System Description

System Description

The air bag system is designed to provide increased driver protection if the vehicle is involved in a front-end collision. The system is most effective when used in conjunction with the seat belt system, but it will operate and provide a reduced measure of protection even without seat belts being used.

System Components

� Warning lamp(s) (in the instrument panel)

� Front impact sensors

� SRS Diagnostic Module (SDM) (under the rear console assembly)

� Sensor wiring harness

� Steering wheel

� Air Bag Module (in the center of the steering wheel)

� Clockspring and wiring harness (in the steering column)

System Operation

Whenever the ignition key is turned to the RUN or START position, the SRS warning lamp on the instrument cluster lights and stays lit for 6 to 8 seconds, then goes off. This means that the SRS diagnostic module (SDM) has checked the system and found it to be free of discernible malfunctions.

Use the test procedures in this section to find the cause of any customer complaint regarding the AIR BAG warning lamp, such as:

- warning lamp does not come on at all

- warning lamp stays on

- warning lamp flashes or blinks

The deceleration resulting from the impact of a front-end collision causes the switch inside of the SDM safing sensor to be thrown forward to a closed position. As the front end of the vehicle begins to crush from impact, one or both front sensors are also closed. As soon as one front sensor and the safing sensor are closed, an electrical charge is sent to the Air Bag Module. This causes the inflator to be actuated, which produces a quantity of nitrogen gas, thus deploying the air bag. The total time from the closure of the switches to deployment and deflation of the air bag is 1/10th of a second