Patent ID: 8739616
Filing Date: 2014-06-03
Classification: F02D,Y02T

Abstract:
1. A method for diagnosing a sensor unit of an internal combustion engine, the method comprising: comparing an output signal of the sensor unit to a setpoint value which is specified independently from the output signal, wherein the setpoint value possesses a periodic characteristic; and analyzing a variation over time of one of (i) a value of the output signal of the sensor unit, and (ii) a variable which is derived from a value variation of the value of the output signal over time with regard to the periodic characteristic; detecting a defect in a sensor unit when the analysis results in a measured value that is outside of a predetermined value range; wherein the periodic characteristic includes at least one of an amplitude and a phase characteristic, and wherein the comparing includes comparing at least one of the amplitude and the phase characteristic of one of the value variation over time and the variable which is derived from the value variation over time to at least one stored value for the setpoint value, wherein the defect in the sensor unit is assigned to an error pattern depending on the result of the comparison of at least one of the amplitude and the phase characteristic of one of the value variation over time and the variable which is derived from the value variation over time with the at least one stored value for the setpoint value.