A method for determining the angular position of an engine by a crankshaft sensor, having the following steps: production by the crankshaft sensor of a signal exhibiting a “revolution” event, determination of the revolution out of two revolutions, since a crankshaft makes two revolutions per engine cycle for a four-stroke engine, for each “no tooth” event potentially produced, a change in the direction of rotation of the engine is suspected, and an analysis step is performed which comprises: if, during an inverse window, a further “no tooth” event is produced, the change in direction of rotation is confirmed.