SRS AIRBAG
The SRS airbags supplement the seat belts which restrain the body if the driver or passenger is endangered by a severe impact to the front of the vehicle.
If an impact whose magnitude exceeding the preset value is applied to the vehicle, the airbags inflate immediately to prevent the driver and front seat passenger being hit against the steering wheel, instrument panel or windshield.
A two-staged inflator whose airbag inflation speed is changed according to the magnitude of the impact is used.
SRS SIDE AIRBAG
The SRS side airbag supplements the seat belts which restrain the body if the driver or passenger is endangered by a severe impact to the side of the vehicle.
If an impact whose magnitude exceeding the preset value is applied to the side of the vehicle, the side airbags inflate immediately to soften the impact to the driver or front seat passenger especially at their chest area.
SRS CURTAIN AIRBAG
The SRS curtain airbag supplements the seat belts which restrain the body if the driver or passenger is endangered by a severe impact to the side of the vehicle.
If an impact whose magnitude exceeding the preset value is applied to the side of the vehicle, the curtain airbag inflates immediately to soften the impact to the passengers especially at their head area.
SEAT BELT PRETENSIONER
The seat belt pretensioner improves efficiency of body restraint by retracting the seat belt immediately if the driver or passenger is endangered by a severe impact to the front of the vehicle.
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COMPONENTS
| Name | Major function | Location |
|---|---|---|
| Airbag control module | Senses impact and judges its magnitude by means of a safety sensor and G sensor built inside. Serves as supplementary power supply if the battery voltage is lowered for some reason. Directs airbags to inflate. Performs self diagnosis of the airbag system. | Inside center console. |
| Driver's seat airbag module | Protects the driver's head and upper body to minimize injury in an event of frontal collision. | Stowed inside the pad at the center of the steering wheel. |
| Passenger's seat airbag module | Protects the passenger's head and upper body to minimize injury in an event of frontal collision. | Stowed inside the instrument panel at the front passenger's side. |
| Driver's seat side airbag module | Protects the driver's upper body to minimize injury in an event of side collision. | Stowed inside the driver's seat backrest. |
| Passenger's seat side airbag module | Protects the front passenger's upper body to minimize injury in an event of side collision. | Stowed inside the front passenger's seat backrest. |
| Curtain airbag module | Deploys together with the side airbag to protect the driver's or passenger's head and minimize injury in an event of side collision. | Stowed inside at left and right sides from the A pillars through the upper part of C pillars. |
| Steering roll connector | Provides electrical connection between the vehicle side airbag harness and steering wheel. | Between the combination switch and steering wheel. |
| Seat belt pretensioner | Retracts the seat belt immediately to restrain the body of front seat passengers in an event of a frontal collision. | Lower part of left and right B pillars. |
| Front sub sensor | Detects the impact in an event of a frontal collision and outputs a deceleration signal to the control module. | In front of left and right front frames. |
| Side airbag sensor | Senses impact and judges its magnitude in an event of a side collision by means of a safety sensor and G sensor built inside. Performs self diagnosis of the airbag system. | Inside the left and right B pillars. |
| Curtain airbag sensor | Senses impact and judges its magnitude in an event of a side collision by means of a safety sensor and G sensor built inside. Performs self diagnosis of the airbag system. | In front of rear left and right wheel arches. |
| Airbag warning light | Indicates whether the system is normal or abnormal. Displays diagnostic trouble codes. | Inside the combination meter. |
| Occupant detection control module | Decides whether an adult, child, or is nobody is sitting in the seat, based on the occupant detection sensor output. Performs self diagnosis of the occupant detection system. | Beneath the passenger's seat cushion. |
| Load cell sensor | Detects the load on the seat applied by the passenger. | On the passenger's seat slide rail. |
| Passenger's seat airbag ON/OFF indicator | Indicates whether the deployment of the passenger's seat airbag is allowed or not, based on the decision of the occupant detection system. | Center of the instrument panel at the clock area. |
| Buckle switch | Detects whether the seat belt is fastened or not. | At the seat belt buckle. |
| Seat position sensor (LH) | Detects the fore-aft position of the driver's seat and distinguishes the passenger. | On the driver's seat slide rail. |
Scheme 6
AIRBAG CONTROL MODULE
The airbag control module is installed inside the center console and contains a safety sensor, G sensor, ignition judgment circuit, and a backup power supply, etc.
The control module receives electric signals from the safety sensor and electric sensor inside the module and also from the front sub sensor to detect the deceleration of the vehicle and judge whether the airbag and pretensioners should be ignited or not. It also has a self diagnosis function which lights up the airbag warning light in the combination meter if a fault occurs in the system. Diagnostic trouble codes generated by the self diagnosis function are stored in the memory in the module.
To prepare for battery voltage fall in an event of an accident, the control module is provided with a backup power supply.
Scheme 7
- Safety sensor Inside of the sensor there is a mass weight, which works as a pendulum; if the sensor detects an impact acceleration exceeding a certain limit, the mass weight in the sensor moves to close the contacts and turn the switch ON.
- G sensor
Inside of the sensor there are comb-teeth shaped electrodes; in case of a collision the distance between the electrodes varies by the impact to enable detection of the impact acceleration.
DRIVER'S SEAT AIRBAG MODULE
The driver's seat airbag module is built in the steering wheel pad.
The SRS airbag module assembly cannot be disassembled. The driver's seat airbag module assembly consists of an inflator and airbag, and a steering wheel pad.
Scheme 8
The inflator houses igniters and gas generating agents in a metal container. Igniters and gas generating agents are placed at two locations, and a 2-stage inflator which controls the airbag inflating speed according to the magnitude of impact at a collision is used. If the impact detected by the airbag sensor is equivalent to the level detected at a high speed, sudden collision, the two gas heating agents are ignited simultaneously. If the event of a collision at low or mid speed, the ignition of the 2nd stage gas generating agent is delayed to reduce the output of the inflator. Thus the inflator outputs power suitable for the severity of collision and relieves the impact to the passenger's head or upper body.
