A diagnostic device incorporates a processor and a memory and diagnoses a failure related to a fuel injection system for an engine whose air-fuel ratio of is feedback-controlled. The diagnostic device includes a calculation unit which calculates a corrected value of a fuel injection amount according to a difference between a target value and a measured value of the air-fuel ratio. The diagnostic device includes a setting unit which sets a mask period in which a failure diagnosis is suspended, according to the corrected value upon switchover of a fuel injection mode. The diagnostic device includes a diagnostic unit which does not carry out the diagnosis in the mask period and carries out the diagnosis outside the mask period.

A method for detecting defective injectors includes operating an internal combustion engine in an idling mode and deactivating mixture control of the internal combustion engine. The method also includes switching off selectively each injector of the respective injection group, detecting the change in the characteristic value when the respective injector is switched off, and checking a fault criterion. The fault criterion is satisfied when the change in the characteristic value for the respective switched-off injector exceeds or undershoots a predetermined amount. The method also includes detecting a defect in the respective injector in response to the fault criterion being satisfied.

A vaporized fuel treating device having a canister that is configured to adsorb vaporized fuel in a fuel tank and to feed the adsorbed vaporized fuel to an engine may include a pressure sensor that is configured to periodically detect an inner pressure of the fuel tank, and a pressure sensor failure determination device that is configured to determine that the pressure sensor has failed when a change of the inner pressure detected by the pressure sensor in a unit of time is not less than a predetermined pressure value that is greater than a maximum value of possible pressure changes within the fuel tank.

A method for checking a parameter correlating with a pressure in a pressure-dependent fluid delivery system, the fluid delivery system having: a current-controlled electric motor controlled by a motor controller, and a fluid pump driven by the electric motor, includes: determining a rotational speed of the electric motor; determining a current of the electric motor, by reading out an activation current of the motor controller; calculating a pressure value as a function of the rotational speed and the current of the electric motor; and comparing the calculated pressure value with the parameter.

The fuel pressure sensor abnormality diagnosis apparatus diagnoses that a fuel pressure sensor is abnormal in the case where, because a state where a detected value of the fuel pressure sensor is less than a target value occurs, a fuel discharge amount of a fuel pump is increased, and as a result, the fuel discharge amount reaches its maximum amount, and even if a predetermined period has elapsed since the fuel discharge amount reaches its maximum amount, the detected value is less than the target value.

A filter monitoring system and method are described. The filter monitoring system includes a remote telematics system, and a data link between the remote telematics system and an onboard telematics system. The remote telematics system is configured to receive, via the data link, an indication of a pressure drop across a filter cartridge of the filtration system from the onboard telematics system, determine a first value indicative of a remaining filter life of the filter cartridge of the filtration system, determine a second value indicative of a remaining filter life of the filter cartridge that is determined in a different manner than the first value, compare the first value to the second value to determine which value indicates a least amount of life remaining for the filter cartridge, and transmit an indication of the least amount of life remaining for the filter cartridge based on the comparison.

A method determines an inflection point OP of a parameter profile i, n which is representative of a component tolerance and a state of wear of a fuel pump. The fuel pump is provided for a fuel supply system for use in a device equipped with an internal combustion engine. The device being a passenger car, utility vehicle and/or a stationary or mobile power generator.

A method to control a road vehicle during a slip of the drive wheels, which are caused to rotate by an internal combustion engine provided with a plurality of cylinders arranged in two banks, and with a plurality of fuel injectors each injecting fuel into a corresponding cylinder. The control method comprises the steps of: detecting a slip of at least one drive wheel; and controlling the internal combustion engine, only during a slip of at least one drive wheel, with a signalling law, which causes the internal combustion engine to work in an abnormal manner so as to generate an abnormal vibration and/or an abnormal noise, which can be perceived by the driver. The internal combustion engine has two twin control units, each of which is associated with a corresponding bank, controls all and the sole injectors of its own bank and actuates the signalling law completely independently of and autonomously from the other control unit.

An engine fuel delivery system includes a fuel pump having a pumping chamber to increase fuel pressure and a closeable inlet valve, and a fuel rail to communicate pressurized fuel received from the fuel pump to at least one engine cylinder. The engine fuel delivery system also includes a controller programmed to issue a control signal to periodically close the inlet valve to generate a setpoint fuel pressure within the pumping chamber. The controller is also programmed to adjust a control signal gain value in response to deviation in an outlet fuel pressure relative to the setpoint fuel pressure. The controller is further programmed to issue a warning message in response to the control signal gain being adjusted by more than a predetermined threshold from a calibrated gain value.

A fuel level sensor detects the level of fuel in a fuel tank. A level signal detected by a float does not change in a full dead zone and an empty dead zone. During normal fuel consumption, the level signal changes according to the consumption amount. Thus when an electronic control unit, or ECU, detects that the fuel level sensor is operating normally, the ECU resets a fuel consumption amount. However, when a small quantity of fuel is supplied, the fuel consumption amount is not reset, and a measurement error may occur during failure detection. Accordingly, the ECU corrects a failure threshold value to avoid misdiagnosing a failure.