Patent ID: 7661297

Claim:
A method for providing an improved phase signal of an active phase sensor of a camshaft of an internal combustion engine, comprising: immediately after switching on at least one of the phase sensor and the internal combustion engine, scanning angle marks of a first signal-generating wheel that is connected torsionally fixed to the camshaft, using the phase sensor; performing a calibration procedure of the phase sensor during the switching on of the internal combustion engine; and scanning angle marks of a second signal-generating wheel that is connected torsionally fixed to a crankshaft of the internal combustion engine, using a crankshaft sensor; wherein: a) after an initial switching on of the phase sensor: a. 1) ascertaining a start-up signal position of the phase signal during the calibration procedure of the phase sensor, based on a crankshaft signal over a plurality of angle marks of the first signal-generating wheel connected to the camshaft, wherein during the calibration procedure of the phase sensor, the phase signal is corrected stepwise by adjustment values until a normal signal position is achieved; a.2) ascertaining the normal signal position of the phase signal based on the crankshaft signal after the switching on of the internal combustion engine and after a concluded calibration procedure of the phase sensor; a.3) determining angle errors from a difference between the start-up signal position and the normal signal position; and a.4) storing in a nonvolatile memory correcting values that are based on the angle errors; and b) during a subsequent renewed switching on of at least one of the phase sensor and the internal combustion engine, correcting the phase signal during the calibration procedure by the correcting values, whereby, after the renewed switching on of the phase sensor, an improved phase signal is provided.