Mustang Cobra V8-281 4.6L DOHC VIN V MFI (1997)
Air Bag Control Module: Description and Operation
PURPOSE
Performing system diagnostics is the main purpose of the air bag diagnostic monitor.
The air bag diagnostic monitor continually monitors all air bag system components and wiring connections for possible faults when the ignition switch
is in RUN position.
OPERATION
It does not deploy the air bags in the event of a collision. The air bag diagnostic monitor operates in the following manner:
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If the air bag diagnostic monitor detects a fault in the air bag system, a Diagnostic Trouble Code (DTC) will be written to the air bag
diagnostic monitor's Non-Volatile Random Access Memory (NVRAM).
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This DTC will then be displayed on the air bag indicator lamp.
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After servicing, the DTC may then be cleared from NVRAM.
AIR BAG SYSTEM FUNCTIONS
Other important features of the air bag diagnostic monitor and its functions within the system are described below. It is necessary that these key
features and functions are well understood.
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The air bag diagnostic monitor illuminates the air bag indicator for approximately six seconds when the ignition switch is turned to the RUN
position and then turns the air bag indicator Off. This indicates that the air bag indicator is operational. If the air bag indicator does not illuminate
at all, stays On continuously or flashes at any time, then a fault has been detected by the air bag diagnostic monitor.
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Diagnostic trouble codes, if present, will cause the AIR BAG indicator to begin flashing within 30 seconds after the ignition switch has been
turned to the RUN position. This is the amount of time it takes the air bag diagnostic monitor to perform all tests and verify system faults, if
present.
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Diagnostic trouble codes are retrieved using the Rotunda New Generation Star (NGS) tester 007-00500 or equivalent.
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The air bag diagnostic monitor incorporates Nonvolatile Random Access Memory (NVRAM) to store DTCs and retain them indefinitely.
Diagnostic trouble codes may be cleared from the air bag diagnostic monitor after the fault conditions are serviced.
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If a system fault exists and the AIR BAG indicator is not functioning, an audible tone will be heard indicating a need for service. The tone is a
series of five sets of five beeps. This does not indicate a diagnostic trouble code. The AIR BAG indicator must be serviced before diagnostic
trouble codes can be determined.
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WARNING: Under no circumstances substitute another fuse value for the 1oa fuse. Any fuse other than 1oa may cause disarming failure
and may result in danger to the occupants of the vehicle. Do not attempt to replace the 10 a fuse until the air bag system first has been
deactivated (Refer to deactivation procedure for details).
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If a fault exists that makes unwanted air bag deployment possible, the air bag diagnostic monitor will attempt to remove deployment power by
turning On a solid state switch to open the 10 A fuse.
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If the 10 A fuse has successfully been opened by the air bag diagnostic monitor, the air bag diagnostic monitor will not attempt to open it again
until the proper fault has been serviced and cleared. The air bag diagnostic monitor will store both the diagnostic trouble code that caused it to
open the 10 A fuse and the loss of deployment power diagnostic trouble code (DTC B1867). The loss of deployment power diagnostic trouble
code is the highest priority.
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WARNING: The backup power supply energy must be depleted before any air bag component service is performed. To deplete the
backup power supply energy, disconnect the negative battery cable and wait one minute to avoid accidental deployment and possible
personal injury.
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The air bag diagnostic monitor includes an internal backup power supply. This feature provides sufficient backup power to deploy the air bags in
the event that the battery or battery cables are damaged in a collision before the crash sensors are activated. The backup power supply will deplete
its stored energy approximately one minute after the negative battery cable is disconnected.
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The air bag diagnostic monitor incorporates an internal safing sensor. Proper mounting of the air bag diagnostic monitor and bracket assembly is
critical to the function and performance of the air bag system.
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The air bag diagnostic monitor and bracket assembly is non-serviceable and must be replaced as a unit in the event of failure.
