The crash sensors are located in the front of the vehicle on either side of the front radiator support. In the event of a head-on impact (or at least a 3 / 4 frontal impact, the sensing mass inside the sensor breaks away from the bias magnet. The sensor mass rolls along a cylinder toward two electrical contacts, if the deceleration is sufficient, the sensing mass will bridge the contacts and complete the primary deployment circuit to the air bag module.
The mounting and orientation of the sensors is vital to system operation. The sensors should be inspected by a qualified individual after any impact where the sensors could have been damaged. If any structural damage is evident, the area must be repaired to its original condition, otherwise the sensor orientation could be compromised. If the sensor(s) have received damage, they must be replaced.
The safing sensor is located behind the kick panel on the passenger side, below the instrument panel. The safing sensor operates identical to the crash sensor, except for the calibration. This is accomplished using a slightly weaker bias magnet. If the safing sensor contacts close simultaneously with the crash sensor, the air bag(s) will be deployed.
The safing sensor is essentially a safety for the air bag system. It protects the bag(s) from deploying due to an electrical short. The safing sensor is used to verify the force of a collision and complete the air bag(s) deployment. The sensor is located inside the passenger compartment so that a forceful enough impact could be detected, and a false signal from the crash sensor would not deploy the air bag(s) at an inappropriate time.