Air Bag Control Module: Description and Operation

Main Sensor




The main sensor is a deceleration detection device which is contained in the MRS control unit. The sensor consists of a spring and weight system which is attached to strain gauges in a Wheatstone bridge circuit. If a change in strain gauge resistance is greater than a preset value, it corresponds to a crash condition of sufficient severity to warrant MRS component deployment. In this case, the processor provides a signal to initiate airbag module and/or seat belt pre-tensioner deployment. Deployment will only be carried out if a confirmation signal that a crash condition is occurring is received by the MRS control unit. Crash condition confirmation is achieved by the simultaneous actuation of the safing sensor.