Commander 4WD V8-4.7L VIN N (2006)
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 model is a multistage type that complies with revised federal airbag standards to deploy with less force than those used
in some prior models. 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, faulty, 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.
Typically, both initiators are used during an airbag deployment event. However, it is possible for only one initiator to be used during a deployment due to
an airbag system fault; therefore, it is necessary to always confirm that both initiators have been used in order to avoid the improper disposal of
potentially live pyrotechnic materials.
