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Home >> Ford >> 2009 >> Flex Limited, FWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 1355 (Supplemental Inflatable Restraint System) >> Diagnostic Tests >> Air Bag and Safety Belt Pretensioner Supplemental Restraint System (SRS) >> Principles of Operation >> Restraints Control Module (RCM)

Restraints Control Module (RCM)

WARNING: This page is about a different car, the 2008 Mercury Sable, 2008 Ford Taurus X, and 2008 Ford Taurus. However, it is still accessible from the selected car via links, so may be relevant.
WARNING: Do not handle, move or change the original horizontal mounting position of the restraints control module (RCM) while the RCM is connected and the ignition switch is ON. Failure to follow this instruction may result in the accidental deployment of the safety canopy and cause serious personal injury or death.
WARNING: If a vehicle has been in a crash, inspect the restraints control module (RCM) and the impact sensor (if equipped) mounting areas for deformation. If damaged, restore the mounting areas to the original production configuration. A new RCM and sensors must be installed whether or not the air bags have deployed. Failure to follow these instructions may result in serious personal injury or death in a crash.
NOTE: Prior to removal of the restraints control module (RCM) module, it is necessary to upload module configuration information to the scan tool. This information needs to be downloaded into the new RCM module once installed. Refer to MODULE CONFIGURATION article.
NOTE: When a new PCM is installed, the air bag warning indicator will illuminate when the ignition switch is ON. The warning indicator will remain on until PCM configuration is restored. Clear restraints control module (RCM) DTCs.
NOTE: When installing a new RCM, always make sure the correct RCM is being installed. If an incorrect RCM is installed, erroneous DTCs will result.

The RCM carries out the following functions:

The RCM monitors the SRS for possible faults. If an SRS fault exists, the RCM sends a message to instrument cluster module to flash a coded sequence which is called a LFC on the air bag warning indicator.

When the ignition is cycled (turned OFF and then ON), the instrument cluster will prove out the air bag warning indicator by lighting for 6 seconds and then turn off. If a current SRS fault exists, the RCM requests illumination of the air bag warning indicator and will 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 scan tool. If the RCM requests illumination of the air bag warning indicator and the air bag warning 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 warning 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 power and/or ground has been removed from the RCM.