Method and device for operating an internal combustion engine with a throttle valve and with an exhaust gas recirculation system for detecting a soaked EGR line

摘要

Method and device for carrying out the method, which provides the following steps: opening an exhaust gas recirculation valve (108) of an internal combustion engine (100), closing a throttle valve (104) of the internal combustion engine (100), detecting a value for an intake manifold pressure of the internal combustion engine (100) when the exhaust gas recirculation valve ( 108) and closed throttle valve (104), comparing the value with a first threshold value and a second threshold value (B) which is greater than the first threshold value, recognizing an operating state of the internal combustion engine (100), depending on whether the value lies in a value range between the first threshold and the second threshold (B) or outside this range. This makes it possible to monitor various air system components, in particular sooting the EGR return path, and enables “pin pointing”, which can also be used to locate a defective component.