Accordingly, a control system for controlling a viscous clutch of a fan is provided. The control system includes a delta speed module that determines one of an over speed condition, an under speed condition, and a steady state condition based on a desired fan speed and an actual fan speed. A mode module determines a mode of the clutch based on the one of the over-speed condition, the under-speed condition, and the steady state condition, wherein the mode is one of a pump in mode, a pump out mode, and a closed loop mode. A valve control module that controls an operational state of the clutch valve based on the mode.