METHOD FOR ELECTRIC DIAGNOSIS OF AN INTERNAL COMBUSTION ENGINE OXYGEN SENSOR

The invention concerns a method for electric diagnosis of an oxygen sensor of an internal combustion engine functioning on several richness values and in particular on a lean burn, characterised in that it consists in the following steps: monitoring the functioning of the engine and when predetermined functioning conditions are observed in which the richness of the carburetted mixture remains different from the stoichiometry for a sufficient time interval, measuring the voltage level of the signal emitted by said oxygen sensor; comparing this voltage value to a polarisation value and deducing therefrom if said voltage value is substantially equal to the polarisation voltage the existence of a fault in the electric connection of the sensor, or otherwise the absence of fault in the sensor electric connection.