Abstract: Various control strategies and techniques for controlling a variable speed fan in an internal combustion engine are provided. The various control techniques improve fuel economy by operating the fan at a speed sufficient to cool the engine, while avoiding unnecessarily higher speeds that result in poor fuel economy. Further, the fan may be completely disabled at cold start up to avoid over cooling, particularly in an engine using a charge air cooling system.

Abstract: Various control strategies and techniques for controlling a variable speed fan in an internal combustion engine are provided. The various control techniques improve fuel economy by operating the fan at a speed sufficient to cool the engine, while avoiding unnecessarily higher speeds that result in poor fuel economy. Further, the fan may be completely disabled at cold start up to avoid over cooling, particularly in an engine using a charge air cooling system.

Abstract: A method of controlling an internal combustion engine having a variable speed fan driven by a torque multiplying fan driver includes controlling the variable speed fan with closed loop control based on fan speed.

Abstract: A method of controlling an internal combustion engine includes determining an exhaust gas recirculation (EGR) command signal based on at least one engine condition, and determining a variable geometry turbocharger (VGT) command signal based on at least one engine condition and at least partially based on the EGR command signal. Advantageously, the EGR system and VGT system may be continuously and simultaneously controlled, taking into account the effects of each system on the other, to provide improved and more precise control over engine air flow. In an alternative embodiment, an engine may be controlled with a feedback control system where engine intake chemical composition is the feedback variable.

Abstract: A method of controlling an internal combustion engine having a variable speed fan includes controlling the variable speed fan with closed loop control based on fan motor hydraulic pressure. A reference fan pressure is based on an applied fan request signal. The actual fan motor pressure is monitored, and an error signal is determined by comparing the reference fan pressure to the actual fan pressure. The fan is driven based on the error signal.