Patent ID: 7665295
Filing Date: 2010-02-23
Classification: F01N,Y02T

Abstract:
1. A method for operating an internal combustion engine in whose exhaust-gas region an exhaust-gas treatment device is situated, comprising: introducing a reagent into the exhaust-gas region upstream in front of the exhaust-treatment device; immediately and directly spraying the reagent into the exhaust-gas region, wherein in a flow direction of the reagent, which is brought to a predefined reagent source pressure, a switchable reagent safety valve is arranged first and then a continuous reagent dosing valve, the reagent dosing valve being disposed in the exhaust-gas region; recording a reagent pressure in a reagent path, the reagent path being between the reagent safety valve and the reagent dosing valve; comparing the reagent pressure detected in at least one predefined state of at least one of the reagent safety valve, and the reagent dosing valve, to at least one threshold value, wherein the comparing step includes: providing a fault signal in case of a threshold exceedance.