Method for injecting reactant into exhaust passage of internal combustion engine and apparatus for carrying out the method

摘要

A method for introducing a reagent medium into an exhaust gas conduit of an internal combustion engine, and an apparatus for carrying out the method. Provision is made for a diagnosis of the pressure sensor. In at least one first time interval in which a steady pressure state is expected, a check is made as to whether the pressure signal at least approximately corresponds to the steady-state pressure. In at least one second time interval in which a pressure change occurs, a check is made as to whether the pressure signal at least approximately corresponds to a predetermined test pressure and/or at least approximately exhibits a predetermined change with respect to the steady-state pressure. A fault signal is supplied if at least one of the conditions is not met.