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: 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: 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 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 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.

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 camshaft phasor control system for an engine includes a camshaft position sensor that generates a current camshaft position signal based on position of a camshaft. A first comparator generates a camshaft position signal based on the current camshaft position signal and a crankshaft position. The second comparator generates an error signal based on the relative camshaft position signal and a commanded camshaft position signal. A control module determines a current control hold duty cycle (CHDC) for a camshaft phasor based on an engine state parameter. The control module also generates a correction signal based on the error signal, adjusts the current CHDC based on the correction signal to generate a commanded CHDC signal, and generates another CHDC based on the commanded CHDC signal.

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 fuel injector diagnostic system includes a fuel pump control module, a pressure sensor, and a diagnostic module. The fuel pump control module disables delivery of fuel to a fuel rail of an engine. The pressure sensor measures a first pressure of the fuel rail before an injection event and a second pressure of the fuel rail after the injection event on at least one of a plurality of injectors when the engine is running. The diagnostic module diagnoses a fault in the at least one of the injectors based on the first pressure and the second pressure.

Abstract: A control system includes a fuel pump control module and a diagnostic module. The fuel pump control module controls a fuel pump to provide fuel to a fuel rail. The diagnostic module controls the fuel pump control module to provide a predetermined amount of fuel to the fuel rail, determines an estimated pressure increase within the fuel rail based on the predetermined amount of fuel, and compares an actual pressure increase within the fuel rail to the estimated pressure increase. The fuel pump control module selectively controls the fuel pump based on the comparison.

Abstract: An adaptive fuel delivery control system includes a pressure monitoring module and a flow rate determination module. The pressure monitoring module determines an actual pressure drop after a fuel injection event on an injector. The flow rate determination module determines an adjusted flow rate based on a reference flow rate and the pressure drop.

Abstract: A lift mechanism diagnostic system comprises a fuel pump disabling module, a pressure module, and a diagnostic module. The fuel pump disabling module selectively disables a fuel pump that is driven by a camshaft. The pressure module determines a first pressure of fluid provided to a variable valve lift mechanism when the variable valve lift mechanism is operated in a first lift mode while the fuel pump is disabled and determines a second pressure of the fluid when the variable valve lift mechanism is operated in a second lift mode while the fuel pump is disabled. The diagnostic module selectively diagnoses a fault in the variable valve lift mechanism based on the first and second pressures.

Abstract: A diagnostic system includes a first pressure monitoring module, a second pressure monitoring module, and a fault determination module. The first pressure monitoring module determines low-lift pressures and high-lift pressures in a cam phaser when a first oil control valve (OCV) moves first valve lifters to the low-lift state and the high-lift state, respectively. The second pressure monitoring module determines low-lift pressures and high-lift pressures in the cam phaser when a second OCV moves second valve lifters to the low-lift state and the high-lift state, respectively. The fault determination module diagnoses a fault in one of the first OCV and the second OCV based the low-lift pressures and the high-lift pressures.

Abstract: A solenoid diagnostic system includes a pressure monitoring module that determines a first pressure in an intake cam phaser for an intake camshaft and a second pressure in an exhaust cam phaser for an exhaust camshaft associated with a cylinder. A fuel injection monitoring module determines a fuel injection status associated with the cylinder. A fault determination module diagnoses a fault in a solenoid associated with the cylinder based on the first pressure, the second pressure, and the fuel injection status.

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 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 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.