Abstract: A method for operating an internal combustion engine includes providing a vehicle having an internal combustion gasoline engine including multiple cylinders and wherein the engine is capable of running on at least one of a plurality firing fractions, providing a vacuum offset (Offsetvac) to adjust airflow capacity for each of the plurality of firing fractions, determining a torque capacity of each of the plurality firing fractions and a plurality of available firing fractions that provides at least enough torque capacity to accommodate a current torque requested (Treq), determining a plurality of viable firing fractions of the plurality of available firing fractions, and determining and implementing an optimal firing fraction of the viable firing fractions if the optimal firing fraction provides enough fuel economy benefit over a current firing fraction.

Abstract: A method for operating an internal combustion engine includes providing a vehicle having an internal combustion gasoline engine including multiple cylinders and wherein the engine is capable of running on at least one of a plurality firing fractions, providing a vacuum offset (Offsetvac) to adjust airflow capacity for each of the plurality of firing fractions, determining a torque capacity of each of the plurality firing fractions and a plurality of available firing fractions that provides at least enough torque capacity to accommodate a current torque requested (Treq), determining a plurality of viable firing fractions of the plurality of available firing fractions, and determining and implementing an optimal firing fraction of the viable firing fractions if the optimal firing fraction provides enough fuel economy benefit over a current firing fraction.

Abstract: A system according to the principles of the present disclosure includes an air/fuel ratio determination module and an emission level determination module. The air/fuel ratio determination module determines an air/fuel ratio based on input from an air/fuel ratio sensor positioned downstream from a three-way catalyst that is positioned upstream from a selective catalytic reduction (SCR) catalyst. The emission level determination module selects one of a predetermined value and an input based on the air/fuel ratio. The input is received from a nitrogen oxide sensor positioned downstream from the three-way catalyst. The emission level determination module determines an ammonia level based on the one of the predetermined value and the input received from the nitrogen oxide sensor.

Abstract: A system according to the principles of the present disclosure includes a valve lift determination module and a fault detection module. The valve lift determination module determines valve lift based on at least one of a first period when a valve is open and N differences between a first value of a valve lift signal generated by a valve lift sensor when the valve is closed and a second value of the valve lift signal when the valve is open, wherein N is an integer greater than one. The fault detection module detects a fault in a valve actuator based on the valve lift.

Abstract: A vehicle system includes a position sensor, a current supply module, and a mode indicator module. The position sensor includes: an electromagnet (EM) that generates a magnetic field proximate to one of an intake valve and an exhaust valve of an engine; and a Hall-effect sensor that generates a position signal indicating a position of the one of the intake valve and the exhaust valve based on the magnetic field. The current supply module supplies current to the EM. The mode indicator module indicates whether the one of the intake valve and the exhaust valve is being actuated in a low lift mode or a high lift mode based on the position signal.

Abstract: A system according to the principles of the present disclosure includes a valve lift determination module and a fault detection module. The valve lift determination module determines valve lift based on at least one of a first period when a valve is open and N differences between a first value of a valve lift signal generated by a valve lift sensor when the valve is closed and a second value of the valve lift signal when the valve is open, wherein N is an integer greater than one. The fault detection module detects a fault in a valve actuator based on the valve lift.

Abstract: A method of regulating a torque output of a vehicle powertrain includes generating a plurality of torque requests and associating each of the plurality of torque requests with one of a plurality of arbitration domains to form torque request sets associated with each of the plurality of arbitration domains. A first torque request set is arbitrated within a first of the plurality of arbitration domains to provide a first torque request. The first torque request is introduced into a second torque request set associated with a second of the plurality of arbitration domains. The second torque request set is arbitrated within the second arbitration domain to provide a second torque request. A torque source is regulated based on the second torque request.

Abstract: An engine mode control system for an internal combustion engine includes a transition control module and an intake cam phaser control module. The transition control module controls a transition from a first engine mode to a second engine mode and determines a desired air mass. The engine is operated at a first air/fuel ratio (AFR) in the first engine mode and at a second AFR in the second engine mode. The desired air mass is based on the second AFR. The intake cam phaser control module adjusts the intake cam phaser based on the desired air mass during the transition.

Abstract: A vehicle system includes a position sensor, a current supply module, and a mode indicator module. The position sensor includes: an electromagnet (EM) that generates a magnetic field proximate to one of an intake valve and an exhaust valve of an engine; and a Hall-effect sensor that generates a position signal indicating a position of the one of the intake valve and the exhaust valve based on the magnetic field. The current supply module supplies current to the EM. The mode indicator module indicates whether the one of the intake valve and the exhaust valve is being actuated in a low lift mode or a high lift mode based on the position signal.

