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.
