Final answer:
The amber FAULT light indicates a fault in the wing anti-ice system.
Step-by-step explanation:
The amber FAULT light in the WING ANTI ICE pb indicates a fault or malfunction in the wing anti-ice system. This system is used to prevent ice from forming on the wings of an aircraft during flight. If the amber fault light is illuminated, it means that there is an issue with the wing anti-ice system that needs to be addressed.