Gm Global Technolgoy Operations, Inc.

Delphi Technologies, Inc.

Steve L Melby

Kevin J McKay

Rebecca J Darr

Kenneth M Simpson

Chad E Marlett

Andrew D Herman

Hallett D Breidenbach

David Allen Dues

Stephen Paul Levijoki

Paul Jasinkiewicz

Yun Xiao

James M Perrin

Michael J Steckler

Rebecca A Oemke

A method for monitoring an internal combustion engine includes monitoring thermal efficiency in a heat exchanger of an exhaust gas recirculation (EGR) system with a flow control valve commanded to a first, open state and monitoring thermal efficiency in the heat exchanger with the flow control valve commanded to a second, closed state. The flow control valve is evaluated based upon the monitored efficiencies.

Method and apparatus for monitoring a coolant system for an exhaust gas recirculation system

A method for assessing a cold start emission reduction (CSER) strategy applied to an engine system is provided. The method determines a first accumulation value based on an estimated output signal that would result from applying a first control command to the engine system. The method determines a second accumulation value based on a measured output signal resulting from applying a second control command that implements the CSER strategy to the engine system. The method compares the first accumulation value and the second accumulation value. The method determines whether the applying the second command to the engine system achieved a performance threshold of the CSER strategy based on the comparing.

Monitoring cold start emission reduction strategy

A cold start emissions reduction diagnostic system for an internal combustion engine includes a coolant temperature module including a coolant temperature input, and a memory module having a coolant temperature look-up table. The cold start controller also includes a cold start emissions reduction module configured to selectively compare coolant temperature values with desired emission values in the look-up table to determine at least one of a fuel injection timing and a fuel injection quantity to establish a desired cold start emissions profile. A fuel injection monitoring module is configured and disposed to sense changes in fuel injection timing and fuel injection quantity, and an emission reduction diagnostic model module is configured and disposed to determine emission parameters based on the changes in the one of the fuel injection timing and fuel injection quantity sensed by the fuel injection monitoring module during a cold start.

Cold start emissions reduction diagnostic system for an internal combustion engine

A system and method of operating an exhaust gas recirculation (EGR) system of a vehicle includes controlling an EGR valve actuable between an EGR enabled position and an EGR disabled position, such that with the EGR valve in the EGR enabled position a portion of exhaust gas emitted from an engine is directed through an EGR cooler for recirculation into the engine, and with the EGR valve in the EGR disabled position the exhaust gas is not recirculated through the engine. An EGR coolant temperature is predicted based on measured engine speed, vehicle speed, outside ambient temperature, and commanded fuel level of the vehicle. The EGR valve is actuated to the EGR disabled position when the predicted EGR coolant temperature is equal or greater than an EGR coolant temperature threshold. The EGR coolant temperature is predicted without direct measurement of engine coolant temperature.

Exhaust gas recirculation cooler protection system and method

A method of regenerating a particulate filter of an exhaust system is provided. The method includes determining a first regeneration mode based on a soot level; generating control signals to a first fuel injector associated with an engine based on the first regeneration mode; determining a second regeneration mode based on the soot level; and generating control signal to a second fuel injector associated with an exhaust stream of the exhaust system based on the second regeneration mode.

Regeneration methods and systems for particulate filters

A vehicle includes an engine, an exhaust system, a selective catalytic reduction (SCR) device, a first and a second NOx sensor configured to respectively measure an upstream and a downstream NOx level, and a controller or host machine. The controller, via the present method, calculates a NOx conversion efficiency rate of the SCR device using the NOx levels from the sensors. At the end of a key cycle when an accumulated amount of upstream NOx is less than a calibrated upstream NOx level, the controller determines if the NOx conversion efficiency rate is presently passing or failing. The accumulated upstream NOx is recorded in memory for use in calculating the NOx conversion efficiency rate during a subsequent key cycle only when the NOx conversion efficiency rate is presently passing at the end of the key cycle. A control system for the vehicle uses the controller and sensors as noted above.

Method and system for controlling a nitrogen oxide (NOx) conversion efficiency monitor

A system includes an engine configured to operate in a first operating state and a second operating state, a particulate filter configured to receive exhaust gas from the engine and filter particulate matter from the exhaust gas, and an oxidation catalyst configured to generate heat to increase a temperature of the exhaust gas during a regeneration process. A sensor is configured to measure an actual temperature of the exhaust gas during the regeneration process. A controller is configured to define a fuel conversion factor based, at least in part, on the actual temperature and an expected temperature of the exhaust gas. The controller is further configured to analyze the fuel conversion factor over time relative to at least one of the first and second operating states of the engine and diagnose a fault in the regeneration process based, at least in part, on the fuel conversion factor.

Hydrocarbon conversion diagnostic

A control module comprises a thermal detection module and a protection module. The thermal detection module receives temperature data of a particulate matter filter and determines a temperature based on the temperature data. The protection module selectively reduces output of an engine when the temperature is greater than a temperature threshold. A method comprises receiving temperature data of a particulate matter filter and selectively reducing output of an engine when a temperature based on the temperature data is greater than a temperature threshold.

Thermal detection and protection of vehicle hardware

The rationality of a measured temperature of transmission fluid is assessed by comparing it to an engine coolant temperature. The rationality assessment is enabled when the ambient air temperature is reliably determined and deemed normal, a sufficient soak condition is confirmed, and the measured temperature, the engine temperature and the ambient air temperature are all within prescribed ranges. The rationality assessment monitors the ambient temperature relative to the initial engine temperature during the assessment period, and the assessment is disabled if the ambient air temperature deviates from the initial engine temperature by more than a calibrated value.

Method and apparatus for assessing the rationality of a transmission fluid temperature measure

A default value of transmission input speed in a motor vehicle powertrain having an automatic-shift multi-gear ratio power transmission is continuously updated based on a measured value of the input speed and other reliable speed data including transmission output speed and engine speed. The default value is substituted for the measured input speed when a malfunction of the input speed sensor is detected, and transitions back to the measured input speed when the input speed sensor malfunction is no longer present.

Method of determining a default transmission input speed

A default value of transmission output speed in a motor vehicle powertrain having an automatic-shift multi-gear ratio power transmission is continuously updated based on a measured value of the output speed and other reliable speed data including transmission input speed and vehicle speed. The default value is substituted for the measured output speed when a malfunction of the output speed sensor is detected, and transitions back to the measured output speed when the output speed sensor malfunction is no longer present.

Method of determining a default transmission output speed

An improved method of testing for evaporative emission system leaks monitors vacuum decay in a closed system so that the effects of fuel tank expansion during the test interval are minimized. In a first embodiment pass/fail criteria are established in terms of the time required for the system pressure to decay by a calibrated amount for a predetermined leak size. A leak at least as large as the predetermined leak is detected if the measured time is shorter than a calibrated time. The effects of fuel tank expansion are minimized because the changes in fuel tank volume occur primarily due to the pressure differential across the tank, as opposed to the leak size, and the changes that occur during the test are essentially the same for any leak size under consideration. In a second embodiment, the pass/fail criteria are established in terms of the change in pressure that occurs in the calibrated time; a leak at least a large as the predetermined leak is detected if the measured change in pressure is larger than the calibrated pressure amount.

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Howell, MI, United States of America

Steve L Melby