Air Bag, Passenger: Operation: Operation

WARNING: This page is about a different car, the 2014 Dodge Journey. However, it is still accessible from the selected car via links, so may be relevant.

The multistage Passenger AirBag (PAB) is deployed by electrical signals generated by the Occupant Restraint Controller (ORC) through the PAB squib 1 and squib 2 circuits to the two initiators in the airbag inflator. By using two initiators, the PAB 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 multiple 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 PAB door will split at predetermined tear seam lines concealed on the inside surface of the door, 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 a discrete vent hole in each fabric side panel of the airbag cushion.

Domestic market vehicles are equipped with an active vent tether cutter unit. The ORC monitors a seat track position sensor on the passenger front seat. If the seat is in the full forward position when an airbag deployment occurs, the ORC signals the tether cutter to cut the tether that normally keeps active vent flaps in the airbag cushion closed. With the tether cut, the active vents open to reduce airbag deployment force and reduce the possibility of an airbag-induced injury when the passenger is seated close to the deploying airbag. If the passenger front seat is not in the full forward position, the tether is not cut and the active vents in the cushion remain closed during deployment.

Typically, both initiators are used during a PAB deployment event. However, it is possible for only one initiator to be used during a deployment due to an airbag system fault and, it is also possible that the tether cutter was not used during a deployment. It is necessary to always confirm that both initiators and the tether cutter have been used in order to avoid the improper disposal of potentially live pyrotechnic materials. Refer to STANDARD PROCEDURE .

The ORC monitors the condition of the PAB through circuit resistance, and will illuminate the airbag indicator in the instrument cluster and store a Diagnostic Trouble Code (DTC) for any fault that is detected. Proper diagnosis of the PAB inflator and squib circuits requires the use of a diagnostic scan tool and may also require the use of the SRS Load Tool special tool along with the appropriate Load Tool Jumpers and Adapters. Refer to the appropriate diagnostic information.