Patent ID: 8180555

Claim:
A method of evaluating a pressure at a dosing valve of a fuel metering device for metering fuel into an exhaust gas system of a combustion engine, wherein a component of the combustion engine is assigned to the exhaust gas system for at least one of a regeneration, a temperature impingement and a thermo management, and wherein fuel is metered in a flow direction of the exhaust gas in front of the component with an injection valve from a cycle duration and a duty cycle relation of a switching signal for controlling a shut-off valve and the dosing valve depending on a difference pressure, the method comprising: determining a wrap curve from a measured pressure of a pressure sensor arranged in a flow direction of the fuel behind the dosing valve; and generating an offset characteristic line for determining a modeled pressure difference value, wherein a pressure difference value for a pressure measured in front of the dosing valve is replaceable with the modeled pressure difference value.