An abnormality diagnosis device of an in-cylinder pressure sensor is provided. The device carries out a performance determination in which a performance quality of the sensor is determined based on an electric signal inputted from the sensor. The device carries out a first determination in which the performance determination is performed at a given timing, a performance recovery in which a given deposit removal control is executed in which a deposit accumulating inside the combustion chamber is removed when the performance quality of the in-cylinder pressure sensor is determined to fall below a given reference value, and a second determination in which the performance determination is carried out again after the performance recovery. In the second determination, the in-cylinder pressure sensor is diagnosed as abnormal when the performance quality of the sensor is determined to fall below the given reference value.

Methods and systems are provided for diagnosing temperature sensors of a vehicle. In one example, a method may include, at a duration after an engine-off event, determining that an intake air temperature measured by an intake air temperature sensor of the vehicle is less than an ambient air temperature measured by an ambient air temperature sensor of the vehicle. In response to the determining, the method may include flowing air from a catalyst across the intake air temperature sensor; and indicating the intake air temperature sensor is functional responsive to the intake air temperature converging to the ambient air temperature during the flowing.

A system and method is provided for estimating engine exhaust nitrogen oxide sensor signal instability in transient conditions, for example when rapid changes occur in driver demanded torque, and for eliminating fluctuations in EONOx sensor signal status, in order to have more robust on-board diagnostics monitoring and exhaust nitrogen oxide control. The system and method predicts EONOx sensor signal instability by comparing a calculated pedal based driver demand torque delta to calculated instability thresholds and instability threshold hysteresis margins, and generates instability flags. The system and method further validates any predicted EONOx sensor signal instability by observation. Upon validation of the predicted EONOx sensor signal instability, the system and method latches the EONOx sensor signal status to a stable value.

A control unit controls a combustion state of an internal combustion engine based on a detection value of a temperature sensor. A monitor unit calculates an estimated torque of actual torque of the internal combustion engine and calculates an engine-requested torque requested for the internal combustion engine and to monitor whether the estimated torque differs from the engine-requested torque by an amount that is more than or equal to a predetermined criterion. A detection abnormality determination unit determines whether a detection value or behavior of the detection value is abnormal. The monitor unit includes: a normal-state torque calculation unit to calculate an estimated torque by using the detection value when the detection abnormality determination unit does not determine an abnormality; and an abnormal-state torque calculation unit to calculate an estimated torque by inhibiting using of the detection value when the detection abnormality determination unit determines an abnormality.

A gas sensor element comprising a long plate-like element body and a porous protective layer protecting a surface of the element body, wherein the element body has a gas detection part at an end thereof on one end face side in a longitudinal direction, and the protective layer includes an end face part covering the one end face in laminate, side face parts covering side faces connected to the one end face in laminate, and corner parts where two adjacent ones of the end face part and the side face parts meet. An outer surface of one or more of the end face part and the side face parts has a concave shape that is smoothly continuous with the corner parts and configured such that a layer thickness increases toward the corner parts.

A method for an alternate control of a continuously variable valve duration (CVVD) malfunction may include a CVVD failsafe control to resolve a calculation error of a cylinder charge amount due to a hardware failure of a CVVD system with the cylinder charge amount determined by any one of flow rate alternate, flow rate deviation correction, and valve duration update if the hardware failure is recognized by a CVVD controller, and to apply the cylinder charge amount to secure an air amount for a combustion chamber.

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.

A machine has a power source and a cooling system configured to circulate coolant between the power source and a heat exchanger. The cooling system has a first sensor configured to sense an ambient temperature and provide a first signal indicative of the ambient temperature and a second sensor configured to sense an actual temperature of the coolant and to provide a second signal indicative of the actual coolant temperature. The cooling system has a controller in communication with the first and second sensors to receive the first and second signals. The controller is configured to calculate, based on the ambient temperature and on a model for the heat exchanger, a predicted coolant temperature, and to compare the predicted coolant temperature to the actual coolant temperature. The controller is further configured to provide an alert based at least in part on the comparison.

A machine has a power source and a cooling system configured to circulate coolant between the power source and a heat exchanger. The cooling system has a first sensor configured to sense an ambient temperature and provide a first signal indicative of the ambient temperature and a second sensor configured to sense an actual temperature of the coolant and to provide a second signal indicative of the actual coolant temperature. The cooling system has a controller in communication with the first and second sensors to receive the first and second signals. The controller is configured to calculate, based on the ambient temperature and on a model for the heat exchanger, a predicted coolant temperature, and to compare the predicted coolant temperature to the actual coolant temperature. The controller is further configured to provide an alert based at least in part on the comparison.

A pressure sensor malfunction determination device for a fuel tank includes a fuel tank that stores fuel, a canister that absorbs an evaporated fuel gas and includes a drain port opened to atmosphere, an evaporation path communicating with the canister and fuel tank, a purge gas path communicating with an engine inlet system and the canister, a pressure sensor that detects a pressure, a solenoid valve that opens/closes the evaporation path, and a control unit that controls an opening/closing state of the solenoid valve. When the fuel tank pressure is one of predetermined positive and negative pressure states, the control unit performs valve-opening control on the solenoid valve. The control unit includes a pressure sensor malfunction determination unit that, when an output value of the pressure sensor detected under an atmospheric pressure condition corresponds to a pressure other than the atmospheric pressure, determines that the pressure sensor is malfunctioning.