Abstract: A method of operating an engine includes determining a relative position between a first camshaft and a second camshaft during a startup event of the engine when the first camshaft is at a first home position and the second camshaft is at a second home position. The first home position is a first preset angular position of the first camshaft relative to a crankshaft. The second home position is a second preset angular position of the second camshaft relative to the crankshaft when the engine is in an OFF state. The method includes generating a first estimate of the first home position. The method also includes diagnosing a mis-build of the engine based on the relative position, the first estimate and a second estimate of the second home position.

Abstract: A system for diagnosing a switchable roller finger follower (SRFF) and an oil control valve (OCV) includes a signal monitoring module and a fault detection module. The signal monitoring module receives at least one of an individual cylinder fuel correction (ICFC) signal and an air/fuel ratio imbalance (AFIM) signal when: an engine speed signal is within a predetermined range of speed; an engine load signal is within a predetermined range of load; and a charcoal canister vapor signal is within a predetermined range of flow rate. The fault detection module detects a fault of at least one of a SRFF and an OCV based on an exhaust gas recirculation value and at least one of the ICFC and AFIM signals. The ICFC and AFIM signals are generated based on: an engine position signal; and at least one of an oxygen signal and a wide range air fuel signal.

Abstract: A method and control module includes a manifold absolute pressure comparison module that determines a function of the manifold absolute pressure and an average manifold absolute pressure for a plurality of cylinders and that compares the manifold absolute pressure parameter to a manifold absolute pressure threshold. The control module includes a misfire event module that compares the misfire parameter to a misfire threshold. A hardware remedy module performs a valve actuation hardware remedy in response to comparing the manifold absolute pressure and comparing the misfire parameter.

Abstract: An engine control system for a homogenous charge compression ignition (HCCI) engine includes a fuel injector temperature determination module and a fuel injector control module. The fuel injector temperature determination module determines a temperature of a tip of a fuel injector based on a first temperature model when the HCCI engine is operating in an HCCI combustion mode, and determines the temperature of the tip of the fuel injector based on a second temperature model when the HCCI engine is operating in a spark ignition (SI) combustion mode. The fuel injector control module controls a fuel injector pulse width based on the determined temperature and a predetermined temperature threshold, wherein the fuel injector pulse width increases when the determined temperature is greater than the predetermined temperature threshold.

Abstract: A method and system for controlling an engine includes a desired fuel mass determination module that determines fuel mass for injection into a cylinder. The system also includes a split determination module that splits the fuel mass into split fuel masses and a pulsewidth determination module that converts the split fuel masses into injection pulsewidths outside of an injector operation exclusion zone.

Abstract: An engine control system for a homogenous charge compression ignition (HCCI) engine includes an airflow determination module and a sensor diagnostic module. The airflow determination module generates a first plurality of estimates of airflow into the HCCI engine when the HCCI engine is operating in a first combustion mode, wherein the first plurality of estimates are based on an intake manifold absolute pressure (MAP), a mass air flow (MAF) rate, and a camshaft position. The sensor diagnostic module determines a state of at least one of a first plurality of sensors based on a predetermined threshold and differences between one of the first plurality of estimates and others of the first plurality of estimates, wherein the first plurality of sensors includes a MAP sensor, a MAF sensor, and a camshaft sensor.

Abstract: A diagnostic system and method for operating the same includes a pressure monitoring module generating a diagnostic pressure signal and a camshaft driven engine component correction module generating an engine component oil pressure correction signal and generating a corrected diagnostic pressure signal based on the diagnostic pressure signal and the engine component oil pressure signal. The system further includes a diagnostic module generating a failed variable valve lift mechanism signal based on the corrected diagnostic pressure signal.

Abstract: A method and system for controlling an engine includes a normal individual cylinder fuel correction determination module determining normal pulse mode individual cylinder fuel corrections in a normal pulse mode. The system also includes a split pulse enable module operating the fuel injectors in split pulse mode having a linear pulse and a ballistic pulse smaller than the linear pulse. The system also includes a split pulse individual cylinder fuel correction determination module determining split pulse mode individual cylinder fuel corrections in the split pulse mode. The system also includes a ballistic pulse adaptation module adjusting ballistic pulse calibration values in response to the normal pulse mode individual cylinder fuel corrections and the split pulse mode individual cylinder fuel corrections to form adjusted ballistic pulse calibration values.

Abstract: A method of operating an engine includes determining a relative position between a first camshaft and a second camshaft during a startup event of the engine when the first camshaft is at a first home position and the second camshaft is at a second home position. The first home position is a first preset angular position of the first camshaft relative to a crankshaft. The second home position is a second preset angular position of the second camshaft relative to the crankshaft when the engine is in an OFF state. The method includes generating a first estimate of the first home position. The method also includes diagnosing a mis-build of the engine based on the relative position, the first estimate and a second estimate of the second home position.

