Principles of Operation: Notes

In a frontal collision, the front impact severity sensor detects sudden vehicle deceleration and sends an electrical signal to the Restraints Control Module (RCM). The RCM  uses the information from the front impact severity sensor, safety belt buckle switches and the Occupant Classification System Module (OCSM) to determine deployment. If the RCM  determines that deployment is required, the RCM  sends voltage and current to the air bag module(s) and safety belt pretensioner(s).

In a side collision, the side impact sensor(s) detects sudden vehicle lateral deceleration and sends an electrical signal to the RCM  . The RCM  uses the information from the side impact sensor, safety belt buckle switches and the OCSM  to determine deployment. If the RCM  determines that deployment is required, the RCM  sends voltage and current to the safety canopies, seat side air bag module(s), adaptive load limiter retractors and safety belt pretensioner(s).

The RCM  contains an internal sensor that detects rollover angles of the vehicle. If the RCM  determines that a rollover condition exists and deployment is required, the RCM  sends voltage and current to the safety canopies, safety belt pretensioner(s) and/or adaptive load limiter retractors.

During a frontal or side crash, the RCM  may activate the adaptive load limiter retractors, safety belt pretensioners, seat side air bag (s), one or both stages of the driver/passenger dual-stage air bag based on crash severity and conditions. The fact that the safety belt buckle pretensioners, adaptive load limiter retractors or air bags did not activate for both front seat occupants in a collision does not mean that something is wrong with the system.

The RCM  performs a "self-test" of the complete Supplemental Restraint System (SRS) during each startup. If a SRS  fault exists, the air bag warning indicator will illuminate and remain illuminated for the rest of the ignition cycle until the fault is no longer detected. In addition to the self-test at start up, the RCM  continuously monitors all of its SRS  components and circuitry for correct operation.