Patent ID: 7874285

Claim:
A method for monitoring an exhaust gas probe located in an exhaust gas duct of an internal combustion engine, comprising: modulating a setpoint value of an air/fuel ratio using a forced excitation signal during a normal operation of the internal combustion engine; allocating either a true or false value to a suspicion marker for an asymmetric ageing of the exhaust gas probe as a function of a trim controller diagnosis; if the value of the suspicion marker is “true”, triggering a monitoring operation for monitoring the exhaust gas probe, including: in response to triggering the monitoring operation for monitoring the exhaust gas probe, increasing an amplitude of the forced excitation signal as compared with the forced excitation signal used during the normal operation of the internal combustion engine; performing a dynamic diagnosis based at least on the increased amplitude forced excitation signal and a measuring signal of the exhaust gas probe; and detecting the exhaust gas probe as being either asymmetrically aged or non-asymmetrically aged based on the results of the dynamic diagnosis.