A heavy-duty truck has a diesel engine, an exhaust after-treatment system, and an engine control unit. The exhaust after-treatment system includes a close-coupled selective catalytic reduction system and an underbody selective catalytic reduction system, a first NO.sub.x sensor upstream of the close-coupled selective catalytic reduction system, a second NO.sub.x sensor between the two selective catalytic reduction systems, and a third NO.sub.x sensor downstream of the underbody selective catalytic reduction system. The engine control unit may perform methods allowing intrusive diagnostics to be performed on exhaust gas NO.sub.x sensors using the selective catalytic reduction systems during normal operation of the heavy-duty truck.

A method determines a sensor error of a sensor in an exhaust gas system of a motor vehicle. One step of the method involves determining at least one actual sensor signal of the sensor. Another step of the method involves determining at least one target sensor signal of the sensor by means of a model. A further step of the method involves determining the sensor error of the sensor according to a deviation between the actual sensor signal of the sensor and the target sensor signal of the sensor.

A method for monitoring an operation of an internal combustion engine includes the steps of: detecting, during the operation of the internal combustion engine, an acoustic signal, at least partially, during a closing process of a gas exchange valve of the internal combustion engine; evaluating, based on the acoustic signal which is detected, at least one functional state of the internal combustion engine; and selecting the at least one functional state of the internal combustion engine from a group consisting of a state of the gas exchange valve and a state of a structure-borne noise sensor used to detect the acoustic signal.

A gas sensor includes a housing including a locking step part, a sensor body including a locked part locked to the locking step part, a sealing member filled between an inner periphery of the housing and an outer periphery of the sensor body on a base end side of the locked part, an insulating member disposed on the base end side of the sealing member, and a circular disc spring pressing a base end surface of the insulating member. The housing includes a caulking part caulking the circular disc spring to cover the circular disc spring. The elastically compressed circular disc spring is disposed between the caulking part and the insulating member. At least part of a base end side pressing part, at which the caulking part presses the circular disc spring, is disposed between an inner and outer periphery edges of the base end surface of the insulating member.

Upon receiving a request to stop an internal combustion engine, processing circuitry of a fuel supply device opens a relief valve by increasing a fuel pressure in a delivery pipe to a specified pressure or greater before stopping the internal combustion engine. The processing circuitry determines whether a fuel pressure sensor is normal based on a result of comparison between a fuel pressure in the delivery pipe detected by the fuel pressure sensor and a fuel pressure determination value after the fuel pressure in the delivery pipe starts to decrease as a result of opening the relief valve.

A method executed by at least one server, comprising: receiving, from a first monitored system comprising an internal combustion engine and a first sensor, a first signal associated with a first occurrence and a second occurrence of an internal combustion engine event and first measurement data of the first sensor; determining a first measurement from the first measurement data and a second measurement from the first measurement data based on the first and second occurrences, respectively; determining a reference measurement; determining a first reference deviation; determining a second reference deviation; after determining the first reference deviation is less than a first reference threshold and the second reference deviation is less than a second reference threshold, determining a measurement deviation; comparing the measurement deviation to a measurement threshold; and after determining the measurement deviation satisfies the measurement threshold, determining a first exhibited useful life of the first sensor.

A diagnostic device for a sensor for measuring the position of a motor-vehicle drive shaft. The sensor includes a first wired communication link and a second wired communication link, via which wired communication links the sensor sends the signal, and being characterized by an average reference voltage. The diagnostic device for a sensor being intended to be electrically connected between the first wired communication link and the second wired communication link and being configured to: a) receive a first voltage value corresponding to the average voltage in the first wired communication link and a second voltage value corresponding to the average voltage in the second wired communication link; b) detect a short circuit on the first wired communication link; or c) detect a short circuit on the second wired communication link.

An electrically heated catalyst device has a catalyst that purifies exhaust gas from an engine, and is configured to heat the catalyst with electric power that is supplied from an electric storage device. A current sensor detects a current that is supplied to the electrically heated catalyst device. A current sensor detects an input/output current of the electric storage device. A controller executes failure determination control to determine whether the current sensor has a failure. In the failure determination control, the controller estimates a current that is supplied to the electrically heated catalyst device using a detection value of the current sensor and compares the estimated current with a detection value of the current sensor to determine whether the current sensor has a failure.

In a particulate detection system (10), a control board (911), a high voltage generation board (913) and an isolation transformer (720) are respectively disposed in a first space (921d) and a second space (921e) separated from each other by an inner case (923). When electromagnetic noise is generated in the high voltage generation board (913) and the isolation transformer (720); specifically, at the primary winding of the isolation transformer 720, at the time of switching the primary current supply, the electromagnetic noise is blocked by the inner case (923). This configuration reduces the influence of electromagnetic noise generated in the primary winding on the control board (911).

The present invention relates to a system for coping with a malfunction of an ethanol sensor of a FFV. The present invention provides a system for coping with a malfunction of an ethanol sensor of a FFV, the system including: a driving condition detector configured to determine whether a driving condition of the FFV is satisfied; an air-fuel ratio control condition detector configured to determine whether an air-fuel ratio control condition is satisfied; a timer unit configured to calculate a timer value by measuring time when an ethanol content value measured in the ethanol sensor is constant and when the driving condition and the air-fuel ratio control condition are satisfied; and a controller configured to synchronize an ethanol-content learned value with the ethanol content value measured in the ethanol sensor when it is determined that the timer value calculated in the timer unit is higher than a preset critical value.