Crown Victoria V8-4.6L SOHC VIN 6 (1996)
Air Bag Control Module: Description and Operation
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.
-
writes a Diagnostic Trouble Code (DTC) to the air bag diagnostic monitor's Non-volatile Random Access Memory (NVRAM).
-
turns the air bag indicator lamp on if it detects a concern in the air bag system.
-
after servicing, the diagnostic trouble code may then be cleared from NVRAM.
-
performs system diagnostics which is its main function.
-
DOES NOT DEPLOY THE AIR BAGS IN THE EVENT OF A COLLISION.
-
monitors the system for readiness. Several important features of the air bag diagnostic monitor and its functions within the system. It is necessary
that these key features and functions are well understood.
Air Bag System Functions
-
The air bag diagnostic monitor illuminates the air bag indicator for approximately six seconds when the ignition switch is turned to RUN 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 a any time, then a fault has been detected by the air bag diagnostic monitor.
-
Diagnostic trouble codes if present, will begin flashing within 30 seconds after the ignition switch has been turned to RUN. This is the amount of
time it takes the air bag diagnostic monitor to a tests and verify system faults, if present.
-
Diagnostic trouble codes are displayed as a series of flashes and pauses of he air bag indicator. Diagnostic trouble codes are two-digit numbers.
Example: A DTC 32 is displayed as follows:
flash flash flash - (two second pause) -
flash flash - (five second pause)...
flash flash flash - (two second pause) -
flash flash - (five second pause)...
-
Diagnostic trouble codes re prioritized numerically so that if two or more faults occur at the same time, the diagnostic trouble code with the
highest priority will be displayed.
-
After the DTC is displayed five times, the air bag indicator will illuminate continuously until the ignition switch is cycled.
-
The air bag diagnostic monitor incorporates nonvolatile random access memory (NVRAM) to store diagnostic trouble codes and retain them
indefinitely. The air bag diagnostic monitor will always flash the highest priority diagnostic trouble code stored in NVRAM. Diagnostic trouble
codes may be cleared from the air bag diagnostic monitor after the fault conditions are serviced.
-
The air bag diagnostic monitor distinguishes between hard and intermittent (or repaired) fault conditions:
^
Each diagnostic trouble code number 12 through 45 represents a hard fault (a fault that is still present). Hard diagnostic trouble codes are
higher priority than intermittent diagnostic trouble codes and may not be cleared from NVRAM.
^
Each of these hard diagnostic trouble codes has an equivalent diagnostic trouble code which is the sum of the diagnostic trouble code number
plus 40. This equivalent diagnostic trouble code will indicate that an intermittent condition exists, or that a hard condition has been repaired.
^
Only the intermittent (repaired) diagnostic trouble codes, numbers 52 through 85, may be cleared from the air bag diagnostic monitor.
Example: A Diagnostic Trouble Code 32 indicates that high resistance in the driver side air bag circuit has been, and still is, present. A DTC
72 (32 + 40) indicates that high resistance in the driver side air bag circuit existed at one time, but no longer exists due to an intermittent
condition or a repair made to the circuit.
-
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 55 or any other diagnostic trouble code. The air bag indicator must be
