Impact Sensor
| Refer to COMPONENT INDEX . |
Remote or satellite impact sensors are mounted in four strategic locations of the vehicle. These sensors are mounted remotely from the impact sensor that is internal to the ORC. Sensors at the front of the vehicle provide an additional logic input for use by the ORC to control the front airbags and the seat belt tensioners. Sensors on each side of the vehicle provide an additional logic input for use by the ORC to control the seat airbags and the seat belt tensioners.
Two front impact sensors are used on vehicles equipped with dual front airbags, one on the back of each front lower load beam, below each headlamp assembly. Two side impact sensors are used, one on each side of the vehicle. These acceleration-type sensors are located behind the B-pillar trim of each lower inner B-pillar.
ACCELERATION TYPE
Although the front and side acceleration type impact sensors are similar in appearance and construction, they may not be interchangeable. The front impact sensors may monitor acceleration forces on a different axis than those monitored by the side impact sensors. Each sensor is secured with a single nut to a weld stud in its mounting location.
Each sensor housing has an integral connector receptacle, an integral locator and anti-rotation pin and an integral mounting hole with a metal sleeve to provide crush protection. A cavity in the center of the molded plastic impact sensor housing contains the electronic circuitry of the sensor which includes an electronic communication chip and an electronic acceleration sensor. Potting material fills the cavity and a translucent molded cover is laser welded over the cavity to seal and protect the internal electronic circuitry and components.
The acceleration type impact sensors are electronic accelerometers that sense the rate of vehicle deceleration, which provides verification of the direction and severity of an impact. Each sensor also contains an electronic communication chip that allows the unit to communicate the sensor status as well as sensor fault information to the micro-controller within the ORC.
The ORC micro-controller continuously monitors all of the passive restraint system electrical circuits to determine the system readiness. If the ORC detects a monitored system fault, it sets a DTC and controls the airbag indicator operation accordingly. The impact sensors on each side of the vehicle receive battery current and ground through dedicated left and right sensor plus and minus circuits from the ORC. The impact sensors and the ORC communicate by modulating the voltage in the sensor plus circuit.
The front impact sensors are each connected to the vehicle electrical system through dedicated take outs and connectors of the dash wire harness, while the side impact sensors are connected through dedicated take outs and connectors of the body wire harness.
The acceleration type impact sensors cannot be repaired or adjusted and, if damaged or ineffective, they must be replaced.