Chrysler Corporation

Daimlerchrysler Corporation

Karin Rak

Mary Joyce

Shean P Huff

Gary L Seitz

Yi Cheng

Robert J Nankee, Ii

Richard K Moote

Mark E Hope

Jerry Kennie

Howard W Krausman

William D Rotramel

Roland T Richardson

Dennis A Krozek

Madhu B Banerjee

Francis M Fodale

John Smiley, Iii

John M Prevost

William O Robinson

Alan Richard Ward

Stuart M Davis

Patrick T McCourt

Michael D Hesse

Michael Ray Lindsay

Jesse Mitchell Saier

John R Dombrowski

Lawrence Cramer

David R DeRain

Bruce Dorow

Maura P O'Kennedy

An apparatus for determining the validity of a data signal communicated between two microprocessors by a dual port RAM includes a sender for providing a data signal and an initialization status indicator and a dual port RAM in communication with the sender for receiving the data signal and the initialization status indicator. The RAM has a first location for storing the data signal and a second location for storing the initialization status indicator. The sender performs initialization on the RAM at the beginning of a data transfer cycle which includes a plurality of data transfer from the sender to a receiver. The sender updates the initialization status indicator as the initialization progresses. The receiver reads the initialization status of the RAM from the second location and subsequently reads the data signal from the first location in association with the initialization status of the RAM.

Dual port RAM communication protocol

A computer-implemented software development system is provided for constructing applications that are embedded in a microcontroller of a motor vehicle. The development system includes a data dictionary which stores data type information for a plurality of vehicle parameters and is able to generate a parameter definition file having data type information for each vehicle parameter associated with a first application. A calibration repository is used to generate a calibratable file for the first application, where the calibratable file includes calibratable vehicle information and controller executable instructions for the first application. The parameter definition file and the calibratable file are then used by a calibration tool to calibrate the first application in relation to a particular motor vehicle.

Software development framework for constructing embedded vehicle controller software

The present invention provides a flexible fuel compensation system for determining the percent alcohol content of fuel in a flexible fueled vehicle at the instance of fueling and in an open loop operating mode. According to the invention, two estimated percent alcohol content values are calculated based on the old fuel mixture's alcohol content and two fueling possibilities. A first value is calculated for the possibility that E85 fuel was added to the tank and a second value is calculated for the possibility that E0 fuel was added to the tank. If the inferred ethanol content increases above a positive threshold during closed loop operation, the system assumes that E85 fuel has been added to the tank. Conversely, if the inferred ethanol content decreases below a negative threshold, the system assumes that E0 fuel was added to the tank. Accordingly, if the vehicle is shut down before a more accurate ethanol content determination is complete, the inferred ethanol content follows either the first or second estimated alcohol content value until the system reaches a closed loop operating condition.

Method of determining the composition of fuel in a flexible fueled vehicle after fuel blending

A method is provided for triggering a system for learning the percent alcohol content of a fuel used in a motor vehicle capable of operating on more than one type of fuel. The fuel composition learning system is triggered each time fuel is added to the vehicle's fuel tank, each time the engine is started when the fuel volume in the fuel tank falls below a given value or if a fuel level sending unit malfunction has been detected. The fuel composition learning system is also triggered if an error is detected in the value of the learned percent alcohol content of the fuel.

Method of triggering a determination of the composition of fuel in a

The present invention provides a method of controlling operating parameters of a motor vehicle capable of operating on more than one type of fuel. The methodology employs a separate idle air control enrichment fuel multiplier for optimizing idle air control operating conditions. The methodology also employs a separate transient enrichment fuel multiplier for optimizing transient operating conditions.

Fuel control enhancements for a sensorless flexible fueled vehicle

The present invention is directed towards a method of controlling combustion parameters of an internal combustion engine prior to oxygen sensor feedback availability for a flexible fueled vehicle. If the vehicle has previously been running on ethanol or has been using ethanol in the recent past, a first strategy is employed which basis engine fueling on the minimum of a theoretically appropriate fueling value and a theoretically calculated value. If the vehicle has not previously been running on ethanol or has not been using ethanol in the recent past, a second strategy is employed which basis engine fueling on the minimum of the theoretically appropriate fueling value, the theoretically calculated value and a roughness calculated value.

Method of determining the composition of fuel in a flexible fueled

The present invention provides a method of compensating for an erroring sensor in a flexible fuel compensation control system for a flexible fueled vehicle. The methodology provides a method for identifying preselected operating conditions without the output of the erroring sensor. As such, the flexible fuel compensation control system may still be employed to ensure vehicle drivability even in the absence of input from an erroring sensor.

