A control unit (6) estimates an output value of a PM sensor (S2) located at a downstream side of a DPF used as a reference filter, and detects whether the estimated output value exceeds a predetermined value (S3). When the estimated output value exceeds the predetermined value (YES in S3), the control unit detects an output value of the PM sensor (S4), and a heater heats the PM sensor (S5). The control unit detects an output value of the PM sensor (S6) after the PM sensor is heated, and calculates a change ratio of the output values of the PM sensor before and after heating (S7). The control unit estimates an average particle size of PM based on the calculated change ratio (S8), and detects whether the DPF has failed based on a comparison result of a corrected output value of the PM sensor with a threshold value.

An engine management apparatus for a vehicle having a fuel ratio controller arranged to control the air to fuel ratio of a fuel mixture for the vehicle's engine, a power demand sensor arranged to sense power demands made of the engine, and an engine controller configured to increase the air to fuel ratio from a first selected value to a second selected value in the event that the rate of vehicle speed change is less than a first threshold and the demand is less than a second threshold.

An air-fuel ratio detection device 1, 1 comprises: a sensor element 2, 2 including a sensor cell 10; a voltage application circuit 40, 40 applying voltage to the sensor cell; a current detector 42, 42 detecting an output current of the sensor cell; an air-fuel ratio calculating part 61 configured to calculate an air-fuel ratio of an exhaust gas; and a parameter detecting part 62 configured to detect or calculate a temperature correlation parameter correlated with a temperature of the sensor element. The air-fuel ratio calculating part is configured to calculate the air-fuel ratio of the exhaust gas based on the temperature correlation parameter and the output current detected when a predetermined voltage is applied to the sensor cell.

Provided is an engine control device for correcting output characteristics of an oxygen sensor and performing air-fuel ratio feedback control. The engine control device includes various sensors for detecting operating state information of an engine, an oxygen sensor, and air-fuel ratio feedback controller to adjust an amount of fuel injected into the engine, on the basis of the operating state information and an output voltage value of the oxygen sensor, wherein the air-fuel ratio feedback controller calculates, in accordance with the operating state information based on detection results from the various sensors, a coefficient for correcting the output voltage value, implements air-fuel ratio feedback control on the basis of an air-fuel ratio feedback control correction amount calculated using a corrected oxygen sensor output voltage value calculated on the basis of the coefficient, and adjusts the amount of fuel injected into the engine.

An interface circuit assembly for use with an electronic control unit and oxygen sensor of an internal combustion engine. The assembly includes an input port coupled to receive a signal from the oxygen sensor and a processing unit coupled with the input port. The processing unit increases the signal to an output voltage as a function of hydrogen being provided to the internal combustion engine. An output port is coupled with the processing unit and provides the output voltage to the electronic control unit.

An integrated ignition and electronic auto-choke module for an internal combustion engine and an internal combustion engine including the same. In one aspect, the module includes a housing that is configured to be mounted to an engine block of an internal combustion engine. The housing may contain at least a portion of a first temperature sensor that measures a first temperature indicative of an engine temperature. The housing may also contain a controller and at least a portion of an ignition circuit. The controller may be coupled to the first temperature sensor and configured to determine a starting position of a choke valve based on the first temperature and operate an actuator to move the choke valve into the starting position accordingly.

A signal processing apparatus for a gas sensor is applied to a gas sensor that is disposed on an exhaust passage of an engine to detect a concentration of a specific component in exhaust gas flowing through the exhaust passage. The signal processing apparatus includes a filtering means that attenuates exhaust pulsation noise included in a detection signal of the gas sensor, and a filter characteristic setting means that variably sets filter characteristics of the filtering means based on engine speed.

An integrated ignition and electronic auto-choke module for an internal combustion engine and an internal combustion engine including the same. In one aspect, the module includes a housing that is configured to be mounted to an engine block of an internal combustion engine. The housing may contain at least a portion of a first temperature sensor that measures a first temperature indicative of an engine temperature. The housing may also contain a controller and at least a portion of an ignition circuit. The controller may be coupled to the first temperature sensor and configured to determine a starting position of a choke valve based on the first temperature and operate an actuator to move the choke valve into the starting position accordingly.

Fuel injection control of an internal combustion engine requires an optimized fuel amount that can be burned completely with oxygen in intake air to be supplied, but the oxygen concentration in the atmospheric air is affected by humidity.

By separately calculating a dry air flow rate that directly affects the oxygen amount and a humidity flow rate that is a change factor of the oxygen concentration in the intake air of the internal combustion engine, the fuel can be supplied to the cylinder of the internal combustion engine at an optimized air-fuel ratio. In addition, highly precise control involving EGR for flowback of a part of the exhaust gas flowing in the exhaust pipe to the intake pipe can also be achieved.

Provided is a control device for an internal combustion engine equipped with at least one cylinder, an EGR device, and an actuator that is used for control of an engine control parameter that affects the combustion stability. The control device is configured to: perform, if a condensed water occurrence condition is met, a particle size estimation processing that estimates the particle size of the condensed water that flows into the at least one cylinder from the intake channel; and perform, if the condensed water occurrence condition is met, a correction processing that corrects the engine control parameter so as to improve the combustion stability. In the correction processing, the control device more increases a correction amount of the engine control parameter when the particle size estimated by the particle size estimation processing is greater.