Occupant Restraint Controller: Operation

There are two satellite acceleration sensors mounted in the front of the vehicle to aid in detecting an impact. There is another impact sensing device located inside the ORC. The sensing device provides crash severity discrimination and confirmation of a crash. The ORC monitors the system to determine the system readiness. The ORC contains On-Board Diagnostics (OBD), and will illuminate the AIRBAG warning lamp on the cluster when a fault occurs. The warning indicator is illuminated for six to eight seconds every time the vehicle is started.

The microprocessor in the ORC monitors internal components and the airbag system electrical circuits to determine the system readiness. If the ORC detects a monitored system fault, it sends messages to the instrument cluster over the Controller Area Network (CAN) data bus to turn ON the airbag warning lamp. A decision algorithm in the ORC microprocessor determines when the deceleration rate is severe enough to require airbag system protection. When the appropriate conditions are met, the ORC sends an electrical signal to deploy the frontal airbags. The impact sensing device is an accelerometer that senses deceleration, which provides verification of the severity of an impact. There are two satellite acceleration sensors mounted in the front of the vehicle to aid in detecting an impact. The ORC is calibrated for the specific vehicle, and is only serviced as a unit. The ORC also contains an energy-storage capacitor. The purpose of the capacitor is to provide airbag system protection if the impact has damaged or disconnected the battery. The ORC cannot be repaired or adjusted, and if damaged or faulty, must be replaced.