Abstract: A system for controlling engine crankshaft deceleration in an internal combustion engine is operable to determine whether the engine is operating with low inertia, to monitor an operational status of an engine retarding device configured to produce an engine retarding torque for decreasing rotational speed of the engine crankshaft, and to limit the retarding torque produced by the engine retarding device if the engine retarding device is operational and if the engine is operating with low inertia.

Abstract: An engine cooling fan control system includes a vehicle speed sensor, a pressure sensor for sensing the pressure of refrigerant provided to a refrigerant condenser forming part of the vehicle air conditioning system and a controller responsive to the vehicle speed and refrigerant pressure signals to operate an engine cooling fan. The engine cooling fan is activated continuously while vehicle speed is below a first speed threshold if the refrigerant pressure exceeds a first pressure. While the vehicle speed is above the first speed threshold, but below a second speed threshold, the engine cooling fan is activated for a predetermined duration if the refrigerant pressure is above the first pressure. Finally, while the vehicle speed is above the second speed threshold, the engine cooling fan is activated in response to the refrigerant pressure exceeding the first pressure and deactivated in response to the refrigerant pressure falling below a second lower pressure.

Abstract: The disclosure illustrates a cooling system for a turbocharged diesel engine having an aftercooler and an oil cooler. The cooling system is defined by two flow loops, one for the engine and the other for cooling purposes. An engine driven pump circulates a coolant through the engine block and cylinder heads. The pump also circulates coolant through the cooling loop which includes the engine oil cooler immediately upstream of a radiator and bypass line. The aftercooler is downstream of the radiator and bypass line. Placement of the oil cooler ahead of the radiator and bypass line produces a higher temperature potential which permits a reduction in radiator size in addition to other benefits. A flow control logic system embodied in a dual thermostat arrangement ahead of the radiator and bypass line minimizes mixing of bypass flow with radiator flow and reduces radiator flow rates to permit low aftercooler temperatures that hithertofore have not been achievable.