Grand Cherokee 2WD V8-4.7L VIN J (2004)
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 Airbag Control Module (ACM) 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 ACM 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 side 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. The front and rear tethers keep the side curtain bag taut, thus
ensuring that the bag will deploy in the proper position. Following the airbag deployment, the airbag cushion quickly 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.