Methods and systems are provided for mitigating spark plug wet-fouling in an engine system. In one example, a method may include, after spark plug wet-fouling has been detected prior to an engine start, selecting between drying one or more of the wet-fouled spark plugs by routing a heated gas through one or more engine cylinders and by routing a compressed gas through the one or more engine cylinders. In this way, on-demand airflow may be provided to expedite spark plug drying.

Systems and methods for correcting an engine intake camshaft position and an engine exhaust camshaft position for a variable valve timing engine are described. In one example, intake manifold pressure of an engine is sampled while a motor/generator rotates the engine at a predetermined speed without fuel being supplied to the engine. A camshaft angle where minimum intake manifold pressure is observed is a basis for correcting camshaft position.

A drive control section automatically stops an engine by stopping fuel injection and by closing a throttle valve that adjusts the amount of intake air when a predetermined specified condition is satisfied. A stopping-angle detection section detects a crank angle when the engine is automatically stopped as a stopping angle. The drive control section cranks the engine before an in-cylinder negative pressure period, in which pressure in a cylinder of the engine is negative pressure, elapses after starting to automatically stop the engine if the stopping angle is outside an allowable crank-angle range in which it is possible to restart the engine by cranking the engine by the motor generator.

The method for controlling valve timing for a turbo engine includes: classifying control regions depending on an engine speed and an engine load; applying a maximum duration to an intake valve and applying a long duration to an exhaust valve in a first control region; applying the maximum duration to the intake and applying the long duration to the exhaust valve in a second control region; applying the long duration to the exhaust valve and advancing an intake valve closing (IVC) timing in the third control region; applying a short duration to the exhaust valve and controlling the IVC timing in the fourth control region; controlling a wide open throttle valve (WOT) and applying the short duration to the exhaust valve in the fifth control region; controlling a WOT and controlling the IVC timing by applying the long duration to the exhaust valve in the sixth control region.

Methods and systems are provided for adjusting vehicle noises to notify the vehicle operator of speed changes in human-in-the-loop cruise control and semi-autonomous vehicle operation. In one example, a method for drive unit of a vehicle may include responsive to a vehicle speed meeting a predefined condition relative to a threshold vehicle speed, adjusting one or more drive unit actuators to modulate engine noise while maintaining desired wheel torque within a threshold.

By calculating a throttle opening learning value based on an actual effective opening area calculated based on the actual flow rate of intake air and an actual throttle opening with respect to variations caused by type differences of throttle valves and by calculating a throttle opening learning completion range indicating the region for which throttle opening learning completion has been determined based on the state of deviation between an effective opening area corrected by throttle opening learning and the actual effective opening area, control that applies the throttle opening learning value or fail-safe of an air flow sensor is performed in a contiguous throttle opening learning completion range.

A method of controlling intake and exhaust cam phase in an internal combustion engine includes sensing an engine speed and an engine load of the internal combustion engine, sensing or estimating a wall temperature of a cylinder of the internal combustion engine, utilizing the engine speed and the engine load in one or more lookup tables based on the cylinder wall temperature to determine intake phaser constraint values and exhaust phaser constraint values for cold operation of the internal combustion engine, and transitioning the intake phaser constraint values and the exhaust phaser constraint values for cold operation to intake phaser constraint values and exhaust phaser constraint values based on one or more lookup tables for normal hot operation of the internal combustion engine.

Methods and systems are provided for improving fuel usage while addressing knock by adjusting the use of spark retard and direct injection of a knock control fluid based on engine operating conditions and the composition of the injected fluid. One or more engine parameters, such as EGR, VCT, boost, throttle position, and CMCV, are coordinated with the direct injection to reduce torque and EGR transients.

A method for controlling intake and exhaust valves of an engine includes: controlling, by an intake continuous variable valve timing (CVVT) device and an exhaust CVVT device, opening and closing timings of the intake valve and exhaust valves; determining, by a controller, a target opening duration of the intake and exhaust valves based on an engine load and an engine speed; modifying, by an intake continuous variable valve duration (CVVD) device and by an exhaust CVVD device, current opening and closing timings of the intake valve and/or exhaust valve based on the target opening duration; and advancing or retarding, by the intake and/or exhaust CVVD devices, the current opening timing of the intake and exhaust valves while simultaneously retarding or advancing the current closing timing of the intake and exhaust valve by a predetermined value based on the target opening duration.

A method for controlling intake and exhaust valves of an engine may include: determining, by a controller, a target opening duration of the intake and exhaust valves according to a control region determined based on an engine load and an engine speed; modifying, by an intake continuous variable valve duration (CVVD) device and by an exhaust CVVD device, opening and closing timings of the intake valve and exhaust valve based on the target opening duration of the valves; and advancing or retarding, by the intake and/or exhaust CVVD devices, the opening timing of the intake and exhaust valves while simultaneously retarding or advancing the closing timing of the intake and exhaust valve by a predetermined value based on the target opening durations. In particular, the controller classifies five control regions based on the engine load and speed.