Vehicles Built 02/2000 Onwards
Air Bag and Safety Belt Pretensioner Supplemental Restraint System (SRS):
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.
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 windscreen edge of the instrument panel.
Vehicles equipped with side air bag modules can be identified by an embossed AIRBAG logo on the seat fabric adjacent to the air bag module. A label is attached to the B-pillar adjacent to the seat.
WARNING: ALL VEHICLES FITTED WITH THE PASSENGER AIR BAG FROM THE FACTORY HAVE A WARNING STICKER ATTACHED TO THE SUN VISOR, PROHIBITING THE USE OF REAR FACING CHILD OR BABY SEATS.
The air bag system consists of the following components:
1. air bag control module
2. wiring harness
3. air bag sliding contact
4. warning indicator
5. air bag module(s)
6. side impact crash sensors (when equipped with side air bags)
7. driver safety belt retractor and pretensioner
8. passenger safety belt buckle and pretensioner
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. These two sensors are connected in series and if they both sense a deceleration in excess of a predetermined limit, the air bag control module will deploy the air bag module(s), the driver safety belt retractor pretensioner and the passenger safety belt buckle pretensioner.
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 performs continual system diagnostics. In the event of a fault being detected the warning indicator is illuminated either constantly or intermittently. The behavior of the warning indicator depends on the type of fault present. The warning indicator is located in the instrument cluster.
Both the driver safety belt retractor pretensioner and the passenger safety belt buckle pretensioner are deployed simultaneously by the air bag control module, even if the passenger seat is unoccupied.
The driver safety belt retractor pretensioner and the passenger safety belt buckle pretensioner have a slightly lower triggering threshold than the air bag module(s) and will therefore deploy first.
In the event that the air bag module(s) deploy, the driver safety belt retractor pretensioner and the passenger safety belt buckle pretensioner will also always deploy.
Under certain circumstances the deceleration value, recorded by the air bag sensors, may reach the driver safety belt retractor pretensioner and passenger safety belt buckle pretensioner threshold but does not exceed the air bag module threshold. In such circumstances only the driver safety belt retractor pretensioner and passenger safety belt buckle pretensioner will deploy.
The wiring harness provides power to the air bag control module from the vehicle supply and hence to the air bag module(s), side impact crash sensors (if equipped with side air bags), safety belt pretensioners and the warning indicator.
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. 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.
Driver And Passenger Air Bag Module Inflator:
The driver, passenger and side air bag modules consist of the following components which cannot be disassembled.
^ inflator
^ air bag
^ container
^ cover
The inflator is screwed into a metal cup-shaped container. The air bag is then folded on top of the inflator and the whole subassembly is enclosed by the cover.
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 surface 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 instrument panel top to provide an unobtrusive appearance. The cover, which is a one-piece moulding, incorporates an invisible "bend line" in its surface. The cover is attached to the instrument panel by retaining clips and secured to the air bag module by a bracket. As the air bag module deploys, the cover is forced free of the retaining clips and bends along the "bend line", allowing the air bag to easily exit. The cover remains secured to the air bag module body by the bracket.
The side air bag module(s) are integrated into the front seat backrests providing an unobtrusive appearance. The unique seat cover has been designed to accommodate air bag deployment. When the side air bag is deployed the stitched seam of the seal cover adjacent to the side air bag module splits, allowing the air bag to exit the seat backrest unobstructed.
The purpose of the inflator is to generate the gas needed to fill the air bag. It consists of a high strength steel casing filled with a solid propellant charge and an electrically activated igniter. The igniter is activated by a signal from the air bag control module, which in turn ignites the propellant charge. The very rapid burning of the propellant produces sufficient gas to fill the air bag(s). As the gases expand they cool, preventing heat damage to the bag. The driver air bag module has a single inflator and an air bag, which has a filled volume of 45 litres. The passenger air bag module has a single inflator and an air bag, which has a filled volume of 130 litres. The side air bag modules have single inflators and air bags, which have filled volumes of 12 litres.
The air bag(s) are a one-piece woven item with a silicon coating to provide flame and heat protection in the vicinity of the inflator. The shape of the passenger and side air bags (when equipped) is tailored to the vehicle proportions.
The SRS will communicate faults/concerns during a driving cycle or after initial key ON by means of a warning indicator located in the instrument cluster
Lamp Fault Codes (LFC):
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 nonvolatile memory.