Method of compensating for a failed sensor in a flexible fueled vehicle

The present invention provides a method for controlling combustion parameters of an internal combustion engine during wide open throttle or part throttle enrichment operation. Oxygen sensor rich and lean counts above and below a stoichiometric air/fuel ratio are counted during an injector pulse width period while a fuel concentration determination is being made at wide open throttle and part throttle enrichment. The ratio of lean counts to rich counts is compared to a calibratable value for incrementing the fuel concentration delivered to the internal combustion engine. The fuel concentration is further controlled if a boil-off condition is detected.

Method of controlling the air to fuel ratio in a flexible fueled vehicle

The present invention provides a method of controlling combustion parameters of an internal combustion engine without a PCV solenoid during a boil-off condition. The methodology detects a boil-off condition and implements one of two modes of boil-off compensation depending on the active status of an inferred alcohol content multiplier update system. The methodology also determines the nature of the air-flow through the internal combustion engine and determines the level of boil-off corruption present and the time when the corruption is complete. After the boil-off condition is determined to be complete, control of the combustion parameters are returned to a normal regime of a flexible fuel compensation system using the inferred alcohol content from the employed mode of boil-off compensation.

Method of compensating for boil-off alcohol in a flexible fueled vehicle

The present invention provides a flexible fuel compensation system for controlling operating parameters of an internal combustion engine based on a learned value of the percent alcohol content of the fuel using an oxygen feedback system. The methodology determines a fuel composition multiplier based on the percent alcohol content and implements gasoline operating parameters for the internal combustion engine if the fuel composition multiplier is less than a first threshold value, mixed gasoline/alcohol operating parameters if the fuel composition multiplier is greater than the first threshold value, and high concentration alcohol operating parameters if the fuel composition multiplier is greater than a second threshold value for a number of comparison checks. After a predetermined period, the fuel composition multiplier is updated and re-compared to the first and second thresholds and the appropriate one of the aforementioned operating parameters is implemented. A third update of the fuel composition multiplier is made if the determined fuel composition multiplier is less than the actual percent alcohol content of the fuel by more than a given amount.

The present invention provides a method for determining ethanol thresholds for a flexible fuel control system for a motor vehicle capable of operating on more than one type of fuel. Preferably, the ethanol threshold is determined from an off-idle purge-free cell from a matrix of fuel adaptive memory cells normally used to compensate for car-to-car variations in required fueling. The ethanol threshold is periodically reduced to compensate for levels of alcohol creep indicated by the amount of purge-free adaptive memory elevation. If the learned value of percent alcohol content of the fuel is less than the ethanol threshold, gasoline operating parameters are implemented for the internal combustion engine. The off-idle purge-free cell also provides a basis for interpolating an on-board diagnostic (OBDII) ethanol threshold. As such, the OBDII monitors are only enabled if the learned value of percent alcohol content of the fuel is less than the OBDII ethanol threshold.

Method of determining ethanol thresholds in a flexible fueled vehicle

The present invention provides a method for controlling the combustion parameters of an internal combustion engine with an oxygen sensor prior to a closed loop operating condition. If the output voltage of the oxygen sensor indicates a lean air to fuel ratio condition, the percent alcohol content is incremented to a limit based on an E85 possibility curve. If the voltage output of the oxygen sensor indicates a rich air to fuel ratio condition, the percent alcohol content is decremented to a limit based on an E0 possibility curve. After the end of the fuel blending period or when the internal combustion engine reaches a closed loop mode, control of the combustion parameters of the internal combustion engine are returned to normal regime oxygen sensor feedback control.

A method is provided for checking the function of a fuel composition sensor and for learning the percent alcohol content of a fuel used in a motor vehicle capable of operating on more than one type of fuel, as an alternative to a fuel composition sensor. The present invention improves the reliability of a motor vehicle utilizing a fuel composition sensor by allowing vehicle operation to continue uninterrupted, such as when a short or open condition exists within the sensor. The method first determines whether conditions are such that the percent alcohol content of a fuel should be 'learned'. If conditions are appropriated, then necessary engine operating conditions are first initialized. The oxygen sensor output signal is checked to determine whether the engine is operating too rich or lean. The value of percent alcohol content stored in the engine control unit's memory is modified in the direction of stoichiometric engine operation. In this manner, the engine is able to 'learn' the percent alcohol content of the fuel and make the appropriate adjustments to operating parameters.

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Farmington Hills, MI, United States of America

Mary Joyce