Restraints Control Module (RCM)

WARNING: This page is about a different car, the 2009 Mercury Grand Marquis and 2009 Ford Crown Victoria. However, it is still accessible from the selected car via links, so may be relevant.

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.

WARNING: Always tighten the fasteners of the restraints control module (RCM) and impact sensor (if equipped) to the specified torque. Failure to do so may result in incorrect restraint system operation, which increases the risk of personal injury or death in a crash.

NOTE: When installing a new Restraints Control Module (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:

Signals the inflators to deploy the air bags in the event of a deployable crash.
Activates the steering column squib to help reduce the force needed to collapse the steering column.
Activates the safety belt retractor pretensioners to remove slack from the safety belt.
Monitors the air bag Supplemental Restraint System (SRS) for faults.
Illuminates the air bag warning indicator if a fault is detected.
Receives information from the front and side impact sensors.
Sends safety belt buckle status to the Instrument Cluster (IC) module for safety belt indicator and Belt-Minder®.
Flashes the air bag warning indicator to indicate the Lamp Fault Code (LFC) detected.
Communicates with the Occupant Classification System Module (OCSM) on a dedicated High Speed Controller Area Network (HS-CAN).
Signals the IC module to activate a chime if a fault is detected.
Communicates through the Data Link Connector (DLC) the current or historical DTCs.
Contains an internal sensor which is not serviced separately.

The RCM monitors the SRS for possible faults. If a fault is detected while the ignition is in the ON position, the RCM will illuminate the air bag warning indicator located in the IC and signal the IC module to activate the chime.

The chime is a series of 5 sets of 5-tone bursts. If the chime is heard and/or the air bag warning indicator is illuminated, the SRS and the air bag warning indicator require repair. When the ignition is cycled (turned off and then on), the air bag warning indicator will remain lit for 6 seconds and then go out. If a SRS fault exists, the air bag warning indicator will then flash the 2-digit LFC. The air bag warning indicator will flash the LFC 5 times, then it will remain illuminated for the rest of the ignition cycle. The RCM will also communicate the current and historical DTCs through the DLC, using the scan tool.

LFCs are prioritized. If 2 or more faults occur at the same time, the fault having the highest priority will be displayed first. After that fault has been corrected, the next highest priority fault will be displayed.

The RCM includes a backup power supply. This feature provides sufficient backup power to deploy the SRS components in the event that the ignition circuit is damaged in a collision before air bag deployment is activated. The backup power supply will deplete its stored energy approximately one minute after power and/or ground has been removed from the RCM.