Provided are a novel exhaust pipe temperature estimation device and a sensor heater control apparatus for an exhaust gas sensor using the same that accurately estimates an estimation exhaust pipe temperature when an internal combustion engine is stopped and restarted in response to a change of an environmental condition of the internal combustion engine and controls an operation of a sensor heater based on the estimated estimation exhaust pipe temperature. Thus, at least first correction information Tz based on a change of an exhaust pipe temperature and an elapsed time at stop, second correction information Ty based on a change of an internal combustion engine temperature at the stop of the internal combustion engine, and third correction information Tz based on a change of a cooling degree due to outdoor air during stop from the stop to restart are obtained, an estimation exhaust pipe temperature at the stop is corrected using at least one or more pieces of the correction information at restart of the internal combustion engine to estimate an estimation exhaust pipe temperature at the restart, and an estimation exhaust pipe temperature during an operation of the internal combustion engine thereafter is obtained using the estimation exhaust pipe temperature as an initial value, and further, a heating operation of a sensor heater is started when the estimation exhaust pipe temperature becomes equal to or higher than a predetermined value.

A dual fuel engine control system includes a pressure sensor, and an electronic control unit coupled with the pressure sensor and structured to receive cylinder pressure data indicative of cylinder over-pressurization, and to switch the system to a limited gas-to-liquid substitution mode based on the cylinder pressure data indicative of cylinder over-pressurization. The electronic control unit is further structured to return the system to a normal gas-to-liquid substitution mode, receive cylinder pressure data indicative of cylinder over-pressurization after returning the system to the normal gas-to-liquid substitution mode, and responsively output a gas substitution fault signal.

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.

A dual fuel engine control system includes a pressure sensor, and an electronic control unit coupled with the pressure sensor and structured to receive cylinder pressure data indicative of cylinder over-pressurization, and to switch the system to a limited gas-to-liquid substitution mode based on the cylinder pressure data indicative of cylinder over-pressurization. The electronic control unit is further structured to return the system to a normal gas-to-liquid substitution mode, receive cylinder pressure data indicative of cylinder over-pressurization after returning the system to the normal gas-to-liquid substitution mode, and responsively output a gas substitution fault signal.

Disclosed are a method and apparatus for diagnosing a fault in a CVVD system. The method includes collecting information necessary to determine whether a fault diagnosis mode entry condition of the CVVD system is satisfied, determining whether the fault diagnosis mode entry condition is satisfied based on the collected information, calculating prediction duration corresponding to a current engine RPM and manifold pressure when the fault diagnosis mode entry condition is satisfied, calculating current duration based on an output value of a motor sensor for detecting the RPM of the duration control motor of the CVVD system, comparing the manifold pressure-based prediction duration D1 with the sensor output-based duration D2, and determining an error of the motor sensor or whether the CVVD system has failed by comparing a duration difference cumulative value, that is, a cumulative value of difference values between the D1 and D2, with a previously stored threshold.

An abnormality diagnosis system of an air-fuel ratio sensor is provided with an exhaust purification catalyst, an upstream side air-fuel ratio sensor which is provided at an upstream side of the exhaust purification catalyst, a downstream side air-fuel ratio sensor which is provided at a downstream side of the exhaust purification catalyst, and a diagnosis device which uses the outputs of these air-fuel ratio sensors as the basis to diagnose abnormality of the downstream side air-fuel ratio sensor.

A control device for an internal combustion engine includes an intake-side variable valve timing mechanism and a controller. The intake-side variable valve timing mechanism is configured to continuously advance or retard a phase of a cam that actuates an intake valve. The controller is configured to actuate the intake-side variable valve timing mechanism toward a retardation side and position the intake-side variable valve timing mechanism at a prescribed position, and execute fail-safe control on the basis of a signal from a cam position sensor instead of a signal from the crank position sensor, when it is determined that there is a failure in a crank position sensor of the internal combustion engine.

An engine system includes an engine, an atmospheric pressure sensor, an intake pressure sensor, and an electronic control unit. The electronic control unit is configured to execute atmospheric pressure learning for learning a relation between atmospheric pressure and an intake air amount of the engine based on the atmospheric pressure detected by the atmospheric pressure sensor, and execute fuel injection control of the engine using an initial value of an intake air amount model obtained based on the atmospheric pressure learning. The electronic control unit is configured to execute the fuel injection control of the engine using an initial value of the intake air amount model obtained based on the intake pressure detected by the intake pressure sensor, when rotational speed of the engine is less than a specified rotational speed at start of the fuel injection control of the engine.

A vehicle environmental compliance system includes: an onboard diagnostic (OBD) tool configured to obtain OBD data from a vehicle's onboard diagnostics; an application for storage on a mobile computing device in communication with the OBD tool, the application configured to process the OBD data to form processed OBD data; a compliance center or server for receiving the process the OBD data from the application, the compliance center or server configured to further process the processed OBD data to form further processed OBD data; and wherein one of the processed OBD data or the further processed OBD data includes a result of OBD data subjected to a compliance evaluation routine, and wherein the system maintains a triggering algorithm that determines when the compliance evaluation routine is performed.

A humidity measuring device is located at a vehicle and includes a humidity sensing unit configured to detect a humidity of an air, a humidity information acquisition unit configured to acquire a variation quantity of the humidity with time or a humidity information that is information relating to the variation quantity of the humidity with time, a vehicle information acquisition unit configured to acquire a vehicle information including at least one of information indicating a driving state of the vehicle or information of an attachment environment of the humidity sensing unit, a threshold setting unit configured to set a threshold for determining whether water is adhered to the humidity sensing unit, based on the vehicle information, and an adhesion determination unit configured to compare the humidity information with the threshold and to determine that water is adhered to the humidity sensing unit when the humidity information reaches the threshold.