When Monitored
WARNING: This page is about a different car, the 2015 Fiat 500. However, it is still accessible from the selected car via links, so may be relevant.
With the ignition on, the Front Left Impact Sensor (Early Crash Sensor) is equipped with on board diagnostics to monitor the sensor's internal circuits. If a problem is identified, the sensor sends the Front Right Impact Sensor Internal message to the Occupant Restraint Controller (ORC).