What component controls the speed of the variable speed coolant pump?

The component responsible for controlling the speed of the variable speed coolant pump is the viscous clutch. A viscous clutch operates by using a fluid-filled chamber that engages and disengages based on temperature differences between the engine coolant and the air, which allows it to adjust the pump's speed more efficiently.

This adaptability is crucial for managing the engine's cooling demands in a way that aligns with varying operational conditions. When higher cooling is needed, the viscous clutch engages more and allows the pump to run at a higher speed, thereby improving cooling performance when the engine is under stress. Conversely, when less cooling is required, the viscous clutch disengages, allowing the pump to slow down, which can enhance fuel efficiency and reduce unnecessary wear on engine components.

Other components listed may be involved in different aspects of the engine's operation but do not specifically control the speed of the variable speed coolant pump like the viscous clutch does.