"Mini Air Cooling Fan" various fan control types, control their own characteristics. Big car manufacturers what they need under different circumstances, and thus present a variety of types of control technologies coexist. A typical example is the US General series cars, such as Sail, Buick basic, Picasso Senna too. The integrated cooling fan control system in which the power of the engine control module (PCM) in. Ambient temperature, the air conditioning compressor pressure, coolant temperature, intake air temperature sensor signal is sampled in order to control external power relays to control high and low two fans.