Patent ID: 8281652

Claim:
A method of testing the functionality of an oxidation catalytic converter of an internal combustion engine of a motor vehicle, which comprises the following steps: (a) checking whether the motor vehicle is at a standstill; (b) checking whether the internal combustion engine is at idle; (c) checking whether a temperature upstream and downstream of the oxidation catalytic converter lies within a predetermined range; (d) if each of steps (a), (b), and (c) is answered in the affirmative, actively intervening in an engine management to establish a predetermined temperature in the oxidation catalytic converter; (e) actively generating HC by way of a late post-injection of fuel; (f) measuring a lambda value upstream and downstream of the oxidation catalytic converter when the predetermined temperature in step (d) is reached and while HC is actively being generated in step (e); (g) determining a difference between the lambda values upstream and downstream of the oxidation catalytic converter; and (h) characterizing the oxidation catalytic converter as damaged if the difference between the lambda values upstream and downstream of the oxidation catalytic converter in step (g) is smaller than a predetermined value.