Method and device for the functional verification of a by-pass element

The invention relates to a method for functional testing of a bypass element (24) that regulates the exhaust gas flow of an internal combustion engine (1) via the exhaust turbine (44) of an exhaust gas turbocharger (40) and a bypass (22) bypassing it, wherein the method comprises at least the following steps: a) opening of the bypass element (24); b) measurement of the exhaust gas temperature in the bypass (22); and c) processing of the measurement data for the detection of malfunctions. The invention further relates to a device for functional testing of a bypass element (24) that regulates the exhaust gas flow of an internal combustion engine (1) via the exhaust turbine (44) of an exhaust gas turbocharger (40) and a bypass (22) bypassing it, wherein the device comprises at least one temperature sensor (221) that is installed in the bypass (22).