Process for single diagnosis of a nitrogen oxides sensor arranged in the exhaust gas line of an internal combustion engine comprises using a lambda signal characterizing the lambda value of the exhaust gas

摘要

Process for single diagnosis of a NOx sensor arranged in the exhaust gas line of an IC engine comprises determining a lambda signal characterizing the lambda value of the exhaust gas, preferably a wide band, lambda or lambda jump signal; comparing the determined values of the lambda signal with reasonable exhaust gas lambda values during prescribed operating parameters; and forming a NOx sensor diagnosis depending on the comparison results. An Independent claim is also included for a device for single diagnosis of a NOx sensor arranged in the exhaust gas line of an IC engine. Preferred Features: The values of the NOx signal are compared with reasonable values of the NOx concentration during prescribed operating parameters and a further NOx sensor diagnosis is formed depending on the comparison results.