Methods and systems are provided for conducting a fuel tank pressure transducer rationality test diagnostic procedure in vehicles with sealed fuel tanks. In one example, vehicle-to-vehicle (V2V) or vehicle-to-infrastructure-to-vehicle (V2I2V) technology may be utilized to obtain fuel tank pressure transducer data from a select crowd of vehicles, where the select crowd may be based on the vehicles in the select crowd experiencing similar ambient temperature and weather as the vehicle being diagnosed. In this way, FTPT data from vehicles in the select crowd may be compared to FTPT data in the vehicle being diagnosed, in order to indicate whether the FTPT in the vehicle being diagnosed is functioning as desired, where such a diagnostic can be performed without unsealing the fuel tank on either the vehicle being diagnosed or the vehicles in the select crowd, and which may thus reduce undesired evaporative emissions.

Methods and systems are provided for a diagnostic of a pressure sensor. In one example, a method includes bypassing one or more vapor canisters and determining a condition of the pressure sensor based on feedback from a hydrocarbon sensor.

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.

Embodiments of the present invention provide a method and a system for controlling fuel supply of a dual-fuel vehicle. The method includes: detecting an operation status of a pressure sensor by an electronic control unit, when an engine is at a gas state; receiving a pressure signal of the pressure sensor by the electronic control unit, when the pressure sensor works properly, the pressure signal indicating internal pressure of a gas tank; and controlling the engine to switch to fuel state by the electronic control unit, when the duration time of the internal pressure of the gas tank less than or equal to a predetermined pressure is greater than or equal to a predetermined time. The method can accurately control switching states according to the remainder of the gas in the gas tank, therefore avoid the engine frequent gas-fuel.

A fuel pressure sensor diagnosis device includes an electronic control unit configured to drive a fuel supply device during electric traveling of a hybrid vehicle, to perform determination as to whether an output of a fuel pressure sensor is within a normal range after driving of the fuel supply device is started, and to perform a diagnosis to determine whether a malfunction has occurred in the fuel pressure sensor based on a result of the determination, the normal range being an assumed range of the output of the fuel pressure sensor in a case where the fuel pressure sensor normally functions and the fuel supply pressure is a prescribed upper limit pressure.

An evaporated fuel processing device that includes a pressurizing pump configured to pressurize gas in the vapor passage downstream of the closing valve toward the closing valve; a first pressure sensor configured to detect a pressure in the fuel tank directly or indirectly, and/or a second pressure sensor configured to detect a pressure in the vapor passage downstream of the closing valve directly or indirectly. When the closing valve moves toward an open side in the closed state with the pressurizing pump pressurizing the gas in the vapor passage downstream of the closing valve toward the closing valve, the controller may specify a valve-opening-start position based on the pressure detected by the first pressure sensor and/or the pressure detected by the second pressure sensor, wherein the valve-opening-start position is a position where the closing valve transitions from the closed state to the opened state.

After an ECU is activated by turning a key switch on, if a total intake air quantity, which is indicative of the engine temperature immediately before turn-off of the key switch, exceeds a set intake air quantity indicative of a full warm-up determination temperature, and a soak time exceeds a set key-off time, it is determined that the condition for executing a diagnosis of a fuel pressure sensor is satisfied.

The present disclosure relates to internal combustion engines and the teachings thereof may be embodied in methods and apparatus for detecting a malfunctioning rail pressure sensor. Some embodiments may include a method for detecting a malfunctioning rail pressure sensor comprising: delivering an analog output signal characterizing the rail pressure to a control unit; generating a differential rail pressure signal as a digital output signal; delivering the differential rail pressure signal of the rail pressure sensor to the control unit; analyzing the analog output signal and the differential rail pressure signal in the control unit; and detecting a malfunctioning rail pressure sensor based on the analysis by the control unit.

A device executes a power limiting process when the number of pressure sensors determined to be normal in a second determination process made by a second processing unit is smaller than or equal to one. When only one pressure sensor is determined to be normal through the second determination process, and when that pressure sensor and a pressure sensor connected to only a first processing unit are determined to be normal in a first determination process made by the first processing unit, a process associated with fuel injection based on a detected value of the pressure sensor determined to be normal in the second determination process is executed, and a degree of limiting engine power through the power limiting process is reduced as compared with when both the pressure sensors are determined to be abnormal in the first determination process.

A driving control device for a fuel pump may include a valve-opening-rate calculating unit and a driving control unit. The valve-opening-rate calculating unit may be configured to calculate an injector valve opening rate. The injector valve opening rate may be an injection time of an injector per unit time. The driving control unit may be configured to set a voltage duty ratio of a driving voltage that should be applied to the fuel pump that supplies fuel in a fuel tank to a fuel pipe communicating with the injector. The driving control unit may be further configured to set the voltage duty ratio to a value that is proportional to the injector valve opening rate calculated via the valve-opening-rate calculating unit.