A heating system includes at least one electric heater disposed within the fluid flow system. A control device includes a microprocessor and is configured to determine a temperature of the at least one electric heater based on a model and at least one input from the fluid flow system. The control device is configured to provide power to the at least one electric heater based on the temperature of the at least one electric heater.

Embodiments for diagnosing a humidity sensor are provided. One example method comprises, responsive to a humidity sensor test cycle, pumping air conditioning and windshield washer gas flows past a humidity sensor, and indicating humidity sensor degradation based on a response of the humidity sensor to the air conditioning and windshield washer gas flows. In this way, degradation of the humidity sensor may be indicated if the humidity sensed by the humidity sensor does not change responsive to the humidity sensor test cycle being initiated.

In automatic stopping of the internal combustion engine, an electronic control unit controls a heater so that an element temperature of the air-fuel ratio sensor becomes a first temperature. The first temperature is a temperature that is below an activation temperature range in which the air-fuel ratio sensor is activated, and is also below a desorption temperature range in which HC components adsorbed on the air-fuel ratio sensor desorb therefrom. In a case where, after the element temperature of the air-fuel ratio sensor becomes the first temperature, it is estimated that the amount of HC components adsorbed on the air-fuel ratio sensor increases to exceed a first predetermined amount, the electronic control unit controls the heater so that the element temperature of the air-fuel ratio sensor becomes a second temperature. The second temperature is a temperature included in the desorption temperature range.

Methods and systems are provided for reducing soot sensor electrode degradation in harsh chemical environment introduced as a result of desulfation of a lean NOx trap positioned upstream of the soot sensor. In one example, a method may include in response to the SOx load being higher than the threshold, prior to initiating desulfation of LNT, operating the soot sensor in a pre-desulfation mode where the negative electrode is connected to the positive electrode for a brief duration, while the positive electrode is disconnected from the positive electrode. However during desulfation, when H.sub.2S is released as a by-product, both the electrodes may be open, i.e. not connected to the positive electrode or ground, thereby reducing the possibility of sensor degradation.

Embodiments of the present invention provide a method and a system for controlling fuel supply of a dual-fuel vehicle. The method includes: detecting an operation status of a pressure sensor by an electronic control unit, when an engine is at a gas state; receiving a pressure signal of the pressure sensor by the electronic control unit, when the pressure sensor works properly, the pressure signal indicating internal pressure of a gas tank; and controlling the engine to switch to fuel state by the electronic control unit, when the duration time of the internal pressure of the gas tank less than or equal to a predetermined pressure is greater than or equal to a predetermined time. The method can accurately control switching states according to the remainder of the gas in the gas tank, therefore avoid the engine frequent gas-fuel.

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.

Examples of the present disclosure describe systems and methods for determining an estimated ambient air temperature in an environment in which a vehicle is operating. The estimated ambient air temperature may be compared to an ambient temperature sensor value. The comparison may be used to determine whether an ambient air temperature sensor of the vehicle is functioning properly or if an error notification or fault code should be triggered.

Examples of the present disclosure describe systems and methods for determining a state of an air diverter valve of an air induction system of a vehicle. The determined state of the air diverter valve may be based on an intercooler-based estimated ambient air temperature and a comparison between an ambient air temperature sensor value and a pre-compressor sensor value.

A method of predicting manifold air pressure in an internal combustion engine during idle comprising the steps of receiving an idle air control (IAC) duty cycle value from an idle air controller, receiving an atmospheric pressure, and predicting a manifold pressure in an engine control unit based on the IAC duty cycle value and the atmospheric pressure.

Disclosed is a method for acquiring an altitude correction coefficient, comprising: acquiring an initial value of an altitude correction coefficient self-learning filter when a preset event occurs to a vehicle engine, the preset event includes a power-off event, a power-on event, and an unexpected power-down event; evaluating whether the vehicle satisfies a preset self-learning enabling condition, in accordance with an engine rotation speed, a vehicle speed, and status information of designated devices; enabling the altitude correction coefficient self-learning filter when the vehicle satisfies the preset self-learning enabling condition; determining an input of the altitude correction coefficient self-learning filter at least in accordance with operating states of a manifold pressure sensor and a stepping motor; and obtaining a current altitude correction coefficient by self-learning the altitude correction coefficient applying the altitude correction coefficient self-learning filter in accordance with the initial value of the altitude correction coefficient self-learning filter and the input of the altitude correction coefficient self-learning filter. An apparatus for acquiring an altitude correction coefficient is also disclosed. The above method and apparatus improve the accuracy of the altitude correction coefficient and enhance the idling satiability.