Abstract: The present disclosure describes a method for checking the signal of a temperature sensor in an exhaust-gas aftertreatment system for an internal combustion engine. The method may include: in an operating state which does not require heating of the reducing agent, activating the heating device for the purposes of checking the temperature sensor; determining whether the signal of the temperature sensor changes by a predefined expected value (?T) within a predefined time period (?t2); provisionally identifying the temperature sensor as fault-free if it does; deactivating the heating device; determining whether the signal of the temperature sensor reaches the start temperature (T0) again within a time period (?t3); and confirming the temperature sensor as fault-free if it does.

Abstract: The present disclosure describes a method for checking the signal of a temperature sensor in an exhaust-gas aftertreatment system for an internal combustion engine. The method may include: in an operating state which does not require heating of the reducing agent, activating the heating device for the purposes of checking the temperature sensor; determining whether the signal of the temperature sensor changes by a predefined expected value (?T) within a predefined time period (?t2); provisionally identifying the temperature sensor as fault-free if it does; deactivating the heating device; determining whether the signal of the temperature sensor reaches the start temperature (T0) again within a time period (?t3); and confirming the temperature sensor as fault-free if it does.

Abstract: In a method and a device for adapting the injection agent supply for an emission control system, the following steps are carried out: a) setting of a agent pressure target value in the line upstream of the pump in relation to the ambient pressure; b) opening of the pressure relief valve for a predetermined time t; c) determining the pressure difference between the target and the injection agent pressure, caused in step b), immediately after step b); d) setting a target value for the agent pressure in the line downstream of the pump in relation to the exhaust gas pressure in the system; e) opening of the injector for a predetermined time t; f) determining the pressure difference between the target and the agent pressure, caused in step e), immediately after step e); g) comparing the pressure differences from steps c) and f); and h) optional adaptation of the injector opening time.

Abstract: In a method for adapting the reducing agent feed in an exhaust gas aftertreatment system having an SCR catalyst for removing nitrogen oxides from the exhaust gas of an internal combustion engine and at least one reducing agent feed device, the minimum opening time of the reducing agent feed device is determined during operation and while suspending nitrogen emission, carrying out the following steps: a) the opening time of the reducing agent feed device is gradually prolonged until b) a reducing agent-sensitive sensor in the exhaust gas aftertreatment system detects a reducing agent signal. An exhaust gas aftertreatment system is designed accordingly for carrying out the method and a device is designed for controlling an exhaust gas aftertreatment system.

Abstract: A method for controlling an SCR-exhaust gas after-treatment system (1) of an internal combustion engine (8), in particular of an internal combustion engine of a motor vehicle, has one or more steps for determining the quality of the reducing means.

Abstract: In a method and a device for adapting the injection agent supply for an emission control system, the following steps are carried out: a) setting of a agent pressure target value in the line upstream of the pump in relation to the ambient pressure; b) opening of the pressure relief valve for a predetermined time t; c) determining the pressure difference between the target and the injection agent pressure, caused in step b), immediately after step b); d) setting a target value for the agent pressure in the line downstream of the pump in relation to the exhaust gas pressure in the system; e) opening of the injector for a predetermined time t; f) determining the pressure difference between the target and the agent pressure, caused in step e), immediately after step e); g) comparing the pressure differences from steps c) and f); and h) optional adaptation of the injector opening time.

Abstract: In a method for adapting the reducing agent feed in an exhaust gas aftertreatment system having an SCR catalyst for removing nitrogen oxides from the exhaust gas of an internal combustion engine and at least one reducing agent feed device, the minimum opening time of the reducing agent feed device is determined during operation and while suspending nitrogen emission, carrying out the following steps: a) the opening time of the reducing agent feed device is gradually prolonged until b) a reducing agent-sensitive sensor in the exhaust gas aftertreatment system detects a reducing agent signal. An exhaust gas aftertreatment system is designed accordingly for carrying out the method and a device is designed for controlling an exhaust gas aftertreatment system.

Abstract: A method for controlling an SCR-exhaust gas after-treatment system (1) of an internal combustion engine (8), in particular of an internal combustion engine of a motor vehicle, has one or more steps for determining the quality of the reducing means.