ENGINE COOLING FAN SPEED CONTROL SYSTEM

摘要

A fan cooling system and method are provided to control fan speed for cooling vehicle motor components while minimizing power consumption by the fan and reducing engine fuel consumption for an engine partially powering the fan. The fan cooling system raises engine coolant temperature of a vehicle in motion to derive a fan speed demand so that fan speed may be reduced. The fan cooling system selects a maximum fan speed demand from one or more fan speed demands to command fan speed based on various sensed inputs, including engine coolant temperatures. The fan cooling system also improves cooling efficiency by incorporating slipheat protection for the fan so as not to overdrive the fan for cooling.