For diagnosing a proper functioning of an auxiliary heater in an air mass sensor in an engine system including an internal combustion engine, the auxiliary heater being used for preventing contamination of a sensor area, the air mass sensor communicating air mass information via a signal line during a sensor operating mode and, if a specified state on the signal line is detected, activating the auxiliary heater, the following are performed: setting the state of the signal line to the specified state for a predefined time period in an auxiliary heater operating mode; transmitting a first temperature information before the activation of the auxiliary heater operating mode and a second temperature information via the signal line after expiration of the predefined time period; and detecting the proper functioning of the auxiliary heater depending on the difference between the first temperature information and the second temperature information.

The present invention relates to a method for diagnosing an exhaust gas system of an internal combustion engine with at least one three-way catalytic converter, at least one four-way catalytic converter and at least one binary lambda sensor, wherein during the testing of the functional operability of the at least one binary lambda sensor and/or of at least one four-way catalytic converter on the basis of a lambda change with a changeover of the internal combustion engine from a lean operation to a rich operation following a thrust operation clearing out at least one three-way catalytic converter occurs.

Rationality diagnostic techniques for an intake oxygen sensor are utilized to detect sensor malfunction. A non-intrusive diagnostic technique includes passively detecting when an exhaust gas recirculation (EGR) valve position crosses low/high position thresholds, whereas an intrusive diagnostic technique includes actively commanding the EGR valve to predetermined low/high positions. During a period after the EGR valve position reaches/crosses at least one of the low/high positions/position thresholds, respectively, maximum and minimum intake oxygen concentration is monitored. When the EGR valve position has crossed both the low/high positions/position thresholds and a difference between the maximum and minimum oxygen concentrations is less than a respective difference threshold, a malfunction of the intake oxygen sensor is detected. A malfunction indicator lamp (MIL) could be set to indicate the malfunction. The intrusive technique is additionally or alternatively implemented, such as part of a verification or backup to the non-intrusive technique.

A heater control apparatus of a fuel filter for a vehicle includes a heater mounted within a fuel filter; a relay for a heater power source supplying or interrupting power of a battery to or from the heater; a fuel temperature detection sensor mounted on an engine and detecting a temperature of a fuel; and an engine electronic control unit (ECU) for switching on and off the relay based on a detection signal of the fuel temperature detection sensor.

Methods and systems are provided for performing rationality check of a hydrocarbon sensor in an evaporative emission control system. In one example, a method may include sensing fuel vapors vented from a fuel vapor canister to atmosphere via the sensor, and performing sensor rationality check by flowing desorbed hydrocarbons from the fuel vapor canister to an engine via the sensor during purging of the fuel vapor canister.

A method for diagnosing a malfunction of a sensor system in an air system of an internal combustion engine, said sensor system comprising a first air state sensor, a second air state sensor and a third air state sensor, wherein a first value and a second value of a first comparison variable are ascertained in two different ways in an overall calculation step such that the result of a comparison between the first value and the second value is a function of each of the output variables of the first, second and third air state sensors and wherein in a fault detection step, said method recognizes as a function of the comparison between said first value and said second value of the comparison variable that a fault exists in the sensor system.

A method for operating a probe having a pumped reference cell. A pulse-width-modulated pump current is applied to the reference cell at a first point in time. In accordance with the first point in time, a first voltage characteristic value (representing the voltage applied to the reference cell) is determined within a first time frame. The pulse-width-modulated pump current applied to the reference cell is switched off at a second point in time. A third point in time is determined, at which a pulse-width-modulated pump current applied to the reference cell is switched off. In accordance with the third point in time, a second voltage characteristic value (representing the voltage applied to the reference cell) is determined within a second time frame. The first and second voltage characteristic values are used to determine a diagnostic characteristic value, which is representative of an error in determining the nitrogen oxide concentration.

Methods and systems are provided for determining barometric pressure. In one example, an onboard vacuum pump is utilized to draw a vacuum at a constant flow rate across a reference orifice, and the resulting vacuum level is converted to a barometric pressure. In this way, other sensors for determining barometric pressure in a vehicle may be rationalized without the use of engine operation, and in an example where the other sensors for determining barometric pressure are not functioning as desired, barometric pressure as inferred from the onboard pump may be utilized to adjust engine operation.

A particulate detection device has an insulation part, electrodes, an adhesion amount calculation section, a heater and a controller. The insulation part is located in an exhaust passage of an internal combustion engine and has an adhesion surface to which exhaust particulates emitted from the internal combustion engine adhere. The adhesion amount calculation section calculates an adhesion amount of the exhaust particulates adhered to the insulation part based on an electrical resistance between two of the electrodes. The controller, in a normal control, controls an air/fuel ratio in the internal combustion engine to be a theoretical air/fuel ratio. The controller, in a regeneration control, controls the heater to increase a temperature of the insulation part and removes the exhaust particulates from the insulation part by burning the exhaust particulates, and controls the air/fuel ratio to be lean as compared to the theoretical air/fuel ratio.

A method for operating a common-rail system of a motor vehicle that includes a common-rail-pressure sensor configuration having at least two signal paths, and that can be operated at a maximally permissible common-rail pressure and at a minimally permissible common-rail pressure. Sensor signals are read out in each case in response to a pressure measurement in a common rail of the common-rail system via the at least two signal paths, and a signal deviation value is ascertained that characterizes a deviation between the pressure values that are each determined on the basis of the sensor signals. The method includes reducing the maximally permissible common-rail pressure by a correction value to a maximally permissible emergency common-rail pressure and/or increasing the minimally permissible common-rail pressure by a correction value to a minimally permissible emergency common-rail pressure in response to the signal deviation value exceeding a predefined value.