Crown Victoria V8-4.6L VIN W (2000)
Air Bag Control Module: Description and Operation
The air bag Electronic Crash Sensor (ECS) module performs the following functions:
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signals the inflators to deploy the air bags in the event of a deployable crash.
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monitors the air bag Supplemental Restraint System (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 Lighting Control Module (LCM) to activate a chime if the air bag indicator is not available and another SRS fault exists.
NOTE: The safing sensor is internal to the ECS and is not serviced separately.
The ECS monitors the SRS for possible faults. If a fault is detected while the ignition switch is in the RUN position, the ECS 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 flash the two-digit LFC. The air bag indicator will flash the LFC five
times, then it will remain illuminated for the rest of the key cycle. The ECS will also communicate the current and historical DTCs the DLC, using the
scan tool. If the air bag indicator does not function, and the system detects a fault condition, the ECS will signal the LCM 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 first. After the fault has been
corrected, the next highest priority fault will be displayed.
The ECS includes a backup power supply. This feature provides sufficient backup power to deploy the air bags in the event that the ignition circuit is
damaged in a collision before the safing and air bag sensors close. The backup power supply will deplete its stored energy approximately 1 minute after
the battery ground cable is disconnected.
