Mystique V6-153 2.5L DOHC VIN L SFI (1999)
Air Bag Control Module: Description and Operation
This vehicle has a single point sensing system. The diagnostic monitor, crash sensors and safing sensor are incorporated into an electronic air bag control
module mounted centrally in the vehicle. The air bag control module retains full control of the complete air bag system.
The electronic air bag control module is mounted horizontally to the floor pan beneath the floor console, to facilitate impact sensing along the
longitudinal axis. The air bag control module retains full control of the air bag system at all times, providing continual systems checks and maintaining a
full diagnostic function. The air bag control module stores any faults detected during a driving cycle in a non volatile memory, which can be accessed
through the Data Link Connector (DLC) using appropriate test equipment. The air bag control module indicates the presence of a fault by flashing the air
bag warning indicator after the initial prove out sequence. The behavior of the warning indicator depends on the type of fault present.
Air Bag Indicator
If the air bag warning indicator fails, the air bag control module uses the secondary air bag warning indicator. The secondary air bag warning indicator
will only flash if there is a fault present and the primary air bag warning indicator is inoperative.
The air bag control module provides a back up power supply, sufficient to deploy the air bag(s) for a maximum of 150 mS after power loss. The back up
power supply is discharged by the electronic air control module within 60 seconds of the battery ground cable being disconnected.
The air bag control module contains a micro controller to evaluate and process impact data an electronic accelerometer, which measures the actual
acceleration and deceleration along the vehicle's longitudinal axis and an electro-mechanical safing sensor. When both these sensors detect an impact in
excess of a predetermined limit, the deployment sequence will be initiated by the air bag control module to deploy the frontal air bag(s). The two sensors
working together prevent unintentional deployment of the frontal air bag(s).
The air bag warning indicator is located in the instrument cluster. It illuminates for approximately six seconds when the ignition is turned ON and then
will go OFF unless a fault is detected. If a fault is detected the warning indicator will start to flash after another 5 seconds.
