Air Bag Control Module: Description and Operation

DESCRIPTION





The Occupant Restraint Controller (ORC) (1) is secured with three screws to a stamped steel mounting bracket welded onto the top of the floor panel transmission tunnel near the base of the dash panel and just forward on the center instrument panel support in the passenger compartment of the vehicle. Concealed within a hollow in the center of the die cast aluminum ORC housing is the electronic circuitry of the ORC which includes a microprocessor, an electronic impact sensor, an electronic safing sensor and an energy storage capacitor. A stamped metal cover plate is secured to the bottom of the ORC housing with five screws to enclose and protect the internal electronic circuitry and components.

An arrow printed on the label (2) on the top of the ORC housing provides a visual verification of the proper orientation of the unit, and should always be pointed toward the front of the vehicle. The ORC housing has three integral mounting tabs and two integral locating pins. The molded plastic electrical connector (3), with two receptacles containing numerous terminal pins, exits the rearward facing side of the ORC housing. These terminal pins connect the ORC to the vehicle electrical system through two dedicated take outs and connectors, one from the body wire harness and one from the instrument panel wire harness.

The impact sensor and safing sensor internal to the ORC are calibrated for the specific vehicle, and are only serviced as a unit with the ORC. In addition, there are unique versions of the ORC for vehicles with or without side curtain airbags or seat (thorax) airbags, as well as for those vehicles with domestic or export applications. The ORC cannot be repaired or adjusted and, if damaged or ineffective, it must be replaced.