Final answer:
In normal braking situations, modulator valves within an ABS system are not active. They are designed to prevent wheel lock-up during emergency stops, not during routine braking.
Step-by-step explanation:
The question refers to the operation of modulator valves during normal braking applications. During normal braking, the modulator valves are not active. Modulator valves, which are part of an Anti-lock Braking System (ABS), are designed to regulate brake pressure to prevent wheel lock-up during an emergency stopping situation. However, during normal braking where there is no risk of the wheels locking, these valves are not activated and the brakes function without ABS intervention. This allows the vehicle to maintain stability and control when braking under usual conditions.