AIR BAG SYSTEM [TWO-STEP DEPLOYMENT CONTROL SYSTEM]

Outline

• With the air bag system, the SAS control module operates (deploys) the air bags according to the degree of impact during the collision to supplement the occupant protection function of the seat belts.

WARNING:

• The air bag system supplements the occupant protection function of the seat belts, however the intended effect of the air bag system cannot be obtained if the seat belts are not fastened correctly. When driving the vehicle, always fasten the seat belts correctly.

Function

• With the air bag system, the SAS control module calculates the degree of impact based on the collision detection signal from each of the following sensors, and operates (deploys) the required parts.

^*1

Operates (deploys) by degree of impact during collision.

^*2

Operates (deploys) on the side the collision is detected.

Driver-side/passenger-side air bag deployment force switching function (two-step deployment)

• The driver-side/passenger-side air bag deployment force switching function switches the driver-side/passenger-side air bag deployment force by deploying inflators No.1 and 2 built into the driver-side/passenger-side air bag module simultaneously or only inflator No.1^*1 according to the degree of impact from a frontal or frontal offset collision and seat belt fastening status.

^*1

If the SAS control module deploys only inflator No.1, it deploys inflator No.2 soon afterwards to not leave it undeployed.

System conditions display function

• The air bag system detects each part condition and the SAS control module sends the system status signal to the instrument cluster.

• The instrument cluster notifies the user of the system conditions using the following warning light or alarm based on the system condition signal.

Structural View

System Wiring Diagram

Operation

Collision from front of vehicle or frontal offset

1. When an impact from a frontal or frontal offset collision (1) is received, the crash sensor built into the crash zone sensor and the crash sensor (2) built into the SAS control module detect the impact and convert the impact into an electrical signal at the signal processing circuit (3).

2. The SAS control module calculates (6) the degree of impact using the determination and safing circuit (5) based on the electric signal (4) from each crash sensor.

3. If the calculated degree of impact exceeds the previously set threshold, the SAS control module outputs (8) an operation (deployment) signal to each air bag module or pre-tensioner seat belt at the output control circuit (7).

4. Each air bag module or pre-tensioner seat belt operates (deploys) (9) based on the operation (deployment) signal from the SAS control module.

Collision from side of vehicle

1. When an impact (1) from a lateral collision is received, the following sensors (2) detect the impact and convert the impact or the pressure into an electrical signal at the signal processing circuit (3).

• Crash sensor integrated into side air bag sensor

• Crash sensor integrated into SAS control module

• Pressure detection sensor integrated into pressure sensor

2. The SAS control module calculates (6) the degree of impact using the determination and safing circuit (5) based on the electric signal (4) from each crash sensor or the pressure detection sensor.

3. If the calculated degree of impact exceeds the previously set threshold, the SAS control module outputs (8) an operation (deployment) signal to the side air bag module or pre-tensioner seat belt at the output control circuit (7).

4. The side air bag module or pre-tensioner seat belt operates (deploys) (9) based on the operation (deployment) signal from the SAS control module.