A method for the diagnosis of an air supply circuit supplying air to a burner of an exhaust gas after-treatment system for an exhaust system of an internal combustion engine, wherein the air supply circuit is provided with a pumping device housed along a first duct adjusted by a shut-off valve. The method entails housing a first pressure sensor along the first duct interposed between the pumping device and the burner; housing a second pressure sensor along a second duct out of the burner; acquiring the pressure signals detected by said first and second pressure sensors; and diagnosing faults and/or malfunctions in the air supply circuit depending on the pressure signals detected by said first and second pressure sensors.

The invention relates to a method for exhaust gas aftertreatment in an internal combustion engine. For purposes of the exhaust gas aftertreatment in the internal combustion engine, an exhaust gas system is provided in which a first three-way catalytic converter is arranged, as seen in the direction in which the exhaust gas of the internal combustion engine flows through the exhaust gas system, while at least another three-way catalytic converter is arranged downstream from the first three-way catalytic converter. Here, at least one lambda probe is arranged in an exhaust gas channel of the exhaust gas system upstream from the appertaining three-way catalytic converters. In the proposed method, a component temperature of the three-way catalytic converters is determined and compared to a light-OFF temperature. In this process, the lambda control of the internal combustion engine is carried out by means of the lambda probe upstream from the last three-way catalytic converter that has reached its light-OFF temperature.

Moreover, according to the invention, an exhaust gas aftertreatment system for carrying out such a method is being proposed.

An engine system may include an intake line, and a cylinder deactivation (CDA) device selectively deactivating a portion of combustion chambers in the engine. The engine system may further include a first exhaust manifold connected to a first plurality of combustion chambers mounted with the CDA device, a second exhaust manifold connected to a second plurality of combustion chambers without the CDA device, a first exhaust line connected to the first exhaust manifold, a second exhaust line connected to the second exhaust manifold, and a third exhaust line connected with the first and second exhaust lines through an exhaust gas processing device. In addition, a turbocharger including a turbine is mounted at the first exhaust line and rotated by exhaust gas. An air injection device may supply air to the second exhaust manifold or the second exhaust line in a catalyst heating mode of the exhaust gas processing device.

The present disclosure relates to internal combustion engines. The teachings thereof may include monitoring a secondary air system with which secondary air is introduced into exhaust of the internal combustion engine wherein individual cylinders of the internal combustion engine are associated with one of at least two cylinder banks and a separate exhaust duct is associated with each cylinder bank. The methods may include delivering secondary air with a compression arrangement via a common secondary air line divided into a number of individual secondary air sublines corresponding to the number of exhaust ducts at a branching point downstream of the compression arrangement; controlling the secondary air to simultaneously enable or inhibit the flow to the individual secondary air sublines; detecting values for the pressure downstream of the compression arrangement and upstream of the branching point; detecting pulsations of a pressure in each cylinder bank when the compression arrangement is activated and the throughflow control arrangement set into the open state; summing the pulsations; comparing each of summed-up values with threshold values; and if the respective threshold value is exceeded, identifying a fault in the throughflow control arrangement.

An aftertreatment system includes an exhaust reductant tank configured to store an exhaust reductant. A filter is fluidically coupled to the exhaust reductant tank. The aftertreatment system includes a hydrocarbon detection device configured to indicate the presence of a hydrocarbon in the exhaust reductant. A catalyst is included in the system and configured to treat the exhaust reductant flowing through the system. The hydrocarbon detection device can include a hydrophobic paper, and can be disposed in the filter.

Methods and systems using model based and iterative calculations of mass flow throughout an internal combustion engine system. A secondary air injection valve is provided to selectively allow intake air to pass to the exhaust side of the engine system to aid in exothermic reaction with exhaust gasses exiting the engine for various purposes. The iterative calculations of mass flow include estimation of the mass flow through the secondary air injection valve.

A method for operating an exhaust burner, which is situated in an exhaust system downstream from an internal combustion engine of a motor vehicle. Prior to and during a start phase of the exhaust burner, an air-mass flow supplied to a combustion chamber of the exhaust burner is increased, in particular in a strictly monotonical manner, between a start time in a starting air-mass flow and a further time in a further air-mass flow. Prior to the further time, fuel is supplied to the combustion chamber. A fuel-air mixture is produced in the combustion chamber from the fuel and air of the air-mass flow. The fuel-air mixture is ignited with the aid of an ignition device which is continuously hot or forms ignition sparks intermittently.

An aftertreatment system includes an exhaust reductant tank configured to store an exhaust reductant. A filter is fluidically coupled to the exhaust reductant tank. The aftertreatment system includes a hydrocarbon detection device configured to indicate the presence of a hydrocarbon in the exhaust reductant. A catalyst is included in the system and configured to treat the exhaust reductant flowing through the system. The hydrocarbon detection device can include a hydrophobic paper, and can be disposed in the filter.

Described herein is a method for detecting steady state ammonia slip for a motor vehicle having an internal combustion engine and an emissions control system. The emissions control system includes a selective catalytic reduction (SCR) device, a NOx sensor, and a controller. The controller executes a method for ammonia slip detection that includes determining if the SCR device is at steady state, comparing a NOx measurement from the NOx sensor with a predicted NOx value. If the NOx measurement exceeds the predicted NOx value by a threshold, perturbing a reductant injection, the perturbation having a selected magnitude and a selected duration. The method also includes measuring a NOx value resulting from the perturbation and computing a gradient thereof relative to the measured NOx, and ascertaining if a gradient of the NOx resulting from the perturbation exceeds a threshold and identifying a reductant slip condition if so.

The invention relates to a method for exhaust treatment of an internal combustion engine, in particular for regeneration of a particle filter in the exhaust gas duct of an internal combustion engine, wherein the particle filter becomes loaded with soot particles during normal operation of the internal combustion engine. To reach the regeneration temperature of the particle filter, the internal combustion engine is operated with a rich fuel mixture, while secondary air is being introduced into the exhaust gas duct at the same time, and the unburned fuel components are reacted exothermically with the secondary air on the particle filter until the particle filter has heated up to the regeneration temperature. Once the regeneration temperature has been reached, the internal combustion engine is operated at a stoichiometric combustion air ratio, and secondary air is injected into the exhaust gas duct for oxidation of the soot particles retained in the particle filter, wherein control of the amount of secondary air is accomplished by means of a lambda probe downstream from an introduction point for the secondary air and upstream from the particle filter.