger airbag assembly contains a set of 2 initiators and propellants. The airbag sensor assembly helps optimize the airbag deployment rate by controlling the ignition timing of these initiators.
   





2. When the instrument panel passenger airbag assembly is deployed, it forms the shapes of 2 bags with a depression in the middle. Immediately after the airbag is deployed, the shapes of 2 bags support the occupant on many planes, including the head and shoulders. Thus, this airbag disperses the load that is applied to the occupant in order to lessen the localized impact that is applied to the occupant immediately upon deployment.
   

   
   
   
   
   

   Text in Illustration 

   *1	1st Initiator Connector	*2	2nd Initiator Connector
   *3	Inflator	*4	Bag
   *5	Depression	-	-
   *a	A-A Cross Section	-	-

Instrument Panel Airbag Assembly Lower No. 1 and Instrument Panel Airbag Assembly Lower No. 2

1. Each knee airbag assembly consists of an airbag door, inflator and a bag.
   

   
   
   
   
   

   Text in Illustration 

   *1	Instrument Panel Airbag Assembly Lower No. 1	*2	Instrument Panel Airbag Assembly Lower No. 2
   *3	Inflator	*4	Bag
   *a	A-A Cross Section	-	-

Front Seat Airbag Assembly

1. Each front seat airbag assembly is a one-piece design, consisting of an inflator and a bag.
   

   
   
   
   
   

   Text in Illustration 

   *1	Front Seat Airbag Assembly	*2	Inflator
   *3	Bag	-	-
   *a	A-A Cross Section	*b	B-B Cross Section

Curtain Shield Airbag Assembly

1. Each curtain shield airbag assembly is a one-piece design, consisting of an inflator and a bag.
   

   
   
   
   
   

   Text in Illustration 

   *1	Curtain Shield Airbag Assembly	*2	Inflator
   *3	Bag	-	-
   *a	A-A Cross Section	-	-

Front Airbag Sensor

1. The front airbag sensors are an electrical type deceleration sensor. As a result of the deceleration of the vehicle during a frontal collision, a distortion is created in an internal element in the sensor and converted into an electrical signal. Accordingly, the extent of the initial collision can be detected in detail.
   

   
   
   
   

Side Airbag Sensor and No. 2 Side Airbag Sensor

1. A deceleration sensor is enclosed in the side airbag sensor and No. 2 side airbag sensor. As a result of the deceleration of the vehicle during a side or side rear collision, a distortion is created in an internal element in the sensor and converted into an electrical signal.
   

   
   
   
   

Seat Position Airbag Sensor

1. The seat position airbag sensor, which uses a Hall IC, detects changes in the magnetic flux that occurs due to the movement of the upper rail.
   

   
   
   
   
   

   Text in Illustration 

   *A	Models with Power Seat	*B	Models without Power Seat
   *1	Seat Position Airbag Sensor	-	-
   *a	Seat position is rearward	*b	Seat position is frontward

Front Seat Inner Belt Assembly (Seat Belt Buckle Switch)

1. A non-contact type switch is built into the front seat inner belt assembly (seat belt buckle switch) on the driver and front passenger sides.
   

2. The non-contact type switch contains a Hall IC and magnet.
   

3. The ejector inside the front seat inner belt assembly (seat belt buckle switch) and the plate installed to the ejector move when the seat belt is removed or inserted. The movement of the plate changes the magnetic flux density of the magnet.
   





4. The Hall IC detects changes in the magnetic flux density. These changes indicate that the seat belt is either fastened or unfastened, and the Hall IC outputs a signal to the airbag sensor assembly.
   

   
   
   
   
   

   Text in Illustration 

   *1	Ejector	*2	Magnet
   *3	Hall IC	*4	Plate
   *5	Magnetic Flux	-	-
   *a	Seat belt not fastened	*b	Seat belt fastened

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

The airbag sensor assembly outputs the malfunction data, 5-digit Diagnostic Trouble Codes (DTCs), to the intelligent tester.

The 5-digit DTCs can be read after connecting the intelligent tester to the DLC3. For details, refer to the Repair Manual.

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