Gm Global Technolgoy Operations, Inc.

Benjamin Radke

Janean Kowalkowski

Vincent J Tylutki

Marek L Wilmanowicz

Jason J Chung

Scott McLane

John David Barta

An exhaust treatment system includes a particulate filter having a filter substrate configured to trap soot contained in exhaust gas. A regeneration system is configured to perform a regeneration operation that regenerates the particulate filter by burning away soot stored in the filter substrate. A control module is in electrical communication with the regeneration system to generate a first control signal that initiates the regeneration operation based on a comparison between at least one operating condition of the exhaust treatment system and a threshold value. The control module generates a second control signal in response to detecting at least one diagnostic signal. The second control signal initiates the regeneration operation independently of the comparison.

Regeneration system to regenerate a particulate filter based on code clear diagnostic signal

A method of detecting a thermal event is provided that relies not only on monitored exhaust temperatures, but also on temperature gradients propagating in the direction of exhaust flow. Specifically, the method of detecting a thermal event in a vehicle exhaust system includes monitoring at least one operating parameter at multiple locations spaced in exhaust flow of the vehicle exhaust system. The method then includes initiating a protective action if the monitoring indicates that at least one respective predetermined temperature requirement and a respective predetermined temperature gradient requirement are exceeded at two of the multiple temperature sensor locations within a predetermined time period.

Method of detecting a thermal event in an exhaust system based on temperature gradients and exhaust system configured for same

A system and method for initiating an engine after-run state and controlling a nitrogen oxide sensor self-diagnostic tool are provided. The system may include an internal combustion engine, an exhaust system, a selective catalytic reduction (SCR) device and at least two NOx sensors to measure the efficiency of the SCR device and a controller or host machine. The controller, via the present method, executes a first control action to disable the self-diagnostic tool when one of an occurrence of a particulate filter regeneration event and a non-occurrence of a calibration threshold is detected. The controller executes a second control action, initiating an engine after-run state and enabling the self-diagnostic tool when one of a non-occurrence of a particulate filter regeneration event and an occurrence of the calibration threshold is detected.

Method and system for initiating an engine after-run state and controlling a nitrogen oxide sensor self-diagnostic tool

An exhaust gas treatment system includes a particulate filter to collect particulate matter from exhaust gas flowing therethrough. A regeneration module performs a regeneration operation that regenerates the particular filter. The regeneration operation generates an exothermic event which heats the particulate filter above a target temperature that burns the particulate matter. At least one temperature sensor is disposed adjacent the particular filter to determine at least one temperature of the exhaust gas. The exhaust gas treatment system further includes a temperature diagnostic module to determine a temperature profile of the particulate filter based on the temperature of the exhaust gas. The temperature diagnostic module further determines a temperature deviation of the particulate filter based on a comparison between the temperature profile and a target temperature. The temperature diagnostic module diagnoses the regeneration operation based on a plurality of temperature deviations and a selected time period.

Event-based deviation integration temperature control loop diagnostic system

In one embodiment of the invention, a method for determining an exhaust system condition includes determining if a reaction in an oxidation catalyst is performing acceptably based on a determined temperature of the exhaust gas flowing from the oxidation catalyst and determining a temperature of the exhaust gas flowing from a particulate filter. The method further includes determining a temperature of the exhaust gas flowing into the oxidation catalyst, determining an exhaust system condition based on a first difference between the temperature of the exhaust gas flowing from the particulate filter and the temperature of the exhaust gas flowing from the oxidation catalyst and a second absolute difference between the temperature of the exhaust gas flowing from the oxidation catalyst and the temperature of the exhaust gas flowing into the oxidation catalyst and communicating a signal to identify the determined exhaust system condition.

System and method for determining an exhaust system condition

A vehicle includes an engine, an exhaust system having a particulate filter which removes soot from the exhaust stream, a sensor, and a controller. The sensor measures instantaneous differential pressure across the filter. The controller executes a method to selectively enable or disable execution of an efficiency diagnostic of the filter as a function of a learned differential pressure offset value. The controller may also compare the differential pressure to a calibrated threshold and execute a control action when the differential pressure falls within an allowable range of the threshold. This may include applying the differential pressure offset value and enabling execution of the diagnostic using measurements from the zeroed sensor. Another control action may be executed when the measured differential pressure is not within the allowable range of the threshold, including disabling the execution of the diagnostic and setting a diagnostic code indicating that the sensor may be faulty.

Differential pressure-based enablement of a particulate filter diagnostic

A method of monitoring a differential pressure sensor of an exhaust gas aftertreatment system includes sensing a learned value (n&#x2212;1, n, n+1, n+2, etc.) of the differential pressure sensor for each after-run occurrence of the vehicle, and calculating an absolute value of a rate of change between a current (n) learned value of the differential pressure sensor and a previous (n&#x2212;1) learned value of the differential pressure sensor. The absolute value of the rate of change is compared to a threshold pressure value to determine if the absolute value of the rate of change is greater than the threshold pressure value or is less than the threshold pressure value. A fault in the differential pressure sensor is signaled when the absolute value of the rate of change of the learned values is greater than the threshold pressure value.

Method of monitoring a differential pressure sensor of an exhaust gas treatment system

A system for a vehicle includes a regeneration module and a disconnection indication module. The regeneration module indicates when a regeneration of a particulate filter is complete. The disconnection indication module receives a pressure difference across the particulate filter measured using delta pressure sensor. The delta pressure sensor generates the pressure difference based on first and second pressures upstream and downstream of the particulate filter applied to the delta pressure sensor using upstream and downstream pressure lines, respectively. In response to an indication that the regeneration of the particulate filter is complete, the disconnection indication module selectively indicates that the downstream pressure line is disconnected based on a comparison of the pressure difference and a predetermined pressure.

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Waterford, MI, United States of America

Benjamin Radke