Air Bag, Seat: Operation: Rear

WARNING: This page is about a different car, the 2017 Jeep Cherokee. However, it is still accessible from the selected car via links, so may be relevant.

Each rear Seat AirBag (SAB) is deployed individually by an electrical signal generated by the Occupant Restraint Controller (ORC) to which it is connected through left or right rear SAB line 1 and line 2 (or squib) circuits. Each SAB has a pyrotechnic-type Micro Gas Generator (MGG) inflator assembly.

When the ORC sends the proper electrical signal to the SAB inflator initiator, the electrical energy creates 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 it will split the fabric wrap, the pouch (intensifier) integral to the seat cushion trim cover and the outboard side of the seat cushion trim cover, then expand into the area between the outboard side of the rear seat and the rear door to form a cushion to protect the rear seat occupant during a side impact collision or a vehicle rollover incident.

Following the rear SAB deployment, the cushion slowly deflates by venting the inert gas through the loose weave of the cushion fabric and through a vent in the cushion. After venting is achieved, the deflated cushion hangs down loosely from the outboard side of the rear seat cushion.

The ORC monitors the condition of the rear seat airbags through circuit resistance. If any fault is detected the ORC will illuminate the airbag indicator in the instrument cluster and store a Diagnostic Trouble Code (DTC). Proper diagnosis of the rear SAB 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.