Which component is responsible for detecting pressurization faults?

The pressurization controllers are specifically designed to manage and monitor the aircraft's pressurization system. Their primary function includes detecting any faults or anomalies that may arise within this system. They continuously assess parameters associated with cabin pressure, ensuring that they remain within the operational limits. When a deviation or fault is detected, the pressurization controllers can trigger alerts and initiate corrective actions to maintain safety.

The other components listed perform different functions and do not directly monitor for pressurization faults. The MODE SEL switch, for instance, is used to select different operational modes but does not have a role in monitoring pressurization conditions. The FMGC (Flight Management and Guidance Computer) focuses on the overall management of flight data and navigation but does not handle pressurization alone. The safety valve serves to prevent over-pressurization by venting excess pressure rather than detecting faults in the pressurization system itself. Hence, the pressurization controllers are the correct answer for this question as they play a crucial role in ensuring the cabin pressure is maintained and monitored effectively.