PASSENGER AIRBAG

The horizontal surface of the instrument panel top pad (1) above the glove box is the most visible part of the passenger airbag. The passenger airbag door is integral to the top of the instrument panel top pad above the glove box opening on the instrument panel in front of the front seat passenger seating position.

Located below the passenger airbag door area of the instrument panel top pad, the molded thermoplastic passenger airbag retainer is secured to the underside of the top pad. The retainer defines the airbag door breakout area of the top pad and serves as the receptacle for the passenger airbag cushion and housing. Numerous small window openings on the forward and rearward flanges of the receptacle receive mating hook formations stamped into the airbag housing, which locate and secure the housing to the top pad.

The passenger airbag unit (1) is also secured by two screws through a stamped mounting bracket (3) to the instrument panel structural support. The passenger airbag unit used in this vehicle is a multistage type that complies with revised federal airbag standards to deploy with less force than those used in some prior vehicles. The passenger airbag unit consists of a stamped and welded metal housing, the airbag cushion, and the airbag inflator (5). The airbag housing contains the airbag inflator and the folded airbag cushion. An approximately 80 centimeter (31.5 inch) wide by 90 centimeter (35.5 inch) high rectangular fabric cushion is used.

The airbag inflator (5) is a non-azide, pyrotechnic-type unit that is secured to and sealed within the airbag housing. A short four-wire pigtail harness with a keyed, yellow connector insulator (4) connects the two inflator initiators (2) to the vehicle electrical system through a dedicated take out and connector of the instrument panel wire harness.

The passenger airbag cannot be repaired, and must be replaced if deployed, ineffective, or in any way damaged. The passenger airbag door and retainer are serviced only as a unit with the instrument panel top pad. If the passenger airbag is deployed, the instrument panel top pad must also be replaced.

OPERATION

The multistage passenger airbag is deployed by electrical signals generated by the Occupant Restraint Controller (ORC) through the passenger airbag squib 1 and squib 2 circuits to the two initiators in the airbag inflator. By using two initiators, the airbag can be deployed at multiple levels of force. The force level is controlled by the ORC to suit the monitored impact conditions by providing one of four delay intervals between the electrical signals provided to the two initiators. The longer the delay between these signals, the less forcefully the airbag will deploy.

When the ORC sends the proper electrical signals to each 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 airbag cushion 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 passenger airbag door area of the instrument panel top pad will split at predetermined tear seam lines concealed on the underside of the top pad, then the door will pivot up over the top of the instrument panel and out of the way. Following an airbag deployment, the airbag cushion quickly deflates by venting the inert gas through vent holes within the fabric used to construct the back (windshield side) of the airbag cushion.

INSTALLATION

WARNING: To avoid personal injury or death, on vehicles equipped with airbags, disable the supplemental restraint system before attempting any steering wheel, steering column, airbag, seat belt tensioner, impact sensor, or instrument panel component diagnosis or service. Disconnect and isolate the battery negative (ground) cable, then wait two minutes for the system capacitor to discharge before performing further diagnosis or service. This is the only sure way to disable the supplemental restraint system. Failure to take the proper precautions could result in accidental airbag deployment.

WARNING: To avoid personal injury or death, when removing a deployed airbag, rubber gloves, eye protection, and a long-sleeved shirt should be worn. There may be deposits on the airbag unit and other interior surfaces. In large doses, these deposits may cause irritation to the skin and eyes.

WARNING: Use extreme care to prevent any foreign material from entering the passenger airbag, or becoming entrapped between the passenger airbag cushion and the instrument panel top pad. Failure to observe this warning could result in occupant injuries upon airbag deployment.

WARNING: The instrument panel top pad must never be painted. Replacement top pads are serviced in the original colors. Paint may change the way in which the material of the top pad responds to an airbag deployment. Failure to observe this warning could result in occupant injuries upon airbag deployment.