Mountaineer AWD V6-4.0L VIN K Flex Fuel (2003)
Air Bag Control Module: Description and Operation
RESTRAINTS CONTROL MODULE (RCM)
WARNING:
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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 these instructions may result in the inadvertent deployment of the safety
canopy and risk of personal injury.
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The RCM orientation is critical for correct system operation. If a vehicle equipped with an air bag supplemental restraint system (SRS)
has been involved in a collision in which the center tunnel area has been damaged, inspect the mounting and bracket for deformation. If
damaged, the RCM must be replaced whether or not the air bags have deployed. In addition, make sure the area of the RCM mounting is
restored to its original condition.
N0TE: 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 restraints control module carries out the following functions:
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deploys the air bag(s) in the event of a deployable crash.
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activates the safety belt buckle pretensioners to remove slack from the safety belt.
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monitors the SRS for faults.
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illuminates the air bag indicator if a fault is detected.
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flashes the air bag indicator to indicate the lamp fault code (LFC) detected.
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communicates through the data link connector (DLC) the current or historical Diagnostic Trouble Codes (DTCs).
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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 facts. 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 six seconds and then off for two seconds.
After the prove out, the air bag indicator will then flash the two-digit LFC. If a SRS fault exists, the air bag indicator will flash the LFC five times,
then it will remain illuminated for the rest of the key cycle. The RCM will also communicate the current and historical DTCs through the DLC, to
the scan tool. If the air bag indicator does not function, and the system detects a fault condition, the RCM will signal the instrument cluster module
to activate an audible chime. The chime is a series of five sets of five tone bursts. If the chime is heard, the SRS and the air bag indicator require
repair.
LFCs are prioritized. If two or more faults occur at the same time, the fault having the highest priority will be displayed. 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 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.
