Abstract: A method of determining the position of a cam phaser determines and stores an adaptively updated base offset corresponding to the phase offset of a camshaft relative to a crankshaft for a reference or default position of a cam phaser. Thereafter, the phaser position is determined relative to the base offset. Individual base offsets are preferably determined for each tooth of a toothed cam wheel, and stored in a non-volatile memory device. During engine operation, the base offsets are subject to diagnostic testing and adaptive updating, and the updated base offsets are stored in the non-volatile memory at engine shut-down.

Abstract: A method of determining the position of a cam phaser determines and stores an adaptively updated base offset corresponding to the phase offset of a camshaft relative to a crankshaft for a reference or default position of a cam phaser. Thereafter, the phaser position is determined relative to the base offset. Individual base offsets are preferably determined for each tooth of a toothed cam wheel, and stored in a non-volatile memory device. During engine operation, the base offsets are subject to diagnostic testing and adaptive updating, and the updated base offsets are stored in the non-volatile memory at engine shut-down.