Self-diagnosing pedestrian protection sensor system for a vehicle

A self-diagnosing sensor system for a vehicle, the vehicle having a bumper with fascia material, the sensor system comprising:

• an elongated, deflectable cable disposed in the bumper generally adjacent to the fascia material,
• a tensioning and sensing unit coupled to each end of the cable, each tensioning and sensing unit being fixed to the vehicle and comprising:
• a cable drive member fixed to an associated end of the cable,
• a biasing member acting on the cable drive member so as to bias the cable to a non-deflected, sensing position, and
• a tension sensor constructed and arranged to detect tension of the cable,
• wherein each tension sensor is constructed and arranged to be electrically connected with an ECU such that the ECU can receives signals from the tension sensors regarding tension in the cable, indicative of 1) whether the bumper has been impacted based on deflection of the cable from the sensing position, or 2) whether damage to the cable or a tensioning and sensing unit has occurred.