Systems and methods for diagnosing at least one component in an exhaust aftertreatment system are provided. The system includes an exhaust aftertreatment system coupled to an engine system, at least one sensor, and at least one processing circuit structured to: receive initial sensor data; determine an initial parameter value based on the initial sensor data; determine that the initial parameter does not satisfy an initial threshold; perform operations to diagnose at least one component of the exhaust aftertreatment system comprising: causing the engine system to operate through a sequence of a plurality of engine outputs; receiving a plurality of sensor data, each of the plurality sensor data corresponding to at least one of the plurality of engine outputs; comparing each of the plurality of sensor data to a corresponding threshold; and diagnosing the at least one component based on the comparison.

A control system for use in a fluid flow application includes a heater and a control device. The heater includes at least one resistive heating element having a relationship between resistance and temperature defining a non-monotonic curve. The heater is to heat fluid flow. The control device is to determine a flow characteristic of the fluid flow and a temperature of the at least one resistive heating element along the non-monotonic curve between resistance and temperature based on a change in resistance of the at least one resistive heating element.

A diagnostic device for a sensor for measuring the position of a motor-vehicle drive shaft. The sensor includes a first wired communication link and a second wired communication link, via which wired communication links the sensor sends the signal, and being characterized by an average reference voltage. The diagnostic device for a sensor being intended to be electrically connected between the first wired communication link and the second wired communication link and being configured to: a) receive a first voltage value corresponding to the average voltage in the first wired communication link and a second voltage value corresponding to the average voltage in the second wired communication link; b) detect a short circuit on the first wired communication link; or c) detect a short circuit on the second wired communication link.

A method for controlling an internal combustion engine including at least one exhaust-gas aftertreatment component having an electric heating element, the electric heating element heating the exhaust-gas aftertreatment component and the exhaust gas flowing through the exhaust-gas aftertreatment component, the electric heating element briefly or permanently being acted upon by a heating current, a gas, in particular fresh air and/or exhaust gas, flowing downstream through the exhaust-gas path. In the method, a first temperature upstream from the at least one exhaust-gas aftertreatment component is ascertained, a second temperature downstream from the exhaust-gas aftertreatment component is ascertained, and the exhaust-gas mass flow of the internal combustion engine is ascertained as a function of a first temperature difference between the first and the second temperature and a heating power of the electric heating element, and the internal combustion engine is controlled as a function of the exhaust-gas mass flow.

The concepts described herein relate to a system, method, and/or apparatus for monitoring a NOx sensor that is arranged in an exhaust gas feedstream of an internal combustion engine downstream of an exhaust aftertreatment system to detect a fault related to the NOx sensor. This includes utilizing a catalyst efficiency model to detect occurrence of a fault that may indicate an in-range biased or stuck NOx sensor.

A sensor element of an A/F sensor AS has a solid electrolyte layer, a first electrode arranged on one side of the solid electrolyte layer so as to be exposed to the exhaust gas of an internal combustion engine, and a second electrode arranged on the other side of the solid electrolyte layer so as to face an atmospheric air chamber. The sensor element generates a sensor output according to the oxygen concentration in the exhaust gas. A microcomputer supplies oxygen to the first electrode side from the second electrode side via the solid electrolyte layer by applying a predetermined voltage between the pair of electrodes of the sensor element. Moreover, the microcomputer determines a crack abnormality of the solid electrolyte layer based on electric current between the pair of electrodes which is generated with start of the oxygen supply.

The present description relates generally to methods and systems for detecting thermal aging and blackening in oxygen sensors. Thermal aging and blackening effects may be differentiated based on a monitored change in impedance in each of a pump cell and a Nernst cell of the oxygen sensor following application of an alternating voltage. In response to detection of thermal aging and/or blackening in the oxygen sensor corrective measures may be taken to ensure accurate oxygen estimation using the sensor.

A PM detection system has a PM sensor, current detector, and control circuit. The circuit switches of a detection mode and a burning mode. In the detection mode, the control circuit prohibits supply of power to a heater and supplies a voltage between electrodes, and instructs the current detector to detect a current flowing between the electrodes. In the burning mode, the control circuit instructs the heater to generate heat energy to burn PM accumulated on an accumulation part. The control circuit judges PM has remained on the accumulation part when the detected current exceeds a threshold value, and performs the burning mode again. The system further has a pair of current detectors. Each current detector detects a leak current flowing from the heater to the electrodes through an insulation member when the heater generates heat energy. The circuit detects a sensor failure based on the detected leak current.

An abnormality diagnosis device includes a partially-plugged filter, a pressure difference sensor, a PM sensor, a first estimation portion estimating a diagnosis amount of PM from the partially-plugged filter, according to a running condition of the internal combustion engine, a second estimation portion estimating the diagnosis amount of PM according to an output of the pressure difference sensor, a third estimation portion estimating the diagnosis amount of PM according to an output of the PM sensor, and an abnormality diagnosis portion distinctly determining an abnormality of the internal combustion engine, an abnormality of the partially-plugged filter, and an abnormality of the PM sensor by comparing the diagnosis amount of PM estimated by the first estimation portion, the diagnosis amount of PM estimated by the second estimation portion, and the diagnosis amount of PM estimated by the third estimation portion.

A control device of an internal combustion engine according to the present invention executes air-fuel ratio control based on an output of an air-fuel ratio sensor provided at an upstream side of a catalyst, with correction based on an output of an oxygen sensor at a downstream side of the catalyst. When it is determined that a degree of an output tendency in a predetermined lean region is not less than a predetermined lean degree, and that a degree of an output tendency in a predetermined rich region is less than a predetermined rich degree based on lean tendency and rich tendency values representing output tendencies of the oxygen sensor, a limit is set to the correction in a direction to more suppress enriching of an air-fuel ratio as a degree is larger in which the output of the oxygen sensor is shifted to a lean side.