Safing Sensor: Description and Operation

Air Bag Sensors






The air bag system is designed to operate in frontal or front-angled collisions. The air bags should activate in a crash with severe frontal deceleration, more severe than hitting a parked car of similar size and weight head-on at about 45 km/h (28 mph).

Because the system senses the severity of the crash rather than vehicle speed, some frontal collisions at speeds above 45 km/h (28 mph) may not be severe enough to require air bag inflation.

The air bag sensors determine if air bag inflation is required in the following manner:
1. Upon impact that decelerates the vehicle in the forward direction, both a primary crash sensor and a safing sensor will activate.
2. When a primary and safing sensor are closed at the same time, electrical current will flow igniting the air bags.

The primary sensors measure the crash severity while the safing sensor confirms the crash and is used to prevent inadvertent deployments possibly caused by a malfunction in the primary crash sensor circuits or crash sensors.

Three sensors are mounted in the vehicle. Their locations are as follows:
1. A primary crash sensor at the RH radiator support.
2. A primary crash sensor at the LH radiator support.
3. A safing sensor at the top of the dash panel in the engine compartment.






The safing and at least one of the primary crash sensors must be activated simultaneously to inflate the air bag.