A fuel injection controller includes a discharge switch that turns ON/OFF energization of a first energization path from a boost power source of a second booster circuit when a second control IC energizes a second solenoid, a first detection element that detects a value that depends on an energization state of the discharge switch, a constant current switch that turns ON/OFF energization of a second energization path from a power source voltage that outputs a lower voltage than a boost power source voltage when the second control IC energizes the second solenoid, a second element that detects a value that depends on an energization state of the constant current switch, and an energization path controller that switches energization to the second solenoid.

A lower limit setting portion of a fuel pump control system sets a lower limit value depending on an engine operating mode. For example, it sets a duty ratio of 0% as the lower limit value, when the engine operating mode is in a STOP mode in a turned-on condition of an ignition switch. A duty-ratio calculating portion carries out a feedback control in order that an actual fuel pressure comes closer to a target fuel pressure by use of the lower limit value and calculates a duty ratio for driving a fuel pump by the feedback control. An abnormal condition determining portion determines an abnormal condition based on the duty ratio and pump current. The abnormal condition determining portion further determines based on a remaining fuel amount whether the abnormal condition is caused by a disconnection or whether the abnormal condition is caused by an idling operation of the fuel pump due to fuel shortage.

Because the relationship of the fuel injection quantity to a designated injection period differs in a half-lift region and a full-lift region, the purpose of the present invention is to bring the flow rate characteristics of an intermediate-lift region close to the flow rate characteristics of the full-lift region and improve the controllability of small fuel injection quantities. Provided are a peak current supply period in which a valve body of a fuel injection valve causes the magnetic force necessary for a valve-opening action to be generated, and a lift quantity adjustment period in which, after the peak current supply period, a current lower than the peak current is passed for a prescribed period; further provided is a current interrupt period in which a drive current is rapidly lowered before the lift quantity adjustment period.

A control apparatus of a valve opening/closing timing control mechanism, configured by including driving side and driven side rotating bodies; a stopper unit; and an electric motor, includes: a phase controller controlling an electric motor to reduce, when a target phase is set, a deviation between the target phase and a current first actual phase and reducing power to be supplied to the electric motor as the deviation decreases; and a control target setting unit setting a first target phase displaced to a side of the first actual phase in an operation direction where the deviation is reduced when the target phase is set to a most retarded or most advanced angle phase, in which the phase controller executes a first phase control of reducing a deviation between the set first target phase and the current first actual phase.

Methods and systems are provided for monitoring and controlling a cylinder valve deactivation mechanism. In one example, a method may include sending a lower command signal to a cylinder deactivation valve control (CDVC) system without actuating a cylinder valve transition, determining an impedance of a solenoid of the CDVC system while sending the lower command signal, and actuating the cylinder valve transition responsive to the determined impedance by sending a higher command signal to the CDVC system. In this way, the cylinder valve transition is performed when the impedance is high enough to prevent over-current.

Methods and systems are provided for an EGR valve diagnostic. In one example, a method may include actuating an EGR valve between first and second positions. The method may further includes determining one or more characteristics of the EGR valve during the diagnostic to determine if an EGR valve cleaning is desired.

A method for controlling an engine system, may include a water injection operation of injecting water into an intake system of an engine through a water injector of a water injection system in a first operating condition of the engine in which water injection is required, a compressed air injection operation of injecting compressed air into the intake system through a purge circuit of the water injection system in a second operating condition of the engine in which compressed air injection is required, and a water injection stop operation of stopping the water injection of the water injection system in a third operating condition of the engine in which water injection stop is required.

When a waste gate valve (7) is forcibly fully closed for learning control at the time of start, the drive force of an electric actuator (20) is initially set to a large first level, and when a predetermined position (L1) immediately before seating is reached, the driving force is reduced to a second level. As a result, a valve body (7a) is gently seated. When a predetermined time (TM1) passes, the driving force is increased to a third level. Consequently, the electric actuator (20) presses the valve body (7a) onto a seat surface (34a) while displacing a spring member (37). As a result, a reliable sealability is obtained.

A Purge Control Solenoid Valve (PCSV) control method for preventing malfunction may include: starting-up by a starting motor a crankshaft of an engine, and opening PCSV by a duty-control, wherein in the starting-up step, the PCSV is opened to eliminate foreign substances stained on the PCSV.

To protect a switching element to be used in a boost circuit for an in-cylinder injection type internal combustion engine or the like from damage caused by overheating without using a temperature detection element. In a control circuit that switches a switching element between a conductive state and a non-conductive state, the switching element is controlled or a temperature of the switching element is estimated based on a potential difference between an input terminal and an output terminal of the switching element and a voltage applied to a control terminal of the switching element in the conductive state.