The supplemental restraint system (SRS) has been specifically designed to protect the driver and passenger, from sustaining severe facial and upper body injuries in the event of a serious impact. Optimum protection can only be achieved when used in conjunction with a conventional three-point safety belt. The safety belts form an integral part of the SRS.
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Air bag warning indicator
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Passenger air bag module
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Side air curtain module (driver side shown)
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Rear side impact sensor (driver side shown)
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Side air bag module (driver side shown)
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Front side impact sensor (driver side shown)
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Air bag sliding contact
The visible VIN plate, which shows the air bag symbol and either X1 or X2 dependent on the number of air bags fitted, is attached to the windshield edge of the instrument panel.
Vehicles equipped with side air bags can be identified by an embossed AIRBAG logo on the side air bag module trim cover, which forms part of the seat trim.
Side air curtains are available on vehicles built from 2003.25MY.
Side Air Curtain
It is not possible under any circumstances to disable the passenger air bag while maintaining the integrity of the whole air bag system.
The air bag system consists of the following components:
- air bag control module
- wiring harness
- air bag sliding contact
- warning indicator
- air bag module(s)
- side impact sensors
The air bag control module governs the operation of the whole system, including the diagnostic element. It contains two frontal impact micro machine sensors; a crash sensor and a safing sensor. The air bag control module discriminates between two threshold values. In the event that the air bag control module senses a deceleration in excess of the first predetermined limit, the air bag control module will initiate the fuel cut-off solenoid to cut the fuel off. In addition the central locking relay is actuated to unlock the doors and illuminate the interior lighting. This threshold is approximately the same as that required to actuate the mechanical safety belt pretensioners. When the deceleration value exceeds the second predetermined limit, the air bag module(s) will be deployed.
The air bag control module will also deploy the corresponding side air bag module dependent on the signal received from the crash sensor.
The air bag control module also carries out continual system diagnostics. In the event of a fault being detected the warning indicator is illuminated either constantly or intermittently. The SRS will communicate faults or concerns during a driving cycle or after initial key ON by means of a warning indicator located in the instrument cluster. The behavior of the warning indicator depends on the type of fault present.
The wiring harness provides power to the air bag control module from the vehicle supply and hence to the air bag module(s).
The air bag sliding contact is designed to carry signals between the air bag control module and the driver air bag module. The air bag sliding contact is fitted to the steering column, and consists of fixed and moving parts connected by a coiled Mylar tape with integral conducting tracks. The Mylar tape is able to "wind up" and "unwind" as the steering wheel (to which the moving part is attached) is turned, maintaining electrical contact at all times between the air bag control module and the driver air bag module. Vehicles equipped with stability assist incorporate the steering wheel rotation sensor within the air bag sliding contact. The air bag sliding contact is used in order to achieve the high degree of circuit integrity required by such a critical safety system as the SRS.
The driver air bag module is fitted to the steering wheel, the cover forming the outer surface of the steering wheel boss. The cover has invisible "split lines" moulded in its surfaces allowing the air bag to easily exit through the cover when the system deploys.
The passenger air bag module is located above the glove compartment and is integrated into the upper instrument panel to provide an unobtrusive appearance. In the event that the passenger air bag module deploys a new upper instrument panel must be installed.
The side air bag module(s) are integrated into the front seat backrests providing an unobtrusive appearance.
The side air curtain modules are located under the headliner between the A and D-pillar and are only available in conjunction with side air bags. When deployed, the side air curtain module extends down approximately shoulder height to protect both the front and rear occupants heads. Both the front and rear of the side air curtain module are retained by cords to hold it in position on deployment.
If a concern is detected, the air bag control module will communicate by flashing the warning indicator. A diagnostic trouble code (DTC) is logged by the air bag control module in a non-volatile memory. The DTC can be down loaded using worldwide diagnostic system (WDS).
For additional information, refer to: Air Bag Supplemental Restraint System (SRS) (501-20 Supplemental Restraint System, Diagnosis and Testing).
