Method for synchronising an internal combustion engine

A method for synchronizing an internal combustion engine comprising at least one cylinder, at least one piston movable in the at least one cylinder and driving a crankshaft cooperating with a camshaft, said camshaft cooperating with a known target of the camshaft having a number of cam edges x, and a camshaft sensor generating a camshaft signal as a function of the number of cam edges x, said method comprising:

• a) a first step of acquiring, by the camshaft sensor, signals corresponding to at least five cam edges x,
• b) a second step of determining the value, from the camshaft signal, of a first, second and third actual ratio (N1, N2, N3) for a given cam edge x,
• c) a third step of establishing, for each actual ratio value (N1, N2, N3) obtained in the second step, a list of possible cam edges x by comparing the values of the first, second and third actual ratios (N1, N2, N3), respectively, with a tolerance window corresponding to a value of a first, second or third theoretical ratio (T1, T2, T3) for a given cam edge x, each weighted by a tolerance factor k, and
• d) a fourth step of determining the cam edge x seen by the camshaft sensor, the cam edge actually seen by the sensor corresponding to the cam edge x common to the three lists established in the third step.