Proposed is a method for open-loop and closed-loop control of an internal combustion engine (1), the rail pressure (pCR) being controlled via a low pressure-side suction throttle valve (4) as the first pressure-adjusting element in a rail pressure control loop. The invention is characterized in that a rail pressure disturbance variable is generated to influence the rail pressure (pCR) via a high pressure-side pressure control valve (12) as the second pressure-adjusting element, by means of which fuel is redirected from the rail (6) into a fuel tank (2).

A method and an apparatus for monitoring a temperature of a coil wire of a solenoid valve are provides. An actuation signal has actuation intervals which follow one another is used in this case, wherein a start pulse, which causes an increase in current in the coil wire of the magnet coil and has a prespecified pulse duration, and a pulse sequence, which follows the start pulse and has a duty cycle, are provided in each actuation interval. The current intensity of the current flowing through the coil wire of the solenoid valve is measured at two different times during the increase in current, and the current gradient is subsequently calculated from the measured current intensities. A prespecified threshold value for the current gradient is then compared with the calculated current gradient.

A method is provided for determining the velocity of a pintle assembly in a solenoid fuel injector during a closing stroke of the pintle assembly, such that a braking step is performed during the closing stroke, which includes operating an injector driver with a current regulator to establish a braking current in the solenoid coil. The velocity of the pintle assembly is derived from the duty-cycle of the current regulator during the braking step. A method of operating a solenoid fuel injector, in particular for gaseous fuel, using the so-determined pintle velocity is also provided.

An apparatus and method of controlling an electronic continuously variable valve timing (CVVT) is provided. The apparatus includes a sensor disposed in a motor facing a reducer and an intelligent motor controller. The sensor determines a rotation speed of a first and second projection of a first and second rotation member and generates a sensing signal that corresponds to an output waveform of each rotation speed and inputs the signal to an intelligent motor controller coupled to the motor. The intelligent motor controller receives the signal and separates a crank shaft and cam shaft position signal. The signals are compared to detect an actual phase angle of the suction or exhaust valve. A phase deviation between the detected, actual and predetermined target phase angle is calculated.

A method and system for actively controlling the fuel pressure in the fuel rails of a fuel injection system is disclosed for providing wideband fuel rail control. An active pressure control circuit controls the pressure control valve over the entire range of engine operating conditions and in the frequency domain. Implementation of a closed-loop feedback control is effective for attenuating fuel pressure fluctuations in the fuel rail assembly.

Various methods for determining a holding current based on a pressure differential across a wastegate valve are provided. In one example, a method of operating a wastegate comprises determining a holding current with which to hold a wastegate valve at a desired position, the holding current determined based on a pressure differential across the wastegate valve.

Methods and devices are described for performing engine diagnostics during skip fire operation of an engine while a vehicle is being driven. Knowledge of the firing sequence is used to determine appropriate times to conduct selected diagnostics and/or to help better interpret sensor inputs or diagnostic results. In one aspect, selected diagnostics are executed when a single cylinder is fired a plurality of times in isolation relative to a sensor used in the diagnosis. In another aspect, selected diagnostics are conducted while the engine is operated using a firing sequence that insures that no cylinders in a first cylinder bank are fired for a plurality of engine cycles while cylinders in a second bank are at least sometimes fired. The described tests can be conducted opportunistically, when conditions are appropriate, or specific firing sequences can be commanded to achieve the desired isolation or skipping of one or more selected cylinders.

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 closed loop control system for a fuel pump based on characteristics of speed, pressure, and current. The pressure generated by the pump system is increased at the point in time when the pump system is working against a dead head system (i.e., coasting) to a level that a calibration valve is opened to a determined working point. By measuring the characteristic phase current as a function of the speed, the characteristic is able to be compared, with the pre-calibrated value of the hardware to perform an error compensation algorithm. The error compensation is overlaid with the standard pressure characteristic as a function of speed and phase current, and uses the pre-calibrated opening pressure value (i.e., the inflection point) of the calibration valve and/or in addition the change of the speed to the initial (first calibration), or to a sliding average therefrom.

A fuel injection controller includes an increase control portion applying the boost voltage to the coil to increase a coil current to a first target value, and a constant current control portion applying a voltage to the coil to hold the coil current to a second target value. A threshold is an energization time period that is necessary to reach a boundary point between a seat throttle area of a property line and an injection-port throttle area of the property line from an energization start time point. An initial-current applied time period is from the energization start time point that the boost voltage starts to be applied to the coil to a time point that the coil current is decreased to the second target value. The increase control portion controls the coil current such that the initial-current applied time period is less than the threshold.