Side Curtain Air Bag - Operation

OPERATION

Each side curtain airbag is deployed individually by an electrical signal generated by the Occupant Restraint Controller (ORC) (also known as the lowline or highline airbag control unit/ARCADE) to which it is connected through left or right curtain airbag line 1 and line 2 (or squib) circuits. The hybrid-type inflator assembly for each airbag contains a small canister of highly compressed inert gas. When the ORC sends the proper electrical signal to the airbag inflator, the electrical energy creates enough heat to ignite chemical pellets within the inflator.

Once ignited, these chemicals burn rapidly and produce the pressure necessary to rupture a containment disk in the inert gas canister. The inflator and inert gas canister are sealed and connected to a tubular manifold so that all of the released gas is directed into the folded curtain airbag cushion, causing the cushion to inflate. As the airbag cushion inflates it will split the garnish molding at a predetermined breakout line and drop down from the roof rail along the side glass and body pillars to form a curtain-like cushion to protect the vehicle occupants during a side impact collision.

The front tether keeps the front portion of the side curtain bag taut, thus ensuring that the bag will deploy in the proper position. The tether on the back of the A-pillar trim controls the travel of this trim piece as it is displaced by the inflating curtain airbag. Following the airbag deployment, the airbag cushion deflates by venting the inert gas through the loose weave of the cushion fabric, and the deflated cushion hangs down loosely from the roof rail.

Proper diagnosis of the side curtain airbag inflator and squib circuits requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic information.