Abstract: An air/fuel imbalance (AFIM) diagnostic system comprises a first module, an imbalance determination module, and an imbalance diagnostic module. The first module outputs imbalance data samples based on an oxygen signal provided by an oxygen sensor measuring oxygen in exhaust expelled from cylinders of a cylinder bank. The imbalance determination module determines an AFIM value based on the imbalance data samples. The imbalance diagnostic module selectively diagnoses an AFIM in the cylinder bank based on the AFIM value.

Abstract: A system and method for controlling fuel delivery through a fuel injection system to an internal combustion engine is described. An engine controller calculates a mass of fuel for delivery to one of the cylinders through one of the fuel injectors, based upon the operation of the internal combustion engine. Gas temperature in the intake runner of the cylinder is determined, and a compensation term is selected based upon the calculated mass of fuel and the determined gas temperature in the intake runner of the cylinder. The calculated mass of fuel is adjusted using the compensation term, and the controller controls open time of the fuel injector based upon the adjusted calculated mass of fuel.

Abstract: A stored relationship between air/fuel ratio and the output voltage of a wide-range exhaust gas oxygen sensor is automatically re-calibrated under any air/fuel ratio condition. Once an engine control module records oxygen sensor voltages under stoichiometric and deceleration fuel cut-off conditions, the air/fuel ratio that corresponding to any sensor voltage can be calculated. In operation, the sensor voltage recorded during fuel cut-off is used to determine first and second lump-sum parameters that relate sensor output voltage to air/fuel ratio under lean and rich operating conditions, respectively. The determined parameters are compared with previously determined values, and when the comparison indicates that at least a predetermined change the sensor operating characteristics has occurred, the parameters are used to re-calibrate the stored sensor voltage vs. air/fuel ratio relationship.

Abstract: A control method for a direct injection gasoline engine operable in stratified or homogenous combustion modes and having a fuel vapor purge system estimates the hydrocarbon concentration of purge vapor during open loop fuel control in the stratified combustion mode, and controls the fuel injection quantity and the combustion mode based on the estimated concentration. The hydrocarbon concentration of the purge vapor is estimated during open-loop fuel control by measuring the air/fuel ratio error during steady state operation with no fuel vapor purging, and using such air/fuel ratio error to normalize the air/fuel error observed during steady state operation with purge control. The fuel injection quantity is compensated for the estimated purge vapor concentration, and engine combustion mode is determined in part based on a comparison of the estimated concentration with a calibrated threshold.

Abstract: An improved method of operation for an electromechanical purge valve of a vehicle evaporative emission control system reduces the activation level of the purge valve below a nominal minimum level by a variable offset amount under specified operating conditions to lower purge flow. Specifically, the low flow control is permitted when the fuel in the purge vapor being drawn into the engine exceeds a calibrated percentage of the engine fuel requirement and the activation level of the purge valve has been reduced to the nominal minimum, provided that the system voltage level is at or above a specified value. When low flow control is permitted, the offset amount is incrementally increased so long as the engine fuel control is able to maintain the air/fuel ratio error at or below a calibrated amount, and incrementally decreased when the low flow control is no longer permitted or the air/fuel ratio becomes lean enough to potentially degrade combustion stability.

Abstract: An improved method of operation for an electro-mechanical purge valve of a vehicle evaporative emission control system reduces the activation level of the purge valve below a nominal minimum level by a variable offset amount under specified operating conditions to lower purge flow. Specifically, the low flow control is permitted when the fuel in the purge vapor being drawn into the engine exceeds a calibrated percentage of the engine fuel requirement and the activation level of the purge valve has been reduced to the nominal minimum, provided that the system voltage level is at or above a specified value. When low flow control is permitted, the offset amount is incrementally increased so long as the engine fuel control is able to maintain the air/fuel ratio error at or below a calibrated amount, and incrementally decreased when the low flow control is no longer permitted or the air/fuel ratio becomes lean enough to potentially degrade combustion stability.

Abstract: A control method for a direct injection gasoline engine operable in stratified or homogenous combustion modes and having a fuel vapor purge system estimates the hydrocarbon concentration of purge vapor during open loop fuel control in the stratified combustion mode, and controls the fuel injection quantity and the combustion mode based on the estimated concentration. The hydrocarbon concentration of the purge vapor is estimated during open-loop fuel control by measuring the air/fuel ratio error during steady state operation with no fuel vapor purging, and using the measured steady state air/fuel ratio error to normalize the air/fuel error observed during steady state operation with purge control. The fuel injection quantity is compensated for the estimated purge vapor concentration, and engine combustion mode is determined in part based on a comparison of the estimated concentration with a calibrated threshold.