Grand Cherokee 2WD V8-5.7L VIN 2 (2005)
Air Bag: Description and Operation
Curtain Airbag
Optional side curtain airbags are available for this model when it is also equipped with dual front airbags. These airbags are passive, inflatable,
Supplemental Restraint System (SRS) components, and vehicles with this equipment can be readily identified by a molded identification trim button with
the "SRS - AIR-BAG" logo located on the head liner above each B-pillar. This system is designed to reduce injuries to the vehicle occupants in the event
of a side impact collision.
Vehicles equipped with side curtain airbags have two individually controlled curtain airbag units. These air-bag units are concealed and mounted above
the headliner where they are each secured to one of the roof side rails. Each folded airbag cushion is contained within a long extruded plastic channel
that extends along the roof rail from the A-pillar at the front of the vehicle to just behind the C-pillar at the rear of the vehicle. A long tether extends
down the A-pillar from the front of the airbag cushion. The end of the tether is secured to a slot in the sheet metal with a metal hook, while two
additional plastic clips secure the tether to the inside of the A-pillar.
The hybrid-type inflator for each airbag is secured to the roof rail at the rear of the airbag unit between the C-pillar and the D-pillar, and is connected to
the airbag cushion by a long tubular manifold. The inflator bracket and the extruded airbag cushion channel are secured with both plastic push-in
fasteners and screws to the roof rail. The inflator is initially hung from the roof rail by hooks that are integral to the inflator bracket. The airbag inflator is
connected to the vehicle electrical system through a dedicated take out and connector of the body wire harness near the top of the D-pillar.
The side curtain airbag unit cannot be adjusted or repaired and must be replaced if deployed, faulty, or in any way damaged. Once a side curtain airbag
has been deployed, the complete airbag unit, the headliner, the upper A, B, and C-pillar trim, and all other visibly damaged components must be
replaced.
Each side curtain airbag is deployed individually by an electrical signal generated by the Occupant Restraint Controller (ORC) 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 drop down from the roof rail between the edge of the headliner and the side glass/body pillars
to form a curtain-like cushion to protect the vehicle occupants during a side impact collision.
