Volkswagen Ag

Volker Gehrke

Burkhard Veldten

Frank Alich

A method of testing the functionality of an oxidation catalytic converter of an internal combustion engine, particularly a diesel engine, of a motor vehicle, includes the following steps: (a) verifying whether the motor vehicle is at a standstill; (b) verifying whether the internal combustion engine is idling; (c) verifying whether a temperature lies within a predetermined range upstream and downstream of the oxidation catalyst. Then, if all of the steps (a) to (c) yield an affirmative result, an intervention in the engine management is made in such a way that a predetermined temperature is set in the oxidation catalyst; (e) hydrocarbons (HCs) are actively produced by post-injecting fuel at a late point in time; (f) a lambda value is measured upstream and downstream of the oxidation catalyst as soon as the predetermined temperature from step (d) has been reached, and while HCs are actively produced in step (e). Then, a difference is determined between the lambda values measured upstream and downstream of the oxidation catalyst. If the difference is less than a predetermined value, a conclusion is reached that the oxidation catalyst is damaged.

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Braunschweig, Germany

Volker Gehrke