Abstract: A method of valve lift failure detection may include determining first and second intake air pressures in an engine having intake valve lifters that selectively operate intake valves in first and second lift modes. The first intake air pressure may correspond to an intake stroke of a first piston of the engine when the engine is commanded to operate in the first lift mode and the second intake air pressure may correspond to an intake stroke of a second piston of the engine when the engine is commanded to operate in the first lift mode. The method may further include determining a difference between the first and second intake air pressures and diagnosing an intake valve lifter failure when the difference exceeds a predetermined limit.

Abstract: An engine control system comprises a fuel pump control module and a diagnostic module. The fuel pump control module controls a pressure pump to inject fuel into a fuel rail. The diagnostic module determines an estimated pressure increase within the fuel rail based on the injected fuel, compares an actual pressure increase within the fuel rail to the estimated pressure increase, and indicates when the actual pressure increase is less than the estimated pressure increase.

Abstract: A diagnostic system for an engine includes a phaser control module that commands a first cam phaser position of a cam phaser of the engine for a first period and a second cam phaser position of the cam phaser for a second period, and a phaser diagnostic module that diagnoses a phaser control error for the cam phaser based on a first pressure of fluid supplied by an oil control valve to the cam phaser measured during the first period, and a second pressure of fluid supplied by the oil control valve to the cam phaser measured during the second period. The first and second pressures are measured on one of an advance-side fluid chamber and a retard-side fluid chamber of the cam phaser. The phaser diagnostic module detects one of a phaser mechanical fault and a phaser hydraulic system fault. A related method is also provided.

Abstract: A system according to the principles of the present disclosure includes an air/fuel ratio determination module and an emission level determination module. The air/fuel ratio determination module determines an air/fuel ratio based on input from an air/fuel ratio sensor positioned downstream from a three-way catalyst that is positioned upstream from a selective catalytic reduction (SCR) catalyst. The emission level determination module selects one of a predetermined value and an input based on the air/fuel ratio. The input is received from a nitrogen oxide sensor positioned downstream from the three-way catalyst. The emission level determination module determines an ammonia level based on the one of the predetermined value and the input received from the nitrogen oxide sensor.

Abstract: A method and control module includes a control hold duty cycle module generating a control hold duty cycle signal and a voltage correction module generating a voltage correction signal. The control module also includes a correction module generating a corrected proportional correction signal based on a proportional correction signal and the voltage correction signal, and generating a corrected integral correction signal based on an integral correction signal and the voltage correction signal. The control module also includes a force determination module controlling a duty cycle to a phaser operator based upon the control hold signal, the corrected proportional correction signal and the corrected integral correction signal.

Abstract: A control system and method for controlling a fuel system of an engine includes a steady state determination module determining the engine is operating at a steady state and a memory storing a first fuel correction. A fuel pump control module commands a predetermined fuel rail pressure change. The memory stores a second fuel correction after the predetermined fuel rail pressure change. A sensor error correction module determines a fuel rail pressure sensor error based on the first fuel correction and the second fuel correction and determines a fuel rail pressure in response to the sensor error.

Abstract: A system includes a pressure signal adjustment module that generates a maximum pressure signal based on a fluid pressure signal from a pressure sensor of a camshaft phaser system of an engine. The pressure signal adjustment module detects a maximum peak value of the fluid pressure signal and maintains the maximum pressure signal at the maximum peak value for a peak and hold period. A diagnostic module detects a fault of the camshaft phaser system based on the maximum pressure signal during the peak and hold period.

Abstract: A control system for a powertrain of a vehicle includes a torque module and a damping control module. The torque module determines a first output torque and a second output torque of the engine. The second output torque is determined after the first output torque. The torque module also determines a torque difference based on the first output torque and the second output torque. The damping control module generates a damping torque in a transmission based on the torque difference.

Abstract: A valve lifter control system includes a valve lifter control module and a forced transition determination module. The valve lifter control module determines a desired lift state of a valve lifter based on at least one of engine speed and engine load. The forced transition determination module initiates a forced transition of the valve lifter from the low-lift state to the high-lift state based on manifold vacuum independently of the desired lift state.

Abstract: A camshaft phasor control system for an engine includes a first camshaft position sensor that generates a first camshaft position signal based on a position of a first camshaft. A first summer generates a first error signal based on the first camshaft position signal and a first commanded position signal. A control module generates a raw duty cycle based on the first error signal. A second summer generates a modified duty cycle based on the raw duty cycle and a modifier. The control module generates the modifier based on the first error signal and speed of the first camshaft relative to a second camshaft.

Abstract: A system for controlling a variable valve lift system of an engine comprises a delay module that estimates a total delay based on at least one of a measured and an estimated delay of the variable valve lift system. A variable valve control module commands one of a first transition from a variable valve low-lift profile to a variable valve high-lift profile and a second transition from a variable valve high-lift profile to a variable valve low-lift profile based on the total delay.