METHOD FOR AUTHORISING UPDATING OF A MAGNETIC SENSOR FOR A COMBUSTION ENGINE WITH IMMUNITY TO MAGNETIC DISTURBANCES

摘要

The invention concerns a method for authorising an updating of a switching threshold of a magnetic field sensor for a motor vehicle combustion engine in order to ensure immunity of the sensor to external magnetic disturbances. The sensor detects magnetic field variations induced by teeth of a target passing close to the sensor, producing a magnetic signal having oscillations, some of which may be due to magnetic disturbances and should not be taken into account for the updating by the sensor of the switching threshold (SC) recalculated according to a detected amplitude of at least two consecutive oscillations of the magnetic field. Updating of the switching threshold is suspended when a frequency of oscillation calculated between the at least two consecutive oscillations is greater than a maximum frequency of oscillation calculated from a predetermined speed of rotation of the motor and the number of teeth on the target.