A method for a two-point lambda sensor includes, changing a composition of an air/fuel mixture supplied to an internal combustion engine from a predefined lambda value to lambda=1, determining a delay time of the voltage value reaching a value corresponding to the lambda=1, again changing the composition of the air/fuel mixture from the predefined lambda value to lambda=1, determining a characteristic of the changing performed in the second regulation based on the delay time, determining an actual value of lambda on an actual voltage-lambda characteristic curve of the two-point lambda sensor that corresponds to the predefined lambda value which is in reference to a reference voltage-lambda characteristic curve based on the determined characteristic, and identifying a voltage offset between the characteristic curves based on a deviation of the actual value from the predefined value.

A hybrid vehicle has an engine (E) that is capable of changing a combustion mode between a stoichiometric combustion mode and a lean combustion mode and a motor/generator (MG) that is capable of performing torque assist by a power running operation and torque absorption by a regenerative operation. As a boundary between a stoichiometric combustion operating region and a lean combustion operating region, a second boundary (L2) at a torque decrease has a hysteresis at a low torque side with respect to a first boundary (L1) at a torque increase. Upon shift from the stoichiometric combustion operating region to the lean combustion operating region, for delay in increase of an intake-air quantity, decrease in fuel and the torque assist by the motor/generator (MG) are carried out, and an exhaust air-fuel ratio is changed stepwise.

For an engine that draws a complicated torque trajectory, it has been taken a lot of time to adapt a time constant for calculation of estimated torque. Therefore, an ECU 102 includes a target torque calculation unit 203 that calculates target torque of an engine for which torque-based engine control is performed using estimated torque, and an estimated torque calculation unit 210 that calculates the estimated torque by calculating a primary delay coefficient 304 equivalent to a time constant calculated for each control cycle based on a change in an actual intake air amount with respect to a target intake air amount of air sucked into the engine and performing primary delay processing on the target torque using the primary delay coefficient 304.

A first arrival flow rate that is a flow rate of evaporative fuel gas that has arrived in a throttle downstream portion located downstream of a throttle valve in an intake pipe via a second purge passage after passing through a purge control valve is estimated based on a valve passage flow rate that is a flow rate of evaporative fuel gas that has passed through the purge control valve, and a first response delay in the flow of evaporative fuel gas through a route extending from the purge control valve to the throttle downstream portion via the second purge passage.

A method for operating an internal combustion engine having an injection system which has a high-pressure accumulator, high pressure in the high-pressure accumulator being controlled via a suction throttle on the low-pressure side, acting as a first pressure control element in a first high-pressure control loop. During normal operation, a high-pressure disturbance variable is produced by a pressure regulating valve on the high-pressure side, acting as an additional pressure control element, via which fuel is re-directed from the high-pressure accumulator into a fuel reservoir, the at least one pressure regulating valve being controlled, during normal operation, based on a set volumetric flow rate for the fuel to be re-directed. A temporal development of the set volumetric rate is sensed and the set volumetric flow rate is filtered, a time constant for the filtering of the set volumetric flow rate being selected as a function of the sensed temporal development.

Electronic fuel injection control system for an internal combustion engine, the internal combustion engine being equipped with at least one fuel feeding line provided with a fuel tank, at least one throttle valve, at least one injector, at least one fuel pump, at least one fuel return line having at least one solenoid valve, at least one first fuel return duct that connects the injector to the solenoid valve, at least one overpressure valve, at least one second return conduit adapted to connect the overpressure valve and the solenoid valve with the tank, wherein the fuel return line is provided with at least one calibrator allowing at least the state of said fuel pump and relative performances thereof to be verified.

An abnormality detection device for an air-fuel ratio detection device arranged downstream of a filter is equipped with an abnormality detection unit that detects an abnormality in the air-fuel ratio detection device based on output change characteristics of the air-fuel ratio detection device during fuel cutoff control for stopping the supply of fuel to a combustion chamber of an internal combustion engine, and a combustion determination unit that determines whether or not a combustion amount of particulate matter in a filter during fuel cutoff control is larger than a predetermined amount. The abnormality detection unit prohibits detection of an abnormality in the air-fuel ratio detection device when the combustion determination unit determines that the combustion amount is larger than the predetermined amount.

A method of two-step variable valve lift (VVL) malfunction avoidance learning control may include: in a two-step VVL system which is operated with a main lift and a secondary lift, verifying, by an electronic control unit (ECU), an operation avoidance area based on locking of a lock pin of a cam follower ; performing VVL operation learning, in which a failure of occurrence of the second lift is determined on the basis of a locking failure of the cam follower due to an initially set value of the operation avoidance area; and reflecting the operation avoidance area to the two-step VVL system with a corrected set value which is obtained through the VVL operation learning.

A controller includes a memory device and an execution device that executes first and second operation processes, a switching process, and a recording process. The first operation process operates an operated unit by an operated amount, which is calculated on the basis of a state variable, using an adapted data set. The second operation process operates the operated unit by an operated amount that is defined by a relationship defining data set and the state variable. The switching process switches a process that operates the operated unit between the first operation process and the second operation process. The recording process obtains a value of the state variable used in calculation of the operated amount using the first operation process during an operation of the operated unit using the second operation process. The recording process also records time-series data of the obtained value of the state variable in the memory device.

A pressure detection unit detects a fuel pressure in high-pressure fuel passages. A drive control unit controls opening and closing of pressure adjusting valves based on a drive command signal output to the fuel injection valve. An acquisition unit acquires an inflection point of the fuel pressure detected by the pressure detection unit and an inclination of the fuel pressure after the inflection point appears, after an output of the drive command signal. A delay time computation unit computes a response delay time of the pressure adjusting valve with respect to the drive command signal for each of the first on-off valve and the second on-off valve based on the inflection point and the inclination acquired by the acquisition unit.