Synchronisation method robust to engine stalling

A method implemented by a processing unit (21) for synchronizing an internal combustion engine (M) equipped with at least one camshaft (91) on which a target (1) is mounted, the target formed as a toothed wheel comprising a plurality of teeth, the internal combustion engine (M) also equipped with a position sensor (2) that senses a position of the camshaft, the position sensor (2) configured to detect an edge of each tooth of the teeth of the target, the processing unit (21) configured to process data generated by the position sensor (20) of the edges of the teeth detected by the position sensor,

• the synchronization method comprising, for each detection of one of the edges of the target successively detected by the position sensor (2) and each being of a type of one of a rising edge and a falling edge, carrying out steps of:
• receiving data from the position sensor (20) of a detected edge;
• computing (110) a time signature of the detected edge;
• comparing (120) the computed time signature of the detected edge with a set of theoretical time signatures of edges of the target of a same type of one of a rising edge and a falling edge as that of the detected edge, a result of the comparing step depending on one of a first tolerance and a reduced second tolerance that is lower than the first tolerance, wherein the comparing step applies the first tolerance when a speed of the engine is higher than a predetermined threshold, and the comparing step applies the reduced second tolerance when the engine speed drops below said predetermined threshold;
• and
• generating one of a synchronization signal and a synchronization fault signal as a function of the result of the comparing step.