Abstract: An early cylinder identification method and system using pulsewidth encoding are provided for use in a variable camshaft timing equipped engine. The method includes generating multiple signal pulses, each signal pulse having a unique length and being associated with one of the engine cylinders. The method also includes measuring the length of a signal pulse, and identifying the engine cylinder associated with the signal pulse based on the measured length of the signal pulse. A system includes a specially designed sensor wheel and control logic for performing the method.

Abstract: A method and system are provided for distinguishing a cylinder identification (CID) signal pulse from camshaft timing signal pulses in a variable cam timing (VCT) engine having multiple engine combustion events. The method includes generating multiple signal pulses including a signal pulse which identifies an engine cylinder and a signal pulse for each one of the multiple engine combustion events. The method also includes measuring a first time period between a first signal pulse and a second signal pulse, measuring a second time period between the second signal pulse and a third signal pulse, and determining that the third signal pulse is the cylinder identification signal pulse if a product of the second time period and a scaling factor fails to exceed the first time period. A specially designed VCT/CID signal generator, and an appropriately programmed microprocessor are provided for performing the method.