A method of operating an oxygen sensor system is provided where the system includes an oxygen sensor, the oxygen sensor including a pump cell, and wherein the oxygen sensor is connected to associated circuitry such that the associated circuitry controls operation of the pump cell. The pump cell includes a pump line connected to a pump electrode of the pump cell and a return line connected to a return electrode of the pump cell. The method includes, subsequent to a diagnostic process, raising the potential of the pump line for a predetermined period of time by injecting current onto the pump line.

A controller includes a soak timer, a nonvolatile memory, and a determining section. The determining section is configured to perform a rationality check on a condition that a performance condition is met. The determining section is also configured to make the performance condition strict when an obtained index value of a vehicle outside temperature, that is obtained when an elapsed amount of time reaches a specified amount of time, and the determining section is activated, is higher than a stored index value of the vehicle outside temperature stored in the nonvolatile memory.

New and/or alternative approaches to determine mass flow using a flow measurement device in a pulsatile flow context. The flow measurement device is configured to generate a delta-pressure measurement. A semi-physical valve model is generated for the flow measurement device, and the delta-pressure measurement is then is isolated using the model. A discharge coefficient map is determined for the flow measurement device by testing using sets of operating parameters for a system. The operating parameters of the system are then used to determine the discharge coefficient for use in estimating mass flow with the semi-physical valve model. The resultant estimated mass flow can be used to control the system, and a Factor of Effective Area estimate generated using the valve model can be used to determine the status of the flow measurement device and identify or predict a need for maintenance.

A method and a device for performing diagnostics on an exhaust gas sensor includes a series circuit of a Nernst cell and a first other cell. The exhaust gas sensor has a first, a second, and a third connection where a voltage drop can be measured between the first connection and the second connection by the Nernst cell and a voltage drop between the second connection and the third connection can be measured by the first other cell. The diagnostic method has steps for feeding a direct or alternating current into the first, second, and third connections; for directly or indirectly sensing an electrical voltage potential at at least one of the first, second, and third connections; and for evaluating the voltage potential sensed to diagnose a short circuit or an open circuit in the Nernst cell and/or in the first other cell.

Provided is a control device configured to be able to execute, in an engine which includes a DOC, a DPF, and a temperature increase unit including an exhaust throttle valve, for increasing a temperature of each of the DOC and the DPF, a forced regeneration process of removing PM deposited on the DPF by increasing the temperature of the DPF. The control device includes a flow rate estimation part configured to estimate an intake flow rate of a combustion gas sent into a cylinder of the engine. The flow rate estimation part is configured to estimate a first intake flow rate, which is the intake flow rate in the forced regeneration process, from an opening degree of the exhaust throttle valve and a first state amount which indicates an operation state of the engine including a rotation speed of the engine, based on a first relationship representing a relationship between the first intake flow rate, and the opening degree of the exhaust throttle valve and the first state amount, in the forced regeneration process.

Systems, apparatuses and methods for systematically executing a diagnosis and fault isolation of a failure condition for an engine during a cranking test of the engine. Examples of the failure condition include, but are not limited to, cylinder-by-cylinder compression conditions, excessive blow-by conditions, valve failures, leaks, and/or obstructions of the intake, exhausts, crankcase ventilation, and/or exhaust gas recirculation systems.

A method for monitoring a sensor arranged in the exhaust gas region of an internal combustion engine. The method includes determining a sensor temperature using the sensor, determining a model temperature of the sensor, integrating changes in the sensor temperature and integrating changes in the model temperature if the changes in the sensor temperature exceed a predetermined first threshold value and the changes in the model temperature exceed a predetermined second threshold value, and comparing the integral of the changes in the sensor temperature with a predetermined fourth threshold value.

A method for determining a function criterion of a measuring transducer of a motor vehicle, comprising: determining, with the aid of preconditions, whether a predefined vehicle state of the motor vehicle is present; capturing measured values of at least three measuring transducers which measure the same measured variable; calculating a measure of central tendency from the captured measured values; calculating a comparison value from the captured measured value with respect to the calculated measure of central tendency; ascertaining the function criterion of the measuring transducer, based on a comparison of the calculated comparison value with a threshold value, the capture of the measured values being carried out within a time period after the initialization of the controller, the ascertained function criterion being determined if the preconditions have been met and the provided vehicle state is thus present.

An EHC line leakage diagnosis method can operate a heater of an oxygen detector when satisfying one or more conditions of an engine off time, a coolant temperature, and an outside air temperature by a diagnosis controller upon the key-on of the non-operation of an engine, and then, determine the normality or abnormality of a temperature drop using a change in a temperature value of a signal value and the temperature value detected by the oxygen detector after an air pump is driven, and then confirm the leakage of an exhaust line and a line on the rear end portion of an EHC valve of an air line using the number of times of the occurrence of the abnormality of the temperature drop, and can perform the failure diagnosis without generating the exhaust gas by not operating an engine.

Disclosed is a method for diagnosing a speed/position sensor of an internal combustion engine, of the type including a toothed wheel, which rotates as one with a shaft, and a matter detector, which is arranged so as to be fixed opposite the toothed wheel and controls a base of a transistor. The method includes: detecting a short circuit between an output of the speed/position sensor and a power supply; and testing for excess current consumption by a power supply of the speed/position sensor when the transistor is activated. If the test is positive, the short circuit is identified between the power supply of the speed/position sensor and the output of the speed/position sensor. Alternatively, if the test is negative, the short circuit is identified between another power supply and the output of the speed/position sensor.