Scheme 9
PASSENGER'S SEAT AIRBAG MODULE
The front passenger's seat SRS airbag module assembly is built in the instrument panel at the front passenger's side.
The SRS airbag module assembly cannot be disassembled. The front passenger's seat airbag module is fixed to the steering support beam, and consists of an inflator and an airbag.
Scheme 10
The inflator houses igniters and gas generating agents with a metal container. Igniters and gas generating agents are placed at two locations, and a 2-stage inflator which controls the airbag inflating speed according to the magnitude of impact at a collision is used. If the impact detected by the airbag sensor is equivalent to the level detected at a high speed, sudden collision, the two gas generating agents are ignited simultaneously. If the event of a collision at low or mid speed, the ignition of the 2nd stage gas generating agent is delayed to reduce the output of the inflator. Thus the inflator outputs power suitable for the severity of collision and relieves the impact to the passenger's head or upper body.
Scheme 11
SIDE AIRBAG MODULE
The side airbag modules are built in the backrest of left and right front seats (at the door side).
The SRS side airbag module assembly cannot be disassembled. The side airbag module is fixed to the seat frame with a bracket, and consists of an inflator, airbag, and a case.
If a side-on collision occurs, the inflator produces a certain amount of gas to inflate the airbag in a very short time in response to the ignition signal from the side impact sensor.
Scheme 12
CURTAIN AIRBAG MODULE
The curtain airbag modules are placed at the front pillars, roof sides, and the rear pillars.
The SRS curtain airbag module cannot be disassembled. The curtain airbag modules are fixed to the vehicle body with a bracket and clips, and consists of an inflator and an airbag.
If a side-on collision occurs, the inflator produces a certain amount of gas to inflate the airbag in a very short time in response to the ignition signal from the side airbag sensor and curtain airbag sensor.
Sedan models
Scheme 13
Wagon models
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STEERING ROLL CONNECTOR
The steering roll connector is in between the steering column and the steering wheel, and contains a spirally wound flat cable.
The flat cable maintains connection between the airbag module on the steering wheel and the airbag harness even when the steering wheel is turned. Ignition signal from the airbag control module is sent through the roll connecter to the driver's seat airbag module.
Scheme 15
The driver's and front passenger's seat belt retractors contain a seat belt pretensioner.
The airbag control module controls the operation of the seat belt pretensioner. If the front sub sensor and the sensors inside the airbag control module detect an impact exceeding a specified level, the driver's seat and front passenger's seat airbags are deployed almost simultaneously. Upon receiving signals from the airbag control module the gas generator inside the pretensioners are ignited and the gas pressure retracts the seat belts in a very short time to improve the passenger restraint effect.
If the load placed on a seat belt exceeds the predetermined level, the torsion bar is twisted to allow the seat belt to be pulled out, thus lessening the load imposed on the belt wearer's chest.
Once the seat belt pretensioner has been activated, the seat belt retractor remains locked.
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FRONT SUB SENSOR
The front sub sensor is installed to the tip of the front side frame.
If it detects an impact exceeding the specified level from the front, it sends a signal which is used for airbag system deployment judgment to the airbag control module.
To judge the impact to the front of the vehicle more precisely, the sensor is changed from the conventional pendulum type mechanical sensor to an electronic sensor.
Scheme 17
SIDE IMPACT SENSOR
The side impact sensors (side airbag sensor, curtain airbag sensor) are installed at the bottom of the center pillars and the rear quarter pillars.
If the sensor in the side impact sensor detects an impact exceeding the specified level from the side, it sends a signal which is used for airbag system deployment judgment to the airbag control module.
Signals from the side airbag sensors are effective for both the side airbags and curtain airbags, while signals from the curtain airbag sensors detect impact to the rear seat sides and let only the curtain airbags deploy.
Scheme 18
AIRBAG WARNING LIGHT
The airbag warning light is located inside the combination meter. It illuminates if a poor connection in the airbag circuit occurs, or if the airbag control module detects an abnormal condition. When the airbag system is normal, this light comes on when the ignition switch is turned ON and then goes out about 6 seconds later.
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GENERAL
The airbag system uses connectors with a double lock mechanism and an incomplete-coupling-detection mechanism for enhanced reliability. If coupling is incomplete, the airbag warning light comes on in the combination meter.
DRIVER'S SEAT AIRBAG MODULE-TO-SEAT BELT PRETENSIONER CONNECTOR
Disconnection
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- Lift the lock button using a thin tipped tool like a miniature screwdriver.
- Pull the connector out from the airbag module.
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Connection
Carefully insert the connector into the airbag module. Push the connector until a "click" is heard from the lock button.
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Disconnection
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- Press the slide lock inwards.
- While the slide lock pressed in, disconnect the connector (A).
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Connection
Insert the female side connector half into the other until a "click" is heard.
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Disconnection
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- Push in and hold the lock arm (A), then pull the slide lock (B).
- While the slide lock pulled and held (B), release the lock arm (C).
- While the slide lock pulled and held (B), disconnect the connector (D).
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Connection
Insert the female side connector half into the other until a "click" is heard.
FRONT SUB SENSOR, SIDE AIRBAG SENSOR, CURTAIN AIRBAG SENSOR, AND SEAT POSITION SENSOR (LH) CONNECTORS
Disconnection
Holding the outer part (A), pull the connector in the direction of the arrow.
Scheme 29
Connection
Holding the inner part, push the connector into the socket carefully until a "click" is heard. Do not hold the outer part (A) as it moves back during connection of the connector.
