Siemens Aktiengesellschaft

Michael K&auml;sbauer

Christian Birkner

Arno Friedrich

For the checking of an exhaust gas recycling valve, the control signal for the exhaust gas return valve is returned from a defined value to zero, in the idle state of the internal combustion engine while the vehicle is at a standstill and the reaction of the signal (MAF) from an airflow detector in the inlet tract is evaluated. Should the signal not exceed a given threshold value (MAE SWD), within a first time period (T2), then a faulty dynamic is assigned to the exhaust recycling valve. Should the signal not exceed a second given threshold value (MAF SWS), within a second time period (T3), then it is determined that the exhaust recycling valve can not be completely shut.

Method for functional checking of an exhaust recycling system on an internal combustion engine

The invention relates to the diagnosis of an exhaust gas recycling valve, whereby, on switching off the internal combustion engine, the throttle valve and the exhaust recycling valve are closed and a check is made of whether a compression is detectable in the cylinders of the internal combustion engine, by means of an engine speed check within a segment. Should an engine speed difference (Ndiff) be greater than a threshold value (Ndiff SW), then an incompletely closed exhaust gas recycling valve is recognized, assuming a complete closure of the throttle valve.

Growing community of inventors

Neutraubling, Germany

Michael Käsbauer

Growing community of inventors

Neutraubling, Germany

Michael K&auml;sbauer

Michael Käsbauer