Navigator 2WD V8-5.4L (2007)
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 restraints control module (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, a new RCM must be installed whether or not the air bags have deployed.In addition,
make sure the area of the RCM mounting is restored to its original condition.Failure to follow these instructions may increase the risk of
personal injury or death in a crash.
CAUTION: Prior to removal of the 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 Information Bus (Module Communications Network).
NOTE:
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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 RCM DTCs.
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When installing a new restraints control module (RCM), always make sure the correct RCM is being installed.RCMs are not interchangeable
between vehicles or vehicle lines.If an incorrect RCM is installed, erroneous DTCs and incorrect diagnosis will result.
The restraints control module (RCM) 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 warning indicator if a fault is detected.
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communicates through the data link connector (DLC) the current or historical diagnostic trouble codes (DTCs).
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 request illumination of
the air bag warning indicator located in the instrument cluster.
When the ignition switch is cycled (turned OFF and then ON), the air bag warning indicator will prove out by lighting for 6 seconds and then turn off.If
a SRS fault exists, the air bag warning 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 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 the battery ground cable is
disconnected.
A new RCM installed in a vehicle will flash lamp fault code (LFC) 54 until programmable module installation (PMI) has been carried out on the RCM.If
a LFC is present after completing PMI, a fault is present in the SRS and on-demand DTCs must be retrieved and diagnosed.
