Circuit/System Description

The pedestrian impact detection system senses and discriminates vehicle impacts and deploys the pedestrian hood hinge actuators in a timely manner to help reduce pedestrian head injuries. The Pedestrian Impact Detection Sensors provides force information to the Inflatable Restraint Sensing and Diagnostic Control Module. The Inflatable Restraint Sensing and Diagnostic Control Module uses force information from the sensor to determine those events when the deployment of the hood hinge actuator is expected. The pedestrian hood actuators deploy only when a valid signal whose energy is capable of triggering deployment of the hood is present. During a frontal pedestrian impact of sufficient force, the Inflatable Restraint Sensing and Diagnostic Control Module will allow current to flow through the deployment loop in order to deploy the hood hinge actuator. The Inflatable Restraint Sensing and Diagnostic Control Module provides a minimum of 1.2 amps and a maximum of 1.95 amps of current for a minimum of 2 ms when an actuator deployment is commanded. The Inflatable Restraint Sensing and Diagnostic Control Module performs continuous diagnostic tests on the deployment loops to check for proper circuit continuity. The Inflatable Restraint Sensing and Diagnostic Control Module sets this DTC in the current ignition cycle when a hood hinge actuator deployment has been commanded. After a deployment, the hood hinge actuators and the Inflatable Restraint Sensing and Diagnostic Control Module need to be replaced.