METHOD OF DIAGNOSING THE PRESENCE OF AN EXHAUST AFTER-TREATMENT COMPONENT AND A USE OF THE METHOD FOR VEHICLE ON-BOARD DIAGNOSIS

摘要

A method for diagnosing the presence of an internal combustion engine (10) exhaust aftertreatment component (12) on a vehicle. The exhaust temperature is measured downstream the aftertreatment component (12) continuously over a time period to provide a first temperature signal with fluctuating amplitude. The temperature signal is modified to provide a second modified temperature signal. The first and second temperature signals are compared to detect any significant difference between the signals.