Front Door Side Impact Sensor

Front Door Side Impact Sensor

Description






Two pressure type front door side impact sensors (2) are used on this vehicle when it is equipped with the side curtain airbags, one each for the left and right sides of the vehicle. These sensors are mounted remotely from the impact sensor that is internal to the occupant restraint controller. Each side sensor is secured with two screws and is sealed by a resilient gasket (1) to the front door module carrier on the inside of the front door. The sensors are concealed behind the front door trim panel within the passenger compartment.

The right and left front door side impact sensors are identical in construction and calibration. The impact sensor housing has an integral connector receptacle (3), two integral mounting tabs, and an integral hood like water shield (4) that extends through a hole in the front door module carrier into the interior of the door cavity and protects the sensor orifice from contamination. 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 the pressure sensor. The housing cavity is filled with a potting material to seal and protect the internal electronic circuitry and components. A label on the sensor has a directional arrow and the word down imprinted upon it to provide verification of the correct sensor orientation in the vehicle. The side impact sensors are each connected to the vehicle electrical system through a dedicated take out and connector of the front door wire harness.

These pressure type front door side impact sensors cannot be repaired or adjusted and, if damaged or ineffective, they must be replaced.

Operation

The pressure type front door side impact sensors recognize a side impact in the front door area by monitoring changes in pressure within the front door cavity, which manifests itself as a sudden pressure wave as the door collapses during 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 microprocessor in the ORC.

The ORC microprocessor continuously monitors all of the side passive restraint system electrical circuits to determine the system readiness. If the ORC detects a monitored system fault, it sets a diagnostic trouble code and controls the airbag indicator operation accordingly. The impact sensors each 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 current in the sensor plus circuit.

The hard wired circuits between the pressure-type front door side impact sensors and the ORC may be diagnosed using conventional diagnostic tools and procedures. However, conventional diagnostic methods will not prove conclusive in the diagnosis of the impact sensors or the electronic controls or communication between other modules and devices that provide features of the supplemental restraint system. The most reliable, efficient, and accurate means to diagnose the pressure-type front door side impact sensors or the electronic controls and communication related to side impact sensor operation requires the use of a diagnostic scan tool.