Patent ID: 9068937
Filing Date: 2015-06-30
Classification: F01N,G01N

Abstract:
1. A method for testing an exhaust gas sensor having a first chamber, a second chamber, a first diffusion barrier separating the first and second chambers, and a second diffusion barrier forming a gas inlet of the first chamber, the first chamber having first main pump electrode, the second chamber having a measuring electrode and an auxiliary pump electrode, and a second main pump electrode and a reference electrode being disposed outside of the first and second chambers, said method comprising: sensing a first voltage as a predefined voltage between the auxiliary pump electrode and the reference electrode; determining a set point diagnostic value as a function of the sensed first voltage multiplied by a predefined factor and adding a predefined shift value to the resulting value, wherein the predefined shift value is determined as a function of a calibration of the exhaust gas sensor; sensing a measuring current between the measuring electrode and the second main pump electrode, the measuring current being set as a pump current by adjusting a second voltage between the measuring electrode and the reference electrode to the predefined voltage, and determining an actual diagnostic value as a function of the sensed measuring current; and detecting a fault in the exhaust gas sensor as a function of the set point diagnostic value and the actual diagnostic value.