Final answer:
The ECU matches intercepted signals with pre-programmed threat data to alert the aircrew of potential threats, enabling them to respond accordingly.
Step-by-step explanation:
Once the Electronic Control Unit (ECU) determines that the intercepted signal matches pre-programmed threat data, an alert is transmitted to the aircrew interfaces. This process is part of an aircraft's defensive systems, where the ECU plays a critical role in threat detection and response. The ECU constantly monitors signals and compares them with a database of known threats. If a match is found, indicating a potential threat, the system alerts the aircrew to take appropriate action, which could include evasive maneuvers or the deployment of countermeasures.