Abstract: A default engine control method for an internal combustion engine recovers from the loss of a high-resolution engine position signal by calculating a high resolution pulse period based on a recognized pattern of a low resolution engine position signal. Interrupts for signaling the execution of cycle-related control algorithms are scheduled in time based on the calculated pulse period, and pulse period errors due to changing engine speed are periodically corrected based on the timing of subsequent transitions in the low resolution position signal relative to the scheduled interrupts.

Abstract: A method and apparatus for the precombustion identification of a cylinder undergoing compression in an internal combustion engine is disclosed. An electrode gap (e.g., preferably a spark plug) is disposed within a cylinder of an internal combustion engine. The electrode gap is provided with a voltage differential from a power supply through a circuit (preferably an RC circuit). The engine is cranked, and the voltage differential across the electrode gap is monitored during the cranking of the engine. With appropriate choices of the voltage differential across the electrode gap, the resistance R of the circuit, and the capacitance C of the circuit, voltage pulses are produced across the electrode gap during such time when the cylinder is not undergoing a compression stroke. Such voltage pulses are suppressed when the cylinder is in fact undergoing a compression stroke due to a rise in the breakdown voltage across the electrode gap, in accordance with Paschen's Law.