Gm Global Technolgoy Operations, Inc.

David A Frank

Frank Ament

David Brian Brown

Igor Anilovich

Wenbo Wang

Shengbing Jiang

Chaitanya Sankavaram

David N Belton

Ian J Mac Ewen

Bryant G Hammond

Brian L Buck

Martin L Hall

Janelle Kane Rolando

A method of root cause diagnosis of fault data from a vehicle includes identifying a first vehicle fault and selecting from field repair data a vehicle feature corresponding to the identified first vehicle fault. The method also includes identifying from the field repair data an effective repair of the identified first vehicle fault. The method additionally includes training and testing via a machine learning algorithm, a labor code classifier using the identified effective repair of the first vehicle fault and the selected vehicle feature corresponding to the identified first vehicle fault. The method also includes identifying and classifying, using the trained classifier, indistinguishable labor codes. Furthermore, the method includes communicating the identified and classified indistinguishable labor codes for diagnosing a root cause of real time first vehicle fault data. A computer-readable medium storing an executable computer algorithm for performing the root cause diagnosis of vehicle fault data is also envisioned.

Vehicle fault root cause diagnosis

A valve assembly defines a chamber and three ports. A first valve selectively obstructs a first port to prevent fluid communication between a secondary air injection pump and the chamber. A second valve selectively obstructs a second port to prevent fluid communication between an air intake manifold and the chamber. A third port provides fluid communication between the chamber and an exhaust manifold. The chamber thus serves as a common passageway for secondary air flowing from the pump to the exhaust manifold and for exhaust gas flowing from the exhaust manifold to the air intake manifold. In a preferred embodiment, the first and second valves are rigidly interconnected.

Engine valve assembly

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.

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A vehicle exhaust system includes a catalytic converter and an outlet sensor. The outlet sensor generates a sensor signal based on an oxygen level of exhaust gases exiting the catalytic converter. A controller communicates with an engine and the outlet sensor, and monitors the sensor signal during a predetermined period of engine operation. The controller commands an intrusive catalyst monitor test in a default order if the outlet sensor signal transitions through both thresholds during a predetermined period. The controller performs an intrusive outlet sensor test during cruise operation of the engine if the signal fails to transition through both thresholds during the catalyst monitor test.

Method and apparatus for monitoring catalyst efficiency and outlet oxygen sensor performance

An improved method of &ldquo;adaptive&rdquo; control that optimizes NO conversion efficiency while minimizing fuel consumption. This method limits the NO level in the feedstream to a NO catalyst to a level that the catalyst can process by adjusting certain engine parameters, namely exhaust gas recirculation percentage, air-to-fuel ratio, and spark ignition timing in a spark-ignition engine or fuel injection timing in a compression-ignition engine. This method results in improved fuel efficiency over previous methods of controlling NO emissions by allowing longer periods of lean operations.

NOX catalyst exhaust feedstream control system

A method for controlling regeneration fuel supplied to an internal combustion engine operating with a lean fuel-air mixture during sequential rich mixture regeneration events of a NOx adsorber in which NOx emissions collected by the adsorber are purged to provide optimum emissions control and minimum fuel consumption. The method monitors the exhaust gases flowing out of the adsorber during the regeneration event to detect when fuel-air mixture to the engine is within an excessively lean or rich range. When the sensed exhaust gases contain an excessively lean fuel-air mixture, fuel is increased to the engine. Fuel is decreased when the sensed exhaust gases contain an excessively rich fuel-air mixture. The fuel can be increased or decreased by adjusting the duration or fuel rate of the regeneration event.

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Rochester Hills, MI, United States of America

David A Frank