System and method for prioritising tasks

The invention involves a system and method of improving the control quality of a vehicle engine having a rotatable and positionable crankshaft (14) by prioritising tasks to be performed by a microprocessor (18) pre-programmed with an inventory of foreground and background engine tasks affecting the efficiency and performance of the vehicle. The invention reduces chronometric load of an operating system of a powertrain control module. The invention includes sensing the speed of rotation of the crankshaft to provide a first, second, or third signal indicative of respective low, medium, or high crankshaft speeds, sensing the position of the crankshaft to provide a fourth signal of the crankshaft position, and processing these signals. The foreground tasks are selected for execution, if the fourth signal is received indicating the crankshaft is at a predetermined position. A first set of the foreground tasks are selected for execution in a first manner, if the third signal is received to indicate a low crankshaft speed. A second set of the foreground tasks are selected for execution in a second manner, if the second signal is received to indicate a medium crankshaft speed. A third set of the foreground tasks are selected for execution in a third manner, if the first signal is received to indicate a high crankshaft speed.