A device and a method for checking switch-off paths in control units of internal combustion engines during ongoing engine operation.

An injection control device of capable of correcting an energization time even in an S/N non-guaranteeable situation includes: an energization controller calculating an energization time correction amount based on an area correction performed by an energization time correction amount calculator regarding electric current flowing in a fuel injection valve when the fuel injection valve is electrically driven for injecting fuel; and an energization instruction time calculator correcting an energization instruction time for fuel injection in a next cycle and thereafter by using the energization instruction time correction amounts in or before a current cycle.

Various methods and systems are provided for diagnosing a condition of a fuel injector of an engine. In one example, a method for an engine includes injecting a first pulse of fuel as a first pilot injection into a first subset of cylinders of a plurality of engine cylinders, where the first pilot injection precedes a primary injection of fuel into the first subset of cylinders by a duration; correlating a first response in an engine operating parameter to the first pilot injection; and adjusting the primary injection of fuel into the first subset of cylinders based on the first response. In one example, the first pilot injection precedes the primary injection by a predefined short duration and the primary injection of fuel is adjusted within a predefined or preset upper limit and lower limit.

A device and a method for checking switch-off paths in control units of internal combustion engines during ongoing engine operation.

A method for monitoring an engine cylinder in an internal combustion engine includes, for each engine cycle, detection of the ionisation current generated in the cylinder in a predetermined time interval of a combustion cycle, generation of a signal representing the ionisation current and comparing a maximum value of the signal with a threshold value. Successively, the value of one or more parameters associated with the signal can be changed with respect to an equal number of corresponding reference values when the maximum value of the signal exceeds the threshold value, to reduce the maximum value of the signal in the time interval of a successive combustion cycle. The presence of water in the cylinder can be determined when the maximum value of the signal exceeds the threshold value for a predetermined first number of combustion cycles occurring within a predetermined period of time.

The present disclosure provides a method for learning emergency injection correction of an injector for preventing misfire. A misfire rate in a multi-stage injection mode is monitored, and it is controlled to be forcibly switched to a single injection mode when the misfire rate by the monitoring is equal to or greater than a specific value, such that injector injection correction learning is performed according to a learning entry condition. Accordingly, it is possible to reduce the deviation between cylinders by the sufficient injection amount deviation correction learning, thereby preventing misfire of the injector.

Methods and systems are provided for a fuel system. In one example, a method includes comparing a resistance of a solenoid coil of a direct injector to a threshold resistance. The method further includes selecting one of a transient or a steady-state pressure-based injector balancing (PBIB) model in response to the comparison.

An injector diagnosis device 1 includes: an engine sound model generator 14 configured to generate a normal engine sound model and an abnormal engine sound model based on the number of cylinders of the engine and a combustion pattern of the engine; an operating sound obtainment unit 12 configured to obtain the operating sound of the engine operating with the combustion pattern; a frequency characteristics calculation unit 13 configured to calculate the frequency characteristics of the operating sound obtained by the operating sound obtainment unit 12; and an injector diagnosis unit 15 configured to diagnose whether or not the injectors have a failure based on the frequency characteristics of the operating sound which is calculated by the frequency characteristics calculation unit 13, and the normal engine sound model and the abnormal engine sound model which is generated by the engine sound model generator 14.

A method for operating an injector on an internal combustion engine includes the steps of: introducing a fuel into a combustion chamber of the internal combustion engine by way of the injector; capturing, for a plurality of injection events, a wear value for the injector; assigning each respective one of the wear value that is captured to a respective one of a plurality of wear value classes; determining, for each of the plurality of wear value classes, a class frequency of a plurality of the wear value that are captured and assigned to a corresponding one of the plurality of wear value classes; calculating, based on a plurality of class frequencies of the plurality of wear value classes, a total wear value for the injector; and evaluating a condition of the injector based on the total wear value.

A fuel pressure control system for a fuel supply system of an injector of an engine includes: a booster pump for increasing a high-pressure system fuel pressure; a pressure reducing valve for reducing the high-pressure system fuel pressure; and a control device for controlling the booster pump and the pressure reducing valve. The control device includes a valve opening necessity determination unit for the pressure reducing valve. The control device executes a valve opening control for opening the pressure reducing valve. The control device further includes a restriction execution unit for performing a valve opening restriction control in the valve opening control to prevent a pressure exceeding a predetermined target portion threshold pressure from being applied to a target portion.