Methods and systems are disclosed for operating an engine that includes a knock control system. The method and system may increase opportunities to learn one or more engine knock background noise levels via changing poppet valve timing and/or fuel injection timing. The method and system may also improve knock detection if knock sensor degradation is suspected.

A control system for use in a fluid flow application includes a heater and a control device. The heater has at least one resistive heating element and the heater is operable to heat fluid. The control device determines at least one flow characteristic of a fluid flow based on a heat loss of the at least one resistive heating element and determines a mass flow rate of the fluid based on the at least one flow characteristic and a property of the at least one resistive heating element. And the property of the at least one resistive heating element includes a change in resistance of the at least one resistive heating element under a given heat flux density.

A method for operating a heater system including a resistive heating element having a material with a non-monotonic resistivity vs. temperature profile is provided. The method includes heating the resistive heating element to within a limited temperature range in which the resistive heating element exhibits a negative dR/dT characteristic, operating the resistive heating element within an operating temperature range that at least partially overlaps the limited temperature range, and determining a temperature of the resistive heating element such that the resistive heating element functions as both a heater and a temperature sensor. The resistive heating element can function as a temperature sensor in a temperature range between about 500 C. and about 800 C., and the non-monotonic resistivity vs. temperature profile for the material of the resistive heating element can have a local maximum and a local minimum.

The invention relates to a method (100) for operating a solenoid valve (1) for metering a fuel (2) in a fuel injection system (3). The solenoid valve can be actuated against a restoring force (12) by an electromagnet (11), wherein the time curve l(t) of the current I flowing through the electromagnet (11) and/or the time curve U(t) of the voltage U applied to the electromagnet (11) are detected during at least one opening process of the solenoid valve (1). The opening time t.sub.ON and the closing time t.sub.OFF of the solenoid valve (1) are evaluated (110) from the time curve I(t) and/or U(t), and the actual opening duration T.sub.T=t.sub.OFFt.sub.ON of the solenoid valve (1) is compared (140) with a reference value T.sub.R and/or the mass flow dm/dt flowing through the solenoid valve (1) is detected (120) and compared (142) with a reference value M.sub.R during at least one opening process of the solenoid valve (1); and/or a leakage dm/dt of fuel (2) through the solenoid valve (1) is detected (130) in the closed state of the solenoid valve (1). The invention also relates to a corresponding controller (5), a fuel injection system (3), and a computer program product.

A failure diagnosis method of a coolant temperature sensor for a vehicle, may include determining, by a controller, whether or not it is in a flow stop state that stagnates the flow of coolant by a flow control valve; obtaining, by the controller, an engine outlet coolant model temperature when it is in the flow stop state; and diagnosing, by the controller, as a failure of an engine outlet-side outlet water temperature sensor when the coolant model temperature is equal to or greater than a reference temperature and the flow stop state is maintained by the flow control valve.

An electronic control unit (ECU) obtains outside air humidity information from a sensor disposed outside a vehicle compartment and inside air humidity information from a sensor inside the vehicle compartment. The ECU includes a humidity information obtainer obtaining the inside air humidity information, a humidity change calculator calculating the inside air humidity information as a difference between (i) a physical quantity correlated with humidity before a start of a dehumidification or a humidification and (ii) a physical quantity correlated with humidity after a switch-off of the dehumidification or the humidification, a soak time calculator calculating, based on the difference of the physical quantities, a soak time from the switch-off of the dehumidification or the humidification to a sensor-diag startable time at which a diagnosis of the outside air humidity sensor is startable, and a comparator comparing the outside air humidity information and the inside air humidity information after a lapse of the soak time from the switch-off of the dehumidification or the humidification.

A failure diagnosis device for an in-cylinder pressure sensor includes an in-cylinder pressure sensor, and a controller comprised of circuitry configured to execute a diagnosis module into which a signal of the in-cylinder pressure sensor is inputted and configured to diagnose a failure of the sensor based on the signal. The diagnosis module includes a reading module configured to read the signals of the in-cylinder pressure sensor at a first timing that is a timing retarded by a specific crank angle from a compression top dead center, and at a second timing that is a timing advanced by the specific crank angle from the compression top dead center, and a failure determining module configured to determine that the in-cylinder pressure sensor has failed when the failure determining module determines that a difference between signal values at the first timing and at the second timing exceeds a predefined threshold.

In a variable valve control device, a variable valve control system and a method for controlling a variable valve mechanism according to the present invention, An ECM (201) transmits a phase detection value (RA1) computed based on a crank angle signal (CRANK) and a cam angle signal (CAM) to a VTC control unit (202) via a communication network (211), and VTC control unit (202) computes a phase detection value (RA2) based on a motor angle signal (MAS), controls a variable valve timing mechanism (114) based on phase detection value (RA2) in the transient state of an internal combustion engine, and controls variable valve timing mechanism (114) based on phase detection value (RA1) in the steady state of the internal combustion engine.

A heater is provided that includes at least one resistive heating element having a material with a non-monotonic resistivity vs. temperature profile and exhibiting a negative dR/dT characteristic over a predetermined operating temperature range along the profile. The heater can include a plurality of circuits disposed in a fluid path to heat fluid flow.

A heater system for an exhaust system is provided. The heater system includes a heater disposed in an exhaust conduit. The heater includes a plurality of heating elements disposed in the exhaust conduit. A heating control module controls the plurality of heating elements differently according to operating conditions specific to each heating element. In other forms, the heater system for an exhaust system has a plurality of heating zones, instead of a plurality of heating elements. The heating control module controls the plurality of heating zones differently according to operating conditions specific to each heating zone.