Exhaust gas treatment device diagnosis method for internal combustion engine, has determining diagnosis parameter, comparing parameter with threshold value and providing error signal when parameter exceeds threshold value

摘要

The method involves measuring an exhaust temperature measure upstream of an exhaust gas treatment device (15). Another exhaust temperature measure is estimated based on a model of a catalytic support reaction. A diagnosis parameter is determined from the estimated and measured temperature measure. The diagnosis parameter is compared with a threshold value, and an error signal is provided when the parameter exceeds the threshold value. An independent claim is also included for a device for diagnosis of an exhaust gas treatment device in an exhaust area of an internal combustion engine.