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 protect vulnerable pedestrians. The discrimination sensor provides discrete force information to the pedestrian impact detection module. The pedestrian impact detection module uses vehicle acceleration information from the safing sensor and force information from the discrimination 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 pedestrian impact detection module will allow current to flow through the deployment loop in order to deploy the hood hinge actuator. The pedestrian impact detection 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 pedestrian impact detection module performs continuous diagnostic tests on the deployment loops to check for proper circuit continuity. The pedestrian impact detection 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 pedestrian impact detection module need to be replaced.