Caliber L4-2.4L (2009)
DESCRIPTION
The injection molded, thermoplastic Inflatable Knee Blocker (IKB) airbag protective trim cover (1) is the most visible part of the knee blocker airbag.
The IKB airbag is located below the steering column in the instrument panel steering column opening cover (2) on the driver side of the vehicle. It is
secured with two screws to the instrument panel support structure and by multiple integral latch features to the rectangular opening in the steering column
opening cover. The IKB trim cover can be readily identified by the SRS AIRBAG text molded into one upper corner.
Concealed beneath the IKB trim cover are the folded airbag cushion, the airbag housing, the airbag inflator and the retainer that secures the inflator to
the housing. The airbag cushion (2), a stamped steel housing (4), and an inflator initiator (3) are secured within an integral receptacle molded into the
back of the trim cover. The upper and lower vertical walls of this receptacle have numerous small windows that are engaged by numerous hook
formations (1) on the upper and lower edges of the airbag housing. Each hook is inserted through one of the windows, locking the trim cover securely
into place on the airbag housing. The two outer mounting studs extending from the housing secure the airbag to the instrument panel support structure.
The center stud secures the airbag cushion retainer and inflator within the housing.
The IKB airbag cannot be repaired, and must be replaced if deployed, ineffective, or in any way damaged. The IKB airbag trim cover may be
disassembled from the driver airbag unit, and is available for individual service replacement. Following an IKB airbag deployment, the IKB airbag and
the instrument panel support structure assembly must be replaced.
Knee Blocker Air Bag - Operation
OPERATION
The Inflatable Knee Blocker (IKB) airbag is deployed by an electrical signal generated by the Occupant Restraint Controller (ORC) through the IKB
airbag squib circuit to the initiator in the airbag inflator. When the ORC sends the proper electrical signal to the 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 back of the airbag housing 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 IKB airbag trim cover
will split at predetermined breakout lines, then fold down out of the way. Following an airbag deployment, the airbag cushion quickly deflates by venting
