Patent ID: 6245205
Filing Date: 2001-06-12
Classification: F02D

Abstract:
A diagnostic arrangement for a potentiometric, electrical exhaust-gas probe for the control of combustion processes with a periodic change of the composition of the combusting air/fuel mixture between oxygen deficiency and oxygen excess, said exhaust-gas probe being heated by an electric heater and outputting a probe signal when the exhaust-gas probe operates without fault which changes between a first region of high signal values (oxygen deficiency) and a second region of low signal values (oxygen excess) with said first region of high signal values and said second region of low signal values being separated by a third region of values; the diagnostic arrangement comprising:means for determining the occurrence of a sensor fault when the following conditions are present:(a) said probe signal lies within said third region at the start and at the end of a pregiven longest duration; and,(b) said probe signal has remained within said third region during said pregiven longest duration except for a possible pregiven temporary duration when said probe signal leaves the third region accompanied by a change in the heater current.