A method and system for monitoring an exhaust gas sensor coupled in an engine exhaust is provided. In one example, the method determines an estimate of an exhaust gas oxygen sensor time constant according to a comparison of air/fuel ratios and a system time constant.

A control device for an in-vehicle unit installed in a vehicle having a warning light includes a control circuit and a storage circuit. The control circuit executes an abnormality detection process, a detection result write-in process, and a lighting request output process. The storage circuit retains contents of the history information even when the in-vehicle unit is powered on or powered off. The control circuit is configured to retrieve the contents of the history information from the storage circuit when the in-vehicle unit is powered on. When the detection history is written in the retrieved contents, the control circuit outputs the lighting request even when an abnormality of the in-vehicle unit cannot be detected by the abnormality detection process.

An engine malfunction determination system includes a vehicle engine, an engine sensor system, an engine control module and an electronic display device. The engine sensor system has at least one sensor configured to detect an operation condition of the vehicle engine. The engine control module is in electrical communication with the sensor system to receive a detection signal from the engine sensor system regarding the operation condition of the vehicle engine. The engine control module is programmed to determine an anomaly in the detection signal. The electronic display device is programmed to display an indication of engine malfunction when the engine control module determines that the anomaly in the detection signal exceeds a predetermined threshold.

An internal combustion engine system includes a first set of cylinders, a second set of cylinders, exhaust manifolds, and exhaust gas sensors. The first set of cylinders has first and second subsets of cylinders. The second set of cylinders has third and fourth subsets of cylinders. The exhaust manifolds have primary conduits, secondary conduits branching from the primary conduits, and tertiary conduits branching from the secondary conduits. The tertiary conduits associated with each of the secondary conduits are connected to one of the first, second, third, or fourth subsets of cylinders. The exhaust gas sensors are disposed within each of the secondary conduits and are each configured to measure air-to-fuel ratios of one of the first, second, third, or fourth subsets of cylinders.

A urea water supply guidance output device for a working vehicle includes: a urea water residual amount detection unit configured to detect a urea water residual amount in a urea water tank; an operation time measurement unit configured to measure an operation time of the working vehicle; a unit urea water consumption amount calculation unit configured to calculate a unit urea water consumption amount for each predetermined unit operation time; a urea water remaining time calculation unit configured to calculate an average urea water consumption amount and to calculate a urea water remaining time indicating a time to generation of urea water supply alarm; and an output processing unit configured to output guidance including the urea water remaining time when the urea water remaining time is a predetermined time or less.

A method of predicting the temperature of a resistive heating element in a heating system is provided. The method includes obtaining resistance characteristics of resistive heating elements and compensating for variations in the resistance characteristics over a temperature regime. The resistance characteristics of the resistive heating element include, but are not limited to, inaccuracies in resistance measurements due to strain-induced resistance variations, variations in resistance due to the rate of cooling, shifts in power output due to exposure to temperature, resistance to temperature relationships, non-monotonic resistance to temperature relationships, system measurement errors, and combinations of resistance characteristics. The method includes interpreting and calibrating resistance characteristics based on a priori measurements and in situ measurements.

Various methods and systems are provided for a multi-fuel capable engine. The system includes a liquid fuel system to deliver liquid fuel to an engine, a gaseous fuel system to deliver gaseous fuel to the engine, and a control system. The control system, during a gaseous fuel system test mode, controls the liquid fuel system and the gaseous fuel system to deliver the liquid fuel and the gaseous fuel to the engine over a range of engine operating points, and indicate degradation of the gaseous fuel system based on engine output at each of the engine operating points.

A positive crankcase ventilation (PCV) system for an engine includes: a PCV tube defining a flowpath extending along an axis; a damage detection circuit associated with the PCV tube. The PCV system also includes a damage detection module that selectively indicates that a fault is present in the PCV tube based on a change in a characteristic of the damage detection circuit and that illuminates a malfunction indicator lamp (MIL) when the fault is present.

A control apparatus for an internal combustion engine is configured to: calculate measured data of MFB based on in-cylinder pressure detected by an in-cylinder pressure sensor; execute engine control based on a measured value of a specified fraction combustion point that is calculated based on the measured data of MFB; and calculate a first correlation index value for the measured data (current data) and the reference data of MFB and a second correlation index value for the current data and the immediately preceding past data. The engine control is suspended that uses the measured data of the specified fraction combustion point based on the current data when both of the first correlation index value and the second correlation index value are less than a determination value.

An exhaust system is provided that includes at least one exhaust aftertreatment unit provided in an exhaust fluid flow pathway and a thermal storage device disposed upstream from the exhaust aftertreatment unit. The thermal storage device is operable to store thermal mass and provide thermal insulation to enable a catalyst to maintain a minimum predetermined temperature for a minimum predetermined time. In one form, a heater is also provided proximate the thermal storage device, along with variations that include a secondary flow pathway for the thermal storage device.