Reagent material-dosing device's part diagnosis method for motor vehicle, involves detecting sensor signal in exhaust duct, and providing error signal during rising of sensor signal

摘要

The method involves detecting a sensor signal (s-Mes-nK) in an exhaust duct downstream to a selective catalytic reduction (SCR) catalyzer (16), which reflects both a measure for nitrogen oxide concentration (NOx-nK) and a measure for a reagent material slack (Rea-Spf) or a slack of decomposition products of a reagent material downstream to the catalyzer. Dosing rate of the reagent material is increased based on the sensor signal, and the dosing rate of the reagent material is decreased during rising of sensor signal. An error signal (s-Feh) is provided during the rising of the sensor signal. Independent claims are also included for the following: (1) a device for diagnosing a part of a reagent material-dosing device of a motor vehicle (2) a computer program comprising a set of instructions for performing a method for diagnosing a part of a reagent material-dosing device of a motor vehicle (3) a computer program product comprising a set of instructions for performing a method for diagnosing a part of a reagent material-dosing device of a motor vehicle.