The invention relates to a diagnostic method for checking the functionality of a component for the exhaust-gas aftertreatment of an internal combustion engine. For this purpose, in an internal combustion engine, a secondary air supply is provided by means of which an excess of oxygen can be generated in the exhaust gas channel essentially independently of the operating conditions of the internal combustion engine, and wherein said excess of oxygen is utilized for the measurement of an oxygen storage capacity of the component or of a signal change at the component. It is provided that the component is subsequently subjected to a substoichiometric exhaust gas in order that the oxygen release capacity or the signal change upon a change from superstoichiometric exhaust gas to a substoichiometric exhaust gas is also taken into consideration in the diagnosis. The invention also relates to a device for exhaust-gas aftertreatment, which is designed to be able to carry out a method of said type.

A sensor status indicator (SSI) assembly comprises a sensing interface configured to be communicatively coupled to a wiring harness of a sensor and receive a sensor signal therefrom. The sensor signal indicates a sensor status corresponding to a status of an apparatus to which the sensor is coupled. The SSI assembly also includes at least one visual indicator; and a controller communicatively coupled to the sensing interface and the at least one visual indicator. The controller is configured to interpret the sensor signal to determine the sensor status, and activate the at least one visual indicator to generate a visual signal corresponding to the sensor status.

Methods and systems are provided for emissions control of a vehicle. In one example, an emissions treatment device includes a porous substrate and a catalytic washcoat disposed thereon, the catalytic washcoat having nickel and no other metal. The porous substrate may be configured to filter particulate matter (PM) exiting the vehicle and the catalytic washcoat may be configured to oxidize at least a portion of the PM. The nickel in the catalytic washcoat may provide additional oxygen storage capacity and increased tolerance to sulfur poisoning of catalytic activity of the catalytic washcoat, further promoting PM oxidation. Moreover, because the catalytic washcoat may increase PM oxidation during passive regeneration events, a total number of active regeneration events may be decreased and fuel economy may be maintained.

A catalyst deterioration detection system 1 comprises an air-fuel ratio sensor 41, a current detection device 61, a voltage application device 60, a voltage control part 71, an air-fuel ratio control part 72 and a deterioration judging part 73. The air-fuel ratio control part executes fuel cut control, and, after the fuel cut control, executes rich control. The voltage control part, if judging that the air-fuel ratio of the outflowing exhaust gas has reached the stoichiometric air-fuel ratio when setting the applied voltage to a first voltage in a limit current region during the rich control, changes the applied voltage from the first voltage to a second voltage in a limit current region. The deterioration judging part judges the degree of deterioration of the catalyst based on the output current of the air-fuel ratio sensor when the applied voltage is set to the second voltage.

The abnormality diagnosis system 1, 1, 1 of an ammonia detection device 46, 71 comprises: an air-fuel ratio detection device 41, 72 arranged in the exhaust passage 22 at the downstream side of the catalyst 20; an air-fuel ratio control part 51 configured to control an air-fuel ratio of exhaust gas; and an abnormality judgment part 52 configured to judge abnormality of the ammonia detection device. The air-fuel ratio control part performs rich control making the air-fuel ratio of the inflowing exhaust gas richer than a stoichiometric air-fuel ratio. The abnormality judgment part judges that the ammonia detection device is abnormal if, after start of the rich control, an output value of the ammonia detection device does not rise to a reference value before the air-fuel ratio detected by the air-fuel ratio detection device falls to a rich judged air-fuel ratio richer than a stoichiometric air-fuel ratio.

A power system for a work vehicle includes an engine that generates exhaust gas, an exhaust treatment system that treats the exhaust gas, and an electronic control system coupled to the engine and the exhaust treatment system and implementing a maintenance management system. The maintenance management system is configured to receive a first identifier associated with a first sensor or actuator device installed in the exhaust treatment system, store the first identifier in memory, receive a second identifier associated with a second sensor or actuator device installed in the power system of the work vehicle, compare the first identifier to the second identifier to determine that the first identifier differs from the second identifier and that the second sensor or actuator device is a replacement for the first sensor or actuator device in the exhaust treatment system, and clear any fault codes associated with the first sensor or actuator device.

In order to detect the degree of deterioration of one catalyst with a simple configuration, a catalyst deterioration judging device for an internal combustion engine includes an upstream catalyst disposed in an engine exhaust passage, a downstream catalyst disposed in the engine exhaust passage downstream of the upstream catalyst, an inflow air-fuel ratio sensor for detecting the air-fuel ratio of an inflow exhaust gas to the upstream catalyst, an outflow air-fuel ratio sensor for detecting the air-fuel ratio of an outflow exhaust gas from the downstream catalyst, and an electronic control unit. The maximum oxygen storage amount of the upstream catalyst is detected based on the output of the inflow air-fuel ratio sensor and the output of the outflow air-fuel ratio sensor when the upstream catalyst is in the active state and the downstream catalyst is in the inactive state.

A vehicle particulate matter contamination recovery system includes a particulate matter filter receiving exhaust gas from an engine. A particulate matter sensor is positioned downstream of the particulate matter filter, the particulate matter sensor collecting a non-combustible contaminant on a circuit of the particulate matter sensor and generating a current indicating presence of the non-combustible contaminant. A total volume of water collected during multiple cold start operations of the engine is passed onto the sensor acting to at least partially dissolve the non-combustible contaminant. The particulate matter sensor is operated in a remedial action mode of operation having no voltage applied to the circuit of the particulate matter sensor until a quantity of the cold start operations corresponding to the total volume of water is reached.

Methods and systems are provided for detecting NOx sensor degradation based on results from a NOx sensor self-diagnostic (SD) test performed after a key-off event. In one example, a method may comprise waiting a duration to perform a SD test of a NOx sensor after a key-off event until engine operating conditions stabilize and reach a set of qualifying conditions. One or more SD tests may be performed after waiting the duration, but outputs generated under conditions where one or more of a temperature at the sensor is greater than a threshold, and an oxygen concentration is outside a threshold range, may be excluded when determining whether or not the NOx sensor is degraded.

Disclosed is an exhaust gas aftertreatment system (1) for a diesel engine, the exhaust gas aftertreatment system comprising: a treatment agent tank (2) for storing an exhaust gas treatment agent; a metering injection module (4), with the injection of the metering injection module (4) being controlled with a determined duty ratio signal according to a desired injection amount; a supply module (3) connected between the treatment agent tank (2) and the metering injection module (4) for supplying the exhaust gas treatment agent to the metering injection module (4); an exhaust gas treatment agent pipe (6) connected between the metering injection module (4) and the supply module (3); a pressure sensor for measuring the system pressure in the exhaust gas treatment agent pipe (6); and a controller (7); wherein the controller (7) is configured to receive a system pressure signal from the pressure sensor during injection of the metering injection module (4), and detect an injection abnormality of the metering injection module (4) based on at least a first amount, which represents an actual injection amount and is determined by the system pressure signal, and a second amount, which represents a theoretical injection amount and is determined by a corresponding duty ratio signal. A corresponding injection abnormality detection method is further disclosed. The injection abnormality detection method is simple and reliable.