Driver Airbag

Fig. 16 Driver Airbag Trim Cover:

DRIVER AIRBAG
The airbag protective trim cover is the most visible part of the driver side airbag system. The protective trim cover is fitted to the front of the airbag module and forms a decorative cover in the center of the steering wheel. The module is mounted directly to the steering wheel. Located under the trim cover are the horn switch, the airbag cushion, and the airbag cushion supporting components. The airbag module includes a housing to which the cushion and hybrid inflator are attached and sealed. The airbag module cannot be repaired, and must be replaced if deployed or in any way damaged.


The color-keyed, injection molded, thermoplastic driver airbag protective trim cover is the most visible part of the driver airbag. The driver airbag is located in the center of the steering wheel, where it is secured with two screws to the armature of the four-spoke steering wheel. All models have a Dodge Ram logo embossed in the center of the trim cover. Concealed beneath the driver airbag trim cover are the horn switch, the folded airbag cushion, the airbag cushion retainer, the airbag housing, the airbag inflator, and the retainers that secure the inflator to the airbag housing. The airbag cushion, housing, and inflator unit is secured within an integral receptacle on the back of the trim cover by metal tabs engaged in slotted locking blocks at the top and bottom, by a metal hook through a window at each side, and by three aluminum blind rivets.

Fig. 17 Driver Airbag Housing:

The resistive membrane-type horn switch is secured with heat stakes to the inside surface of the driver airbag trim cover, between the trim cover and the folded airbag cushion. The horn switch ground pigtail wire has an eyelet terminal connector that is captured beneath a nut and washer on the upper left inflator mounting stud on the back of the housing. The horn switch feed pigtail wire has a black, molded plastic insulator and is connected to the vehicle electrical system through a connector receptacle on the clockspring. Both horn switch wires are routed through integral routing slots in the upper locking block of the trim cover receptacle.

The airbag used in this model is a Next Generation-type that complies with revised federal airbag standards to deploy with less force than those used in some prior models. A 71.1 centimeter (28 inch) diameter, radial deploying fabric cushion with internal tethers is used. The airbag inflator is a non-azide, pyrotechnic-type unit and is secured by four hex nuts to four studs on the airbag cushion retainer ring to the back of the stamped metal airbag housing. A connector receptacle on the driver airbag inflator connects the inflator initiator to the vehicle electrical system through a yellow-jacketed, two-wire pigtail harness of the clockspring. The driver airbag and horn switch unit cannot be repaired, and must be replaced if deployed or in any way damaged.

The driver airbag is deployed by electrical signals generated by the Airbag Control Module (ACM) through the driver airbag squib circuit to the initiator in the airbag inflator. When the ACM sends the proper electrical signal to the initiator, the electrical energy generates enough heat to initiate a small pyrotechnic charge which, in turn ignites chemical pellets within the inflator. Once ignited, these chemical pellets burn rapidly and produce a large quantity of inert gas. The inflator is sealed to the back of the airbag housing and a diffuser in the inflator directs all of the inert gas into the airbag cushion, causing the cushion to inflate. As the cushion inflates, the driver airbag trim cover will split at predetermined breakout lines, then fold back out of the way along with the horn switch unit. Following an airbag deployment, the airbag cushion quickly deflates by venting the inert gas towards the instrument panel through vent holes within the fabric used to construct the back (steering wheel side) panel of the airbag cushion.

Some of the chemicals used to create the inert gas may be considered hazardous while in their solid state before they are burned, but they are securely sealed within the airbag inflator. Typically, all potentially hazardous chemicals are burned during an airbag deployment event. The inert gas that is produced when the chemicals are burned is harmless. However, a small amount of residue from the burned chemicals may cause some temporary discomfort if it contacts the skin, eyes, or breathing passages. If skin or eye irritation is noted, rinse the affected area with plenty of cool, clean water. If breathing passages are irritated, move to another area where there is plenty of clean, fresh air to breath. If the irritation is not alleviated by these actions, contact a physician.