System Operation
Supplemental Restraint System (SRS)
System Operation
System Diagram - Supplemental Restraint System (SRS)
Network Message Chart - Supplemental Restraint System (SRS)
Module Network Input Messages - RCM (Restraints Control Module)
System Diagram - Occupant Classification System (OCS)
Network Message Chart - Occupant Classification System (OCS)
Module Network Input Messages - OCSM (Occupant Classification System Module)
Supplemental Restraint System (SRS)
The SRS (Supplemental Restraint System) is controlled by the RCM (Restraints Control Module), which continually monitors various inputs. When these inputs indicate a frontal or side crash, the RCM (Restraints Control Module) may deploy some components, based upon the severity of the crash and the sensor inputs. REFER to System Diagram - Supplemental Restraint System (SRS) to view the SRS (Supplemental Restraint System) inputs and outputs.
Although some deployable devices may not have activated for all occupants during a crash, it does not mean that something is wrong with the SRS (Supplemental Restraint System).
The RCM (Restraints Control Module) performs a self-test of the complete SRS (Supplemental Restraint System) during each startup. During normal operation, the IPC (Instrument Panel Cluster) illuminates the air bag warning indicator continuously for 6 seconds. If the SRS (Supplemental Restraint System) is free of faults, the air bag warning indicator turns off and remains off. If a SRS (Supplemental Restraint System) fault exists, the air bag warning indicator illuminates and remains illuminated for the rest of the ignition cycle. The RCM (Restraints Control Module) communicates to the IPC (Instrument Panel Cluster) via the HS-CAN (High Speed Controller Area Network). The IPC (Instrument Panel Cluster) illuminates the air bag warning indicator based on messaging from the RCM (Restraints Control Module) or if there is no communication between the RCM (Restraints Control Module) and IPC (Instrument Panel Cluster). In addition to the self-test at start up, the RCM (Restraints Control Module) continuously monitors all of its SRS (Supplemental Restraint System) components and circuitry for correct operation.
Air Bag Module Second Stage Deployment Check
The driver and passenger front air bags each have 2 deployment stages. After an air bag module deployment, it is possible that stage 1 has deployed and stage 2 has not. If a front air bag module has deployed, the front air bag module must be remotely deployed using the appropriate air bag disposal procedure. For information on driver air bag module and/or passenger air bag module remote deployment, REFER to Pyrotechnic Device Disposal .
Air Bag Warning Indicator
The air bag warning indicator:
- is located in the IPC (Instrument Panel Cluster) and proves out by lighting for 6 seconds and then turning off.
- flashes and/or illuminates based on the message that the IPC (Instrument Panel Cluster) receives from the RCM (Restraints Control Module).
- illuminates if the IPC (Instrument Panel Cluster) does not receive a message from the RCM (Restraints Control Module).
Event Notification Signal
The purpose of the event notification feature is to provide other vehicle subsystems with information pertaining to restraint system deployment or fuel cutoff status. Signal communication between the RCM (Restraints Control Module) and fuel pump control module allows the PCM (Powertrain Control Module) to initiate fuel cut-off to disable the fuel system in the event of a crash.
OCS (Occupant Classification System)
The OCS (Occupant Classification System) is found only on the front passenger seat. The OCS (Occupant Classification System) classifies the size of the front passenger seat occupant and provides this information to the RCM (Restraints Control Module). The RCM (Restraints Control Module) uses this information (and other inputs) in determining the deployment strategy of the passenger air bag, adaptive load limiter, and passenger seat side air bag and pretensioners. The OCS (Occupant Classification System) is comprised of:
- a silicone gel-filled bladder mounted between the seat cushion foam and seat pan
- an OCSM (Occupant Classification System Module) with an integrated pressure sensor, attached to the seat frame
- a BTS (Belt Tension Sensor), which is hard-wired to the OCSM (Occupant Classification System Module)
Pressure is applied to the OCS (Occupant Classification System) bladder when weight of any occupant or object in the front passenger seat is present. The pressure is then transferred through a tube and sensed by the OCS (Occupant Classification System) pressure sensor within the OCSM (Occupant Classification System Module). The OCSM (Occupant Classification System Module) and pressure sensor is mounted to a bracket underneath the seat cushion pan and is serviced as a kit with the seat cushion and heater mat (if equipped). The OCSM (Occupant Classification System Module) sends information concerning the weight of any occupant or object on the front passenger seat to the RCM (Restraints Control Module) via the HS-CAN (High Speed Controller Area Network). The RCM (Restraints Control Module) uses this information when determining if the passenger air bag module needs to be deployed in the event of a crash.
The OCS (Occupant Classification System) is also used for operation of the passenger Belt-Minder(R). For information on the passenger Belt-Minder(R) feature, REFER to Belt-Minder(R) . To deactivate or reactivate the passenger Belt-Minder(R) feature, REFER to Belt-Minder Deactivating and Activating or the Owner's Literature.
PAD (Passenger Air Bag Deactivation) Indicator
The RCM (Restraints Control Module) controls the state of the PAD (Passenger Air Bag Deactivation) indicator via the HS-CAN (High Speed Controller Area Network) and I-CAN (Infotainment Controller Area Network). The PAD (Passenger Air Bag Deactivation) indicator state is based on information that the OCS (Occupant Classification System) provides to the RCM (Restraints Control Module). When the passenger air bag is activated, the PAD (Passenger Air Bag Deactivation) displays ON. If the RCM (Restraints Control Module) has deactivated the passenger air bag, the PAD (Passenger Air Bag Deactivation) indicator displays OFF.
The RCM (Restraints Control Module) briefly activates the PAD (Passenger Air Bag Deactivation) indicator to prove out the indicator function and verify proper functional operation of the PAD (Passenger Air Bag Deactivation) indicator to the front occupants.
The following table indicates the passenger air bag and PAD (Passenger Air Bag Deactivation) indicator status based on the size of the front passenger occupant.
Inflatable Safety Belts (if equipped)
REFER to System Operation .
Secondary Air Bag Warning (Chime)
The secondary air bag warning chime is an audible chime located in and controlled by the IPC (Instrument Panel Cluster). If a fault is detected with the air bag warning indicator, a DTC (Diagnostic Trouble Code) is stored in memory of the IPC (Instrument Panel Cluster). Upon receiving the message from the RCM (Restraints Control Module) that a SRS (Supplemental Restraint System) fault has been detected, the IPC (Instrument Panel Cluster) sounds the secondary air bag warning chime in a pattern of 5 sets of 5 beeps.
SOS Post-Crash Alert System(TM)
The SOS Post-Crash Alert System(TM) is a system that is controlled by the BCM (Body Control Module) but initiated by the RCM (Restraints Control Module).
When a deployment event occurs, the RCM (Restraints Control Module) sends a message on the HS-CAN (High Speed Controller Area Network) to the BCM (Body Control Module). The BCM (Body Control Module) flashes the turn signal lamps and sound the horn until it is turned off. For information about the SOS Post-Crash Alert System(TM) , REFER to Post Crash Alert Function .