Impact Sensor: Description and Operation

The sensor:
- Is an electrical switch which reacts to impacts according to direction and force.
- Discriminates between impacts that require air bag inflation and impacts that do not.
- Closes its contacts on an impact that requires air bag inflation, completing the electrical circuit necessary for system operation.

Air Bag Firing Circuit:

The sensors in the vehicle determine if air bag inflation is required in the following manner:
1. During severe frontal deceleration caused by an 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. The safing sensor 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:
- A center cowl primary crash front air bag sensor and bracket at the center cowl top in engine compartment.
- A center radiator primary crash front air bag sensor and bracket at the center front radiator support.
- A safing rear air bag sensor and bracket at the LH kick panel in the passenger compartment.