A diagnosis device for an evaporated fuel processing device includes: a pump arranged to pressurize or depressurize a system including the fuel tank and the canister; at least one pressure sensor arranged to sense a pressure within the system; and a fuel temperature sensor arranged to sense a temperature of a fuel within the fuel tank, the diagnosis device being configured to select a first leakage diagnosis using a positive pressure or a negative pressure existing within the fuel tank, or a second leakage diagnosis using a forcible pressurization or a forcible depressurization by the pump, based on a temperature difference between a fuel temperature at a start of driving, and a fuel temperature after an end of the driving, with respect to a request of a leakage diagnosis.

A method and a system for detection of torque deviations of an engine (101) in a vehicle (100). A measurement (201) is made of actual measured values D.sub.act related to a behavior of at least one parameter which is related to an actual torque M.sub.eng.sub._.sub.act delivered by the engine (101). This actual torque M.sub.eng.sub._.sub.act is delivered here by the engine (101) in consequence of a torque M.sub.eng.sub._.sub.req demanded from the engine (101). A comparison (202) is then made of the actual measured values D.sub.act which are related to the behavior of the at least one parameter with previously determined measured values D.sub.ref of correspondingly at least one respective parameter related to the actual torque M.sub.eng.sub._.sub.act. The previously determined measured values D.sub.ref will here have been determined during normal operation of the vehicle (100). Detection is then made of whether the actual measured actual torque M.sub.eng.sub._.sub.act deviates from the demanded torque M.sub.engj-eq. The detection is based here on the comparison of the actual measured values D.sub.act with the previously determined measured values D.sub.ref.

Methods and systems are provided for reducing lean air-fuel ratio excursions due to degradation of a port injector while fueling an engine via each of port and direct injection. During a PFDI mode of engine operation, responsive to an indication of port injector degradation, such as due to circuit or injector power issues, intake airflow is limited by reducing the opening of an intake throttle. Air flow is limited to be based only on the direct injected fuel fraction, and independent of the commanded port injected fuel fraction.

An engine control apparatus and method in which when an injector malfunction is determined based on a difference in variation of angular velocity of a crankshaft between a plurality of cylinders of a vehicle engine, determining whether the injector malfunctions by avoiding the time when the driving torque of an air compressor is applied or at the time when the influence thereof is reduced, thereby preventing the erroneous determination of whether the injector malfunctions from occurring due to the driving torque of the air compressor connected to the vehicle engine.

After a system-off state has continued for a preset, time period since a system-off operation, on satisfaction of abnormality diagnosis prerequisites including a condition that a warm-up determination parameter indicating a degree of warm-up of an engine at a system-off time is equal to or greater than a predetermined value, characteristic abnormality diagnosis is performed to determine whether a characteristic abnormality occurs in a fuel pressure sensor. For a time period from a system-on operation to a system-off operation, the warm-up determination parameter is incremented when the engine is in operation, while being decremented after satisfaction of a predetermined condition when the engine is not in operation.

A method for identifying faulty components of a fuel injection system is disclosed, wherein a secondary injection is performed individually by each injector during a test routine, after the secondary injection several predefined parameters of the fuel injection system are determined, and a combined assessment of the determined parameters is used to draw conclusions about whether or not components of the fuel injection system are faulty.

An alarm system is used for a vehicle including a fuel pump and an engine. The alarm system includes a measuring device, a computing device and a warning device. The measuring device is used to read a current rotation speed of the engine and respectively measures a plurality of running times of a plurality of rotation speed values of the current rotation speed. The computing device calculates a plurality of consuming times of the fuel pump corresponding to the rotation speed values according to the running times of the rotation speed values, respectively. When an accumulating consuming time accumulated by the consuming times reaches a default critical value, the warning device generates a warning message.

A method according to the invention for checking the plausibility of the function of a pressure sensor in an injection system of an internal combustion engine includes acquiring a calibrated actuation profile, by which peak current values for opening at least one electrically actuatable injection valve are assigned to existing internal pressures. An existing internal pressure is measured in the form of an actual sensor pressure value by the pressure sensor. The method includes obtaining the electrical peak current value corresponding to the measured sensor pressure value from a calibrated actuation profile, such that the corresponding electrical peak current value acquired in this way is applied to the injection valve. Subsequently, an opening state of the injection valve is monitored in reaction to the applied electrical peak current value, and a functional state of the pressure sensor is assigned as a function of the opening state of the injection valve.

A method for predefining a current through a solenoid coil of a solenoid valve, a closing point in time of the solenoid valve being detected with the aid of a sensor, a sensor value being monitored, and, when a premature closing of the solenoid valve is identified based on the monitored sensor value, the current through the solenoid coil of the solenoid valve is increased.

A method for regulating a fuel delivery system without a pressure sensor. The fuel delivery system has a fuel delivery pump, an electric motor, and an evaluation unit. The fuel delivery pump is driven by the electric motor, which is actuated using control variables such that a prespecifiable fuel delivery is achieved. At least two different submethods are executed for ascertaining control variables, which are ascertained in the respective submethod and are supplied to an evaluation unit. The control variables are evaluated regarding their plausibility in the evaluation unit and the electric motor is actuated based on the ascertained control variables from only one or a plurality of submethods.