Gm Global Technolgoy Operations, Inc.

David N Belton

Wenbo Wang

Richard B Jess

Igor Anilovich

Janean Kowalkowski

Louis A Avallone

Vincent A White

Ian J Mac Ewen

Chang H Kim

John F Van Gilder

Steven Jeffrey Schmieg

Vincent J Tylutki

Wajdi B Hamama

Jon C Miller

Robert J Genslak

Jeffrey M Hutmacher

Gregory J York

Ian J Macewen

Christopher R Graham

Daniel G Bolstrum

David A Frank

Jaehak Jung

J Michael Ellenberger

William Western

Lyle E Hamilton

Matthew J Roelle

Randy L Dufresne

Jianyang Geng

Richard W Amann

Colleen Marie Maier

Chris R Thelen

Fang-Cheng J Fu

A system operates to bypass one or more exhaust purifying devices during deceleration fuel cut-off (DFCO) events in order to avoid hydrocarbon purging. The system includes an internal combustion engine and exhaust purifying system including a first purifying device and a second purifying device. An exhaust gas sensor monitors an exhaust gas feedstream. A diverter valve is disposed to manage the exhaust gas feedstream and fluidly coupled to an exhaust diversion pipe. A controller detects operation of the engine in a DFCO state and monitors the exhaust gas feedstream via the exhaust sensor. The diverter valve is controlled to divert the exhaust gas feedstream away from at least one of the first and second purifying devices during the DFCO event when the exhaust gas feedstream has an air/fuel ratio that is greater than a threshold air/fuel ratio.

Method and apparatus for managing flow through an exhaust aftertreatment system

A monitoring system for a single can oxidation catalyst (OC)/particulate filter (PF) member includes a controller including a first temperature sensor input configured to receive a first exhaust temperature upstream of an OC portion of the single can OC/PF member, a second temperature sensor input configured to receive a second exhaust temperature downstream of the first temperature. The controller is configured and disposed to calculate an exothermic capacity of the OC portion and determine washcoat deterioration of a PF portion of the single can OC/PF member based on the exothermic capacity of the OC portion.

Monitoring system for a single can oxidation catalyst/particulate filter

The capacity of a platinum-containing diesel oxidation catalyst (DOC) to simultaneously convert NO to NO, CO to carbon dioxide, and remaining hydrocarbons to carbon dioxide and water in the exhaust system of a vehicle diesel engine may be evaluated and diagnosed using measured DOC exhaust inlet temperatures and outlet temperatures at a relatively high exhaust temperature and, soon thereafter, at a relatively low exhaust inlet temperature. Values of the platinum-containing DOC exotherms at the high and low DOC inlet temperatures are found to provide a basis for evaluation of both NO conversion and the HC and CO conversion capabilities of the DOC. The process may be repeated as the catalyzed DOC conversion efficiency changes with use. The practice may also be used to evaluate the performance of oxidation catalysts used in a like way in treating the exhaust from a lean-burn gasoline engine.

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An exhaust control system for a vehicle comprises an exhaust system modeling module and an actuator control module. The exhaust system modeling module estimates an input gas temperature, an output gas temperature, a mass temperature, and a pressure for an exhaust system component of an exhaust system implemented in the vehicle. Exhaust gas flows through the exhaust system component. The actuator control module selectively adjusts an engine operating parameter based on at least one of the input gas temperature, the output gas temperature, the mass temperature, and the pressure.

Exhaust temperature and pressure modeling systems and methods

A method comprises modifying combustion parameters of an engine of a hybrid vehicle to provide an engine power level insufficient to maintain crankshaft rotation at a desired speed including increasing a temperature of an exhaust gas and reducing an emissions content of the exhaust gas; and supplementing the engine power level with an electric machine of the hybrid vehicle to maintain crankshaft rotation at the desired speed. A control module comprises a cold start combustion control module that modifies combustion parameters of an engine of a hybrid vehicle to provide an engine power level insufficient to maintain crankshaft rotation at a desired speed, wherein the modifying includes increasing a temperature of an exhaust gas, and reducing an emissions content of the exhaust gas; and an electric machine control module that supplements the engine power level using an electric machine of the hybrid vehicle to maintain crankshaft rotation at the desired speed.

