Restraints Control Module (RCM)
The RCM carries out the following functions:
- Deploys the air bag(s) in the event of a deployable crash.
- Activates the safety belt buckle pretensioner and safety belt adaptive load limiting retractor to control tension on the safety belt.
- Monitors the SRS for faults.
- Illuminates the air bag indicator if a fault is detected.
- Communicates through the data link connector (DLC) the on-demand or continuous Diagnostic Trouble Codes (DTCs).
- Signals the instrument cluster module to activate a chime if the air bag indicator is not available and another SRS fault exists.
The RCM monitors the SRS for possible faults. If a fault is detected while the ignition switch is in the ON position, the RCM will illuminate the air bag indicator located in the instrument cluster.
When the ignition is cycled (turned OFF and then ON), the air bag indicator will prove out by lighting for 6 seconds and then off. If a SRS fault exists, the air bag indicator will illuminate and remain illuminated for the rest of the key cycle. The RCM will also communicate the on-demand (current) and continuous (historical) DTCs through the DLC, to the diagnostic tool. If the RCM requests illumination of the air bag indicator and the air bag indicator does not function, the instrument cluster module will automatically activate an audible chime. The chime is a series of 5 sets of 5 tone bursts. If the chime is heard, the SRS and the air bag indicator require repair.
The RCM includes a backup power supply. This feature provides sufficient backup power to deploy the air bags in the event that the ignition circuit is lost or damaged during impact. The backup power supply will deplete its stored energy approximately one minute after the battery ground cable is disconnected.