The vehicle is a hybrid vehicle capable of traveling using motive power of at least one of an engine and a motor generator. The vehicle includes: a fuel pump; an injection valve injecting fuel supplied from the fuel pump to the engine; a fuel pressure sensor detecting a supply pressure of the fuel generated by the fuel pump; and an engine ECU. The engine ECU performs a fuel pressure increasing process of increasing the supply pressure of the fuel generated by the fuel pump, and conducts a fault diagnosis of the fuel pressure sensor based on a value detected by the fuel pressure sensor during the fuel pressure increasing process. The engine ECU conducts the fault diagnosis of the fuel pressure sensor in a case where the engine is being stopped and a vehicle speed is higher than a threshold value.

An exhaust gas control apparatus includes a first catalyst, a filter, and an electronic control unit. The electronic control unit is configured to alternately execute lean control and rich control multiple times. The lean control is control for, over a period longer than a period from when a target air-fuel ratio is set to a predetermined lean air-fuel ratio until an air-fuel ratio of exhaust gas flowing out from the first catalyst becomes greater than the stoichiometric air-fuel ratio, setting the target air-fuel ratio to the predetermined lean air-fuel ratio. The rich control is control for, over a period longer than a period from when the target air-fuel ratio is set to a predetermined rich air-fuel ratio until the air-fuel ratio of exhaust gas flowing out from the first catalyst becomes smaller than the stoichiometric air-fuel ratio, setting the target air-fuel ratio to the predetermined rich air-fuel ratio.

A vehicle includes an engine air intake having a humidity sensor, and a system having a nozzle positioned in the air intake and fluidly connected to a reservoir. The vehicle has a controller configured to activate the system to deliver fluid from the nozzle into the intake while the engine is inoperative and generate a diagnostic code in response to a change in humidity measured by the sensor being less than a threshold value. A method of controlling a vehicle includes measuring a baseline humidity (H1) using a humidity sensor in an air intake of an engine, and controlling a misting system to mist fluid from a reservoir into the air intake and adjacent to the humidity sensor while the engine is inoperative. The method measures a post-fluid delivery humidity (H2) using the humidity sensor, and generates a diagnostic code based on a comparison of H1 and H2.

Various embodiments include a method for operating an internal combustion engine wherein the compression is variably adjusted comprising: checking a sensor signal indicative of a compression of the engine; checking the plausibility of the signal by: ascertaining a series of corresponding values of the signal and values of the actuating variable; determining a mathematical relationship between the signal and the variable based on the series; determining a deviation between the relationship and a predetermined characteristic relationship; and determining the signal is plausible when the determined deviation is lower than a predetermined threshold value; and if the determined deviation is higher than the predetermined threshold value, adjusting operation of the internal combustion engine.

In a control device for an exhaust gas sensor, a deterioration determination section determines whether the magnitude of a signal outputted from a second cell has exceeded a threshold to thereby determine whether a first cell has deteriorated. A threshold setting section variably sets the threshold depending on a concentration of the oxygen in the exhaust gas.

In a method of operating a drive device, a probe temperature of an exhaust gas exhaust gas probe in an exhaust tract is measured, as the exhaust gas probe is heated by a probe heater. A temperature growth value representative of an increase in temperature of the exhaust gas probe is determined during heating of the exhaust gas probe, and the presence of a defect of the probe heater is recognized, when the temperature growth value deviates from an input value.

A method of detecting a defeat device includes: determining turbo operation when a turbocharger of a vehicle is operated; determining flow rate of the air to be applied to an intake manifold wherein it is determined whether which flow rate out of a first flow rate of the air passing through a throttle valve and a second flow rate of the air measured by a hot-film air mass flow (HFM) sensor is used as the flow rate of the intake manifold; determining whether pressure in the intake manifold is in a normal range based on the flow rate of the intake manifold; and determining that the defeat device is installed if it is determined that the pressure in the intake manifold is not in the normal range and storing information of the defeat device.

The abrupt cessation or run-away of a combustion engine may damage the combustion engine and pose a safety hazard to the surrounding environment. The combustion engine operational mode may be controlled, regulated or maintained by regulating the combustion mixture of the combustion engine. The oxidizer flow, a material or both of the combustion mixture may be regulate to create or form a combustion material that is outside a combustible range such that the combustion engine is placed or maintained in a spin-down operational mode. The material added to the combustion mixture may include a combustible, non-combustible, oxidizer, or exhaust material. A brake may also provide a secondary mechanism to maintain or place the combustion engine in a spin-down mode.

A control device of a general-purpose engine which can continue operation of a working machine even when an operation management unit of the working machine has failed. The control device includes an engine control unit that controls the general-purpose engine based on a command from the operation management unit managing an operating state of the working machine, a communication interface for communicating with an external device; a management program acquisition unit that acquires a management program that is used by the operation management unit to manage the operating state, from the external device through the communication interface and stores the acquired management program in a storage medium, and an operation management substitute unit that manages the operating state of the working machine in place of the operation management unit in accordance with the management program when a failure of operation management unit is detected.

Methods and systems are provided for rationalizing an engine knock sensor. In one example, a method may include, responsive to an indication of an engine knock event, correlating an output of the engine knock sensor with an output of an on-board microphone to determine degradation of the engine knock sensor. By rationalizing the engine knock sensor against another on-board sensor (e.g., the on-board microphone), diagnostic fidelity may be increased.