Control system for cold start emissions reduction in hybrid vehicles

An oxygen storage capacity (OSC) monitoring system for a vehicle having a catalytic converter includes a control module that determines a measured OSC based on an inlet sensor signal (ISS) that is responsive to an oxygen content of exhaust flowing into the catalytic converter. The control module determines a normalization ratio based the measured OSC and determines a PASS/FAIL status of the catalytic converter based on the normalization ratio.

Normalizing oxygen storage capacity(OSC) for catalyst monitoring

An oxygen storage capacity (OSC) monitoring system for a vehicle having a catalytic converter includes an inlet oxygen sensor that generates an inlet sensor signal (ISS) based on an oxygen content of exhaust flowing into the catalytic converter. A control module receives the ISS, increases a closed loop fuel control gain during a first period and determines a fuel control factor based on the ISS during the first period. The control module determines an OSC when an average value of the fuel control factor is greater than a first value and is less than a second value during the first period.

Fuel control for robust detection of catalytic converter oxygen storage capacity

A method comprises operating an engine of a vehicle to provide output torque to an input of a torque converter, determining whether the engine is in a cold start condition, fixing an input shaft of a transmission when the engine is in the cold start condition, and coupling the input shaft of the transmission to an output of the torque converter. A control module comprises a combustion control module that operates an engine of a vehicle to provide output torque to an input of a torque converter, a NPD module that determines whether the engine is in a cold start condition, and a transmission control module that fixes an input shaft of a transmission when the engine is in the cold start condition, wherein the input shaft of the transmission is in communication with an output of the torque converter.

Enhanced catalyst performance by engine load adjustment

A method for detecting emissions from an internal combustion engine generally including determining a reference air/fuel mixture signal based on an engine speed and an airflow into the engine. The method includes determining an actual air/fuel mixture signal from an air/fuel mixture sensor and comparing the reference air/fuel mixture signal to the actual air/fuel mixture signal. The method also includes determining whether an air/fuel imbalance condition occurs based on the comparison and setting a service indicator based on the determination of whether the air/fuel imbalance condition occurred.

Air/fuel imbalance detection system and method

A method of generating a metric data set for determining a performance of a catalytic converter includes sampling data from a post catalytic converter oxygen sensor to provide a raw data set and generating a revised data set based on the raw data set. Data within the revised data set is eliminated based on characteristics of data points of the revised data set and the revised data set is filtered to provide the metric data set.

Method for diagnosing catalytic converter performance

An engine diagnostic system includes a catalytic converter and an outlet Osensor. The outlet Osensor generates an outlet signal that is based on an oxygen level of exhaust gases exiting the catalytic converter. A controller adjusts a secondary fuel trim based on the outlet signal. The controller indicates a fault status if the secondary fuel trim has achieved a fuel trim limit and the outlet signal is out of a diagnostic range.

A method and control system for verifying cold start emissions reduction control in a vehicle using an internal combustion engine utilizes measured engine speed and commanded ignition timing to calculate an estimated actual engine-out thermal energy flow. An expected thermal energy flow is calculated based on designed engine speed and ignition timing. A residual energy flow is calculated based on a difference between the estimated actual thermal energy flow and the expected thermal energy flow. Meanwhile, a system quality-weighting factor is calculated based on several measured engine parameters. A qualified energy flow residual is calculated based on the system quality weight and the residual energy flow. The qualified energy residual flow is accumulated, averaged based on the accumulated quality weight, and then filtered. Diagnostic control determines that if the cold start emissions reduction control is operating correctly based on the filtered averaged qualified energy flow residual comparing a predetermined range.

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Birmingham, MI, United States of America

